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February 27, 2003
Multidrug therapy for dry eye
OSN 2003
In December 2002, Advanced Vision Research launched two new TheraTears products: TheraTears Liquid Gel (preservative free) and TheraTears Nutrition for dry eyes.
There is a lot of buzz about using flaxseed oil supplementation to treat dry eyes.We were able to solve the mystery of how flaxseed works in treating dry eye, and make it work better by fortifying it with EPA, DIIA and vitamin E. The blend suppresses meibomitis, augments the oil layer and stimulates tear secretion. As patients take TheraTears Nutrition for 4 to 8 weeks they feel better in the morning because it suppresses the eyelid inflammation that otherwise irritates the ocular surface all night, and they feel better throughout the day because it bolsters the oil layer and promotes tear secretion.TheraTears Liquid Gel is a thicker version of TheraTears Lubricant Eye Drops for nighttime or forpatients who need longer-lasting relief and protection. TheraTears Liquid Gel is the first preservative-free gel,” he said.This is important because the longer a preserved gel or ointment stays in your eye, the more likely you are to experience discomfort from preservative-induced irritation or electrolyte imbalance toxicity.
The introduction of TheraTears Nutrition represents the beginning of a new era in the treatment of dry eye: multidrug therapy.
Posted by mehdi khanlari at 11:02 PM
Sine Amsler Charts: a new method for the follow-up of metamorphopsia
Optholinx
Sine Amsler Charts (SAC) are a set of eight modified Amsler charts where replaced the straight lines by sine curves of the same frequency but with different amplitudes (grades IVIII). The patient first examines a regular Amsler chart with the affected eye; subsequently the SAC are presented in random order to the fellow eye. With this eye the patient then selects the SAC with the amplitude that best corresponds to the metamorphopsia observed with the affected eye. After 30 min the test was repeated. A comparison of pre- and postoperative SAC scores was made in 63 patients. The correlations between preoperative visual acuity, membrane type, leakage on fluorescein angiography, preoperative SAC score, postoperative SAC score and postoperative visual acuity were analyzed. The SAC examination is a reproducible and rapid method for the comparison of the preoperative and postoperative metamorphopsia in patients undergoing pucker surgery and it may serve as an additional outcome measure.
Posted by mehdi khanlari at 10:49 PM
Artiflex IOL
OSN feb 2003
PORTO, Portugal – The Ophtec Artiflex lens offers refractive surgeons another option in foldable phakic IOLs.The new silicone lens material used in the Artiflex there is not as much endothelial concern as in the past, nor the same level of risk of cataract formation. With a small incision, however, there is no risk of astigmatism and topical anesthesia can be used, he said. Artiflex iris-fixated phakic IOL has a 6-mm optical zone, a soft silicone optic and PMMA haptics. It is the same size as the rigid Artisan.
A paracentesis is created at 10 o’clock and 2 o’clock, just as in surgery for the rigid Artisan. A spatula is used, allowing a slow, controlled entrance of the lens through a 3.2-mm incision. The lens then unfolds itself without contact with the corneal endothelium. Once it is inside, the spatula is disengaged and removed.
Posted by mehdi khanlari at 10:05 PM
February 25, 2003
Management of posterior polar cataract
JRS,Feb.2003
In this technique for managing posterior polar cataract, extreme care is taken not to overpressurize the anterior chamber or capsular bag to prevent posterior capsule rupture. Minimal hydrodissection and hydrodelineation are performed. The nucleus is extracted using minimal ultrasound energy. Viscodissection is used as a primary technique to mobilize the epinucleus and cortex. A protective layer is preserved over the posterior polar region until the conclusion of the extraction procedure to minimize the risk of loss of lens material into the vitreous cavity in the case of a capsule defect
EMKH
Posted by alireza habibollahi at 11:19 PM
Surgical Treatment of Keratoconus at the Turn of the 20th Century
JRS January/February 2003
This paper reviews surgical modalities for treatment of keratoconus at the threshold of the 20th century. All ophthalmic literature from 1895 until 1925 in English and German, available at the library of the Institute of Ophthalmology, London, United Kingdom, was studied with respect to this topic.Three thermal procedures were described; galvanocauterization with perforation, without perforation, and a non-contact application of heat to the corneal apex. Radial extension of a thermal burn to correct the minus cylinder represented a further modification. Excision of the conical area was suggested either as a lamellar dissection or as a full thickness trephination. Incision of the cone appeared to be less popular. In staged procedures, a combination of galvanocauterization, splitting of the cornea, conjunctival flap, and a subsequent optical iridectomy were applied. The treatment of keratoconus 100 years ago used refractive surgery to improve visual function by modifying corneal shape. [J Refract Surg 2001;17:69-73]
EMKH
Posted by alireza habibollahi at 10:44 PM
February 24, 2003
Effect of non-steroidal anti-inflammatory ophthalmic solution on intraocular pressure reduction by latanoprost
British Journal of Ophthalmology 2003;87:297-301
These results indicate that NSAID ophthalmic solution may interfere with IOP reduction by latanoprost ophthalmic solution in normal volunteers and that we should take this into account when treating patients with glaucoma using latanoprost ophthalmic solution.
Posted by mmiraftab at 11:59 PM
February 23, 2003
Autorefractometry after laser in situ keratomileusis
J Cataract Refract Surg 2003; 29:133–137 © 2003 ASCRS and ESCRS
To correlate cycloplegic subjective refraction with cycloplegic autorefractometry in eyes that have had laser in situ keratomileusis (LASIK),Subjective refraction and autorefractometry under cycloplegia were performed in 73 eyes of 46 patients 1, 6, and 12 months after LASIK to correct myopia or myopic astigmatism.A statistically significant difference between subjective refraction and autorefraction was found in the sphere and cylinder at all postoperative times. No statistically significant difference was found in the axis. There was no statistically significant difference in the control eyes....Retreatments after LASIK should always be based on subjective refraction.
Posted by agholami at 09:41 PM
Central and peripheral corneal thickness measurement with Orbscan II and topographical ultrasound pachymetry
J Cataract Refract Surg 2003; 29:125–132 © 2003 ASCRS and ESCRS
To compare thickness measurements of the central 6.0 mm of the cornea obtained with the Orbscan® II topography system and topographical ultrasound pachymetry, In 24 right eyes, pachymetric measurements were taken at the center and 1.2 mm and 3.0 mm on the superior and inferior hemimeridians.Orbscan II data were analyzed in 3 ways: (1) without the application of an acoustic equivalent correction factor; (2) with a correction factor of 0.92, as recommended by the manufacturer; (3) with correction using the equations derived in this study. The data were systematically compared with those of ultrasound pachymetry.
Conclusions:The acoustic equivalent correction factor proposed by the manufacturer to obtain corneal thickness measurements with the Orbscan II compared to those from ultrasound pachymetry was not valid for all corneal topography positions. Orbscan II measurements agreed better with those of ultrasound pachymetry when equations for the central and each peripheral location across the topography were applied.
Posted by agholami at 09:30 PM
February 22, 2003
Synthetic thiamine derivative could help prevent diabetic retinopathy
OSN 2003
Animal studies suggest,a synthetic derivative of thiamine (Benfotiamine, a synthetic derivative of vitamin B1, has been available for more than a decade in Germany, where it is used for the treatment of diabetic neuropathy, sciatica and other painful nerve conditions)may be effective in preventing diabetic retinopathy, . The drug blocks three of the four major biochemical pathways responsible for blood-vessel damage that causes serious diabetic complications,diabetic rats treated with benfotiamine for 36 weeks. A control group of rats with diabetes was left untreated, the rats being treated with benfotiamine had not developed any of the retinal damage seen in the non-treated group.
Posted by kjalali at 09:23 PM
February 21, 2003
NIH study: Uveitis patients sought for vitamin E study
Ophthalmology Times January 15, 2003
The National Institutes of Health (NIH) is conducting a study to evaluate whether vitamin E can help in the treatment of cystoid macular edema (CME) due to uveitis.Participants will receive a daily high dose of either vitamin E or a placebo for 4 months. Enrollment is open to patients age 9 or older with documented CME associated with uveitis.
Posted by mmiraftab at 09:52 PM
Bag-in-the-lens implantation of intraocular lenses
J Cataract Refract Surg 2002; 28:1182–1188
Report a new intraocular lens (IOL) and an IOL implantation concept, the bag-in-the-lens implantation technique, designed to prevent posterior capsule opacification (PCO).
After identical curvilinear capsulorhexes are created in both the anterior and posterior capsules, the capsules are inserted in a flange of the IOL, thus the term bag-in-the-lens as opposed to the currently used lens-in-the-bagtechnique. The IOL was implanted in an in vitro human capsular bag model and in 10 eyes of 9 patients with cataract. Lens epithelial cell (LEC) outgrowth and PCO formation were observed. When both capsular blades were well stretched around the IOL optic, the in vitro capsular bag model showed LEC proliferation only within the space of the remaining lens bag. The LEC proliferation was limited, and there was no tendency toward proliferation approaching the visual axis. In all 10 eyes, the optical axis remained clear during a follow-up between 4 and 15 months. This new IOL prevented LEC proliferation in vitro and seems promising in vivo. Target patients are those at risk of PCO including those with congenital cataract, uveitis, diabetes, or cataract extraction combined with vitrectomy.see two fiigures: 1.bmp2.bmp
Posted by mmiraftab at 04:01 PM
The Vision Membrane
Cataract & refractive surgery today,Jan 2003 
A new anterior chamber device corrects presbyopia, as well as moderate-to-severe myopia and hyperopia. The VISION MEMBRANE (VISION MEMBRANE TECHNOLOGIES, Inc., Carlsbad, CA) employs a radically new approach to correcting moderate-to-severe ametropia and presbyopia.The VISION MEMBRANE is constructed entirely of medical-grade silicone. When implanted in the anterior chamber of the eye, this thin, vaulted membrane can correct both presbyopia and refractive errors including myopia, hyperopia, and astigmatism. Unlike standard IOLs, which generally have a thickness of 700 to 1,000 µm, the VISION MEMBRANE is 200 µm thick, regardless of the dioptric power (Figure 1).
Furthermore, the foldable device’s dimensions and vaulted shape create an excellent blend of stability, flexibility, and implantability through an incision less than 2.0 mm wide (Figure 2).Compared with an IOL with a flat optic, the VISION MEMBRANE’s curved optic produces a greater amount of space between it and the delicate corneal endothelium. Unlike the 4.5-mm optic of the pioneering Baikoff IOLs (NuVita lens, Bausch & Lomb Surgical, San Dimas, CA), the optic of the VISION MEMBRANE is 6.5 mm in diameter. Also, the vaulted design of the device prevents pupillary block and thus avoids the need for a peripheral iridotomy.Another advantage of the VISION MEMBRANE is that its hydrophobic silicone material and broad haptic design prevent the formation of anterior synechiae. Angle-fixation makes implantation simpler, because it eliminates the need for excessive surgical manipulation. Due to the VISION MEMBRANE’s extreme flexibility and variable vaulting in the anterior chamber, one size of the device fits nearly all eyes, although two sizes will be available.The device also employs modern diffractive optics in order to focus incoming light, and the quality of vision that they produce is equal to that created by an IOL with refractive optics. Modern diffractive optics effectively correct ametropia, and ongoing European and US trials of pseudophakic bifocal IOLs indicate the potential advantage of diffractive over refractive optics for the correction of presbyopia. Unlike standard lenses that use refractive optics, the VISION MEMBRANE’s diffractive optics do not rely on the lens material’s index of refraction in order to gain the desired refractive effect. All patients must be 18 years of age or older with a generally stable refraction to undergo implantation of the VISION MEMBRANE. The device will be available in two forms. The first VISION MEMBRANE design is single-powered for the correction of -2.00 to -15.00 D of myopia in 0.50-D steps, and +2.00 to +6.00 D of hyperopia in 0.50-D increments. The bifocal form of the VISION MEMBRANE device is designed to correct presbyopia and either myopia or hyperopia. This version may be used in presbyopes, as well as in patients who have already received a posterior chamber IOL after cataract extraction but who have limited reading vision.Of course, the quality of results attained in patients combined with surgeon opinion will determine the success of the VISION MEMBRANE. It has been implanted in trial patients outside of the US, and further trials outside of the US will commence within the next 1 to 2 months. European and US trials may begin in 5 to 8 months.
Posted by mehdi khanlari at 10:38 AM
Innovations in Laser Cataract Extraction : INDIVIDUAL EXPERIENCES
Cataract & refractive surgery today,Jan 2003
The cataracts that Rajeeve Raut MD, of Pune, India, treats generally range in density from grade +4 to +6. His pioneering technique permits him to use laser photolysis for almost all of his cataract cases. Dr. Raut neither hydrodissects nor hydrodelineates the lens nucleus in order to avoid internally rotating it. He uses the posterior capsule to stabilize the nucleus as he drills a hole through its center with the laser/aspiration probe. Because the nucleus does not rotate, he is able to apply laser energy to the exact spot he chooses to create a nuclear pit. Next, Dr. Raut places the laser probe at the center of the pit he has created and applies energy, which shatters the nucleus into pieces that he can easily remove.
Posted by mehdi khanlari at 10:22 AM
February 20, 2003
Cataract Challenge : Absent Superior Zonules
Cataract & refractive surgery today,Feb 2003
CASE PRESENTATION
A white male patient in his early 50s presented with bilateral cataracts. Additionally, he had a history of ocular trauma to the right eye that occurred approximately 10 years prior to the formation of his cataracts when a racquetball struck the eye. The preoperative clinical examination revealed posterior subcapsular 3 to 4+ cataracts that were similar in appearance. I detected nothing abnormal about the right eye, including phacodynesis.I proceeded with cataract surgery in the patient’s right eye. Because he was fairly young and had a soft cataract, I planned to prolapse the lens out of the bag and aspirate it using NeoSoniX (Alcon Laboratories, Inc., Fort Worth, TX). For harder cataracts, I normally perform in-the-bag chopping. To begin, I created a temporal, 3-mm, clear corneal incision. As I made the capsulorhexis, I began to suspect a problem with the superior zonules. While extracting the patient’s lens, however, I noticed that all of the superior zonules were absent . Using NeoSoniX, I extracted the lens nucleus at the iris plane without incident. Removing the epinucleus and cortex, however, posed a problem because the superior portion of the capsular bag collapsed, wrinkling downward like a raisin to where it was supported by the inferior zonules.
HOW WOULD YOU PROCEED?
1. Would you attempt manual or automated I/A?
2. Would you leave or remove the remaining capsular bag?
3. Which IOL would you choose, and how would you implant it?
4. How would you prevent vitreous prolapse?
Posted by mehdi khanlari at 08:26 AM
Pirenzepine for treatment of myopia
Cataract & refractive surgery today,Feb 2003
Novartis Ophthalmics (Basel, Switzerland) recently acquired the exclusive rights to develop and market pirenzepine, a drug for the topical treatment of myopia. The drug, which was developed by Valley Forge Pharmaceuticals Inc. (Irvine, CA), is currently in the clinical trials and will be marketed by Novartis upon completion of the trials. According to the company, Phase II trials show that pirenzepine can reduce the progression of myopia by at least 50% in the first 12 months of therapy
Posted by mehdi khanlari at 08:06 AM
Refractive Challenge: Band Keratopathy Within a LASIK Flap
Cataract & refractive surgery today,Feb 2003
CASE PRESENTATION
A 37-year-old white male presented with complaints of decreased vision after a motor vehicle accident involving the deployment of an airbag in December 1999. He had undergone an uncomplicated bilateral LASIK procedure for moderate myopia in March 1999. Postoperatively, the patient had a UCVA of 20/25 OD and 20/20 OS.The fundus exam revealed a giant retinal tear with the macula off in the right eye and multiple horseshoe-shaped tears in the left eye. The patient subsequently underwent a laser retinopexy in the left eye and a scleral buckle procedure in the right eye. In May 2000, a recurrent retinal detachment of the right eye necessitated additional argon laser retinopexy. When a progressive retinal detachment occurred in the right eye later that month, a vitrectomy and lensectomy were performed and a C3F8 gas bubble placed
. One month later, the retina in his right eye redetached, so the patient underwent repeat vitrectomy, membrane peeling, and placement of silicone oil.The patient then developed rapid-onset band keratopathy within the LASIK flap of his right eye. Another ophthalmologist performed manual debridement. It is unknown whether EDTA chelation was also employed. During the next several months, the band keratopathy recurred. In October 2000, an additional surgical procedure was performed to remove more scar tissue from the retina and to fill the aphakic eye with silicone oil.
HOW WOULD YOU PROCEED?
1. Would you debride the calcific deposits from the cornea to allow for retinal surgery with a view through a debrided surface?
2. Amputate the flap, since the calcific deposits clinically appear to be limited to the flap itself and not present in the stromal bed?
3. Place a temporary keratoprosthesis in order to allow retinal surgery to proceed and complete the case as a penetrating keratoplasty?
Posted by mehdi khanlari at 07:40 AM
February 19, 2003
Sponges or compressed air can help manage corneal bleeds during LASIK
Eyeworld Feb 2003
The use of a dry sponge during ablation and an Iopidine-soaked sponge after the ablation can effectively augment a surgeon’s technique in the event of corneal bleeding during LASIK
The technique
Probst marks the corners of the flaps prior to the procedure so when the flap is repositioned good alignment of the whole inferior portion of the flap can be achieved.
For patients with a normal size cornea, he uses the 9.5-mm ring on the Hansatome. Because there are cuts through the superior vessels, he replaces the ring on the eye and uses a suction ring to attempt to tamponade the bleeding.In some cases, even with pressure of the suction ring on the eye, there still may be bleeding from the superior part of the flap. In such an instance, Probst places dry LASIK sponges on the cornea in the area where the bleeding is occurring. Alternatively, an instrument wipe can be cut up, stored in a sterile package, and be ready for use in case the need arises
Post-ablation procedure
After the ablation is complete, the flap is repositioned. A cannula is selected for use because it allows the surgeon to enter from the superior approach.When the flap is back in place there may be additional bleeding. In cases where there is bleeding from either end of the superior flap, the surgeon needs to irrigate the flap a few times.The LASIK sponges, soaked in Iopidine [apraclonidine, Alcon] are placed on the cornea, allowed to soak up all the bleeding, and then removed one minute later. It’s nice and clean there, and you’re done,” he said.
Compressed air
The use of compressed air can prevent or eradicate corneal bleeding during LASIK, said Marguerite B. McDonald. “I spot the bleed immediately after removing themicrokeratome, of course.Before lifting the flap, I use compressed air through a very small nozzle, and direct the flow onto the bleeding area. When the blood is congealed, I carefully lift the flap, ablate, and reposit the flap. The bleeding rarely starts up again. If it does, I just close the flap again, irrigate the interface again, and blow more air at the bleeding vessels. This technique is useful for all lasers, but especially for LadarVision lasers because sponges cannot be placed on the limbus during the ablation, as they will throw off the tracker. This technique also minimizes the number of times that the interface must be irrigated. Too much irrigation makes the flap less likely to adhere well to the bed and also causes the flap to be very edematous. After the edematous flap deturgesces, visually debilitating microstriae can form.”
Posted by smrtaheri at 01:57 PM
PTK offers another option for treating chronic flap striae
Ophthalmology Times February 1, 2003
Phototherapeutic keratectomy (PTK) with a broad-beam laser may be a useful treatment for eyes with chronic, visually significant post-LASIK flap microstriae.Roger F. Steinert, MD reported outcomes for a series of 19 eyes of 18 patients that were followed for a mean of 4 months (range, 1 to 12) after undergoing PTK. Overall, the procedure resulted in improved best spectacle-corrected visual acuity (BSCVA) in most eyes. Also, there was improved uncorrected visual acuity (UCVA) secondary to a slight hyperopic shift (0.87 D) with an insignificant change in cylinder (0.13 D). No eyes lost 2 or more lines of BSCVA nor developed clinically significant haze, and there were no other complications. The goal in performing PTK is to ablate the higher peaks of the striae and induce an epithelial healing response that will mask remaining surface irregularity and thereby result in improved optics of the cornea. Striae manifest as lumps and bumps in the stroma, and the epithelium responds to that irregularity in a compensatory way by growing thicker over the depressions and thinner over the elevations.However, epithelial regrowth is not sufficient to offset extremely high striae peaks completely, so we perform PTK to reduce those Rocky Mountains to foothills. The procedure is performed with a broad-beam laser (Summit Apex Plus or VISX Star S3) in PTK mode with the optical zone set for 6.5 mm. It begins with trans-epithelial PTK, ablating through the epithelium and exposing the striae peaks below regions where the epithelium is thinnest.One would think haze might be a problem because we know we should never do PRK on top of a LASIK flap,However, this PTK treatment is very superficial, never penetrating into the body of the flap, so it has not been complicated by haze.
Posted by mtmdop at 07:45 AM
Computed Tomographic Scan of a Dinosaur's Skull: The Optic Canal
Arch Ophthalmol. 2003;121:294-295
Artist's rendition of the complete skinned head of the Abelisaurus. B, Lateral view of the real Abelisaurus' skull. X-X indicates the computed tomographic scan level. C, Computed tomographic scan, coronal view. The image shows the right optic canal (large open circle) and the sella turcica (arrow). PPS indicates plaster supporting system (this support system having been built by Dr Salgado and the scan having been taken by Federico Dalla Torre, MD); JW, the dinosaur's jaw. At the bottom of the image what looks like an odd symbol is really an image artifact of a metal pin included in the PSS.
Posted by mmiraftab at 12:23 AM
Eye drops suppress immune reactions in PK patients
Eurotimes Feb 2003
FK506 eye drops appear to be an effective immunoprophylactic agent in patients undergoing penetrating keratoplasty (PK).Study indicates that the efficacy of topical FK506 is at least as high as that of topical steroids. It may well turn out to provide effective immunoprophylaxis in normal-risk keratoplasty patients.One year postoperatively all patients in the FK506 group who did not withdraw prematurely were free from immune reactions. In contrast, 84% of those receiving steroid treatment developed no immune reactions. There were no cases of irreversible graft failure in either treatment group at the one-year mark The surgical indications included keratoconus, Fuchs endothelial dystrophy, bullous keratopathy and non-herpetic scars. None of the patients had a history of severe surface disorders, glaucoma or herpetic eye disease.The researchers did not detect FK506 in whole blood samples of the patients in the FK506 group. Systemic FK506 represents one of the systemic immunosuppressive standard prophylaxes after solid organ transplantation, in combination with systemic steroids and systemic azathioprine or systemic mycophenolate mofetil. Prior research has shown topical FK506 to be highly effective in the treatment of atopic dermatitis
Posted by mehdi khanlari at 12:09 AM
February 18, 2003
Recently NIDEK introduced an ablation algorithm that specifically addresses the issue of spherical aberration.
Ophthalmology Management FEB 2003
Essentially this involves increasing the transition zone, reducing the optical zone and creating a seamless transition between the optical and transition zones and nascent cornea.Preliminary results from Paolo Vinciguerra M.D., and Arturo Chayet, M.D., on human eyes did in fact confirm that there is a reduction in the amount of induced spherical aberration. The advantages of this unique treatment method are that it actually decreases ablation volume, creates a prolate cornea, and increases the effective optical zone. By moving what Vinciguerra refers to as the "red-ring" on corneal topography past the pupillary excursion diameter and reducing the severity of contour change, the spherical aberration that would normally affect the point spread function is effectively reduced. The red ring on instantaneous (or tangential) topography often has a deep red ring after laser ablation. The severity of the color signifies abrupt dioptric power changes in the cornea between the optical zone, transition zone and nascent cornea. The diameter of the ring signifies the effective optical zone.
Read more about other wavefront systems
Posted by mmiraftab at 11:52 PM
Refractive IOLs
Eurotimes Feb 2003
Several IOL designs are now available to cataract patients who wish to leave glasses behind after cataract removal and each type of lens offers its own advantages and disadvantages .In a study comparing near visual outcomes in patients after implantation of three different types of presbyopia-correcting IOLs, those implanted with the AMO Array lens had the greatest amplitude of near vision, those with Acritec’s Twin Set IOLs had the most rapid recovery of near vision and the fewest visual side-effects such as glare and halos. Those implanted with the CrystaLens had the best quality distant vision but their near vision was less than other groups, Dr Galal said. The accommodative CrystaLens was probably the most demanding of the patient. It requires time for the patient to become educated in its use before they may comfortably alter their focus from near to distance. However, the CrystaLens induced little in the way of glare and halos and provided the best distance visual acuity and comfortable near vision. With the other two lenses such symptoms persisted for up to six months. All three lenses also have a different set of advantages and disadvantages from a surgical point of view. For example, immersion biometry is essential with the CrystaLens although ultrasound biometry is adequate for the other two lenses. The AMO lens, meanwhile, is the most ideal of the three for micro-incision cataract surgery.
Posted by mehdi khanlari at 11:16 PM
Artificial cornea promises dramatic visual recovery for unsuitable PK candidates
Eurotimes Feb 2003
An innovative artificial cornea could be a valuable new option for patients who might not otherwise be considered good candidates for penetrating keratoplasty (PK).
The AlphaCor is a soft, one-piece artificial cornea, 7.5 mm wide and 0.6 mm thick and made from poly 2-hydroxymethacrylate. AlphaCor inserted into the eye. Tissue stitched around AlphaCor to secure it in place. The device includes a clear 4.5 mm optical core surrounded by an opaque sponge skirt. The optic has a refractive power similar to the natural cornea. Versions are available in a wide range of powers for phakic, aphakic and pseudophakic patients. The AlphaCor prostheses have been implanted on an experimental basis since 1998. A review of the first 45 implants indicates that the device restored vision and was well tolerated in 41 of the 45 eyes, with an average follow-up of 15 months ranging from two to 49, Herpetic keratitis is now a contraindication for the surgery.There were no new cases of glaucoma, which has been a problem with other keratoprostheses in the past. In many cases visual recovery has been dramatic, ranging from count fingers to 20/20. No patient’s vision worsened as a result of the procedure. “We have also learned that the surgical technique we have developed is effective.Candidates for the prosthesis include those who require a corneal graft but who would be considered at high risk for graft failure. The AlphaCor is now approved for use in the US, Europe, Canada and Australia. The manufacturer, Argus Biomedical, has an international programme which provides surgical training and accreditation. A surgical training course will be offered during the Rome meeting. Surgeons will also have the opportunity to take the course at upcoming meetings of the European Society of Ophthalmology, the American Society of Cataract and Refractive Surgery and at the annual meeting of the ESCRS in September this year in Munich.
Posted by mehdi khanlari at 11:01 PM
Peripapillary detachment in pathologic myopia
Arch Ophthalmol. 2003;121:197-204
Peripapillary detachment in pathologic myopia is an asymptomatic, yellow-orange peripapillary detachment of the retinal pigment epithelium and retina in pathologic myopia. Recognition of this lesion is important to distinguish it from other fundus pathologic conditions, such as tumors or choroidal neovascularization, which require further investigation and treatment.
EMKH
Posted by kjalali at 07:54 PM
Fibrin glue versus N-butyl-2-cyanoacrylate in corneal perforations
Ophthalmology,February,2003
Fibrin glue and cyanoacrylate tissue adhesive are both effective in the closure of corneal perforations up to 3 mm in diameter. Fibrin glue provides faster healing and induces significantly less corneal vascularization, but it requires a significantly longer time for adhesive plug formation.
Posted by:Sh.Ebadollahi M.D.
Posted by afarahi at 07:27 PM
Prediction of visual outcome after penetrating keratoplasty for pseudophakic corneal edema
Ophthalmology,February,2003
Forty-eight patients who underwent 59 PKP procedures for PCE between 1997 and 2000 by two cornea specialists. Variables included age, gender, presence of diabetes or cardiovascular disease, method of intraocular lens (IOL) implantation during cataract surgery, vitreous loss during cataract surgery, time between cataract and PKP surgery, and maximal visual acuity reached after cataract surgery. Best-corrected visual acuity (BCVA) of 20/40 or better was achieved in 13 patients (27%). The strongest predictor of this outcome was implantation of a bag-fixated or sulcus-fixated IOL at the time of cataract surgery .Less significant variables included BCVA after cataract surgery, time between cataract surgery and PKP, and gender. In planning and advising patients with pseudophakic or aphakic corneal edema who are candidates for PKP, the method of IOL implantation during the cataract surgery is the single most significant predictor of visual acuity after corneal transplantation. Bag-fixated or sulcus-fixated posterior chamber IOL was associated with a better visual outcome than anterior chamber IOL, scleral-fixated posterior chamber IOL, or aphakia.
Posted by:Sh.Ebadollahi M.D.
Posted by afarahi at 07:20 PM
Optical Coherence Tomography for the Detection of Laser In Situ Keratomileusis in Donor Corneas
Cornea,January,2003
Laser in situ keratomileusis was performed on 20 organ-cultured human cornea disks. The excimer laser ablation performed ranged from 0 to 12 diopters. The corneas were maintained in culture, and the visibility of flap-stromal interface by OCT was assessed up to 6 months after the LASIK procedure. Additionally, two donor corneas with the history of LASIK treatment before death were screened for structural changes.Optical coherence tomography scans were able to detect the interface between the corneal flap and the residual stromal tissue in all corneas and at all examined time intervals. In both donor corneas with suspected prior LASIK surgery, OCT scanning showed the characteristic stromal interface as found in the in vitro model.Corneal examination by OCT could be an appropriate technique for eye banks to screen donor corneas for prior LASIK surgery.
Posted by:Sh.Ebadollahi M.D.
Posted by afarahi at 06:47 PM
February 17, 2003
RESEARCH ON NEUROPROTECTIVE GLAUCOMA TREATMENTS.
MitoKor, biotechnology company focused on commercial applications of mitochondrial medicine, received a Phase I Small Business Innovative Research (SBIR) grant from the National Eye Institute of the National Institutes of Health. MitoKor aim is to develop and commercialize neuroprotective drugs that prevent glaucoma progression. Especially targeted is glaucoma-related blindness, believed to be caused by progressive loss of retinal ganglion cells and degeneration of the optic nerve. MitoKor believes that the neuroprotective compounds, used in conjunction with IOP-lowering medications now available, will allow a more effective treatment of the disease
Posted by mmiraftab at 12:23 PM
Allergy Update
Recent studies offer new information about five frequently prescribed ocular medications.
Ophthalmology Management,FEB 2003
.This is an exciting time for both ocular allergy sufferers and ophthalmologists. In the past, most drugs used to treat allergic conjunctivitis were uncomfortable,even painful,
to use. In addition, they had to be instilled at least four times a day to maintain control of symptoms.Today, a number of potent medications without these drawbacks have been developed and brought to the market by the leading pharmaceutical companies. Thanks to increasing understanding of the pathophysiology of the allergic response in the eye, the new drugs are more potent and efficacious; many are formulated to target a specific step in the allergic cascade. At the same time, they're more comfortable to use and provide longer- lasting results. The following article summarizes five recently completed clinical studies that evaluate Alocril, Alrex, Alamast, Zaditor and Patanol.These studies demonstrate that each of these agents is safe and effective for the treatment of allergic conjunctivitis. In addition, some of the studies show that the medications are safe when used for an extended period, that they may provide unexpected benefits for the corneal and conjunctival surface, and that they may play a role in alleviating the symptoms of allergic rhinitis in addition to providing ocular relief.
What's next? Treatment of allergic conjunctivitis is moving toward immuno-modulation of the host response to disease. Therapy may target not only the mast cell and its products, but also interleukines, cytokines, T-helper lymphocytes and anti-IgE. Read more...
Posted by mmiraftab at 12:17 PM
February 15, 2003
Iatrogenic punctate chorioretinopathy after internal limiting membrane peeling
AJO,FEB 2003;178-182
To define the chorioretinal lesions created unintentionally during grasping the internal limiting membrane (ILM) with end-gripping forceps a prospective review of a consecutive series of 15 patients (15 eyes) who underwent macular hole repair was performed. All patients underwent a three-port pars plana vitrectomy with ILM peeling.In all eyes, small punctate barely seen chorioretinal lesions in the macular region were detected after surgery. These punctate lesions corresponded to the area where ILM was grasped with forceps.It must be reported as one of the complications of ILM peeling. These small punctate lesions did not appear to affect the surgical outcome. However, the lesions should be followed to detect any long-term complication such as choroidal neovascularization.
EMKH
Posted by kjalali at 06:06 AM
Trypan blue not toxic for RPE in vitro
AJO,FEB 2003;234-236
To investigate whether trypan blue has a toxic effect on cultured retinal pigment epithelial cells an experimental study with a direct live/dead cell staining technique using fluorescent dyes performed.Cultured human retinal pigment epithelium cells were exposed for 5 minutes to various concentrations of trypan blue (0.06%, 0.15%, 0.30%), and cell viability was confocally measured.No increased cell death was found in cultures incubated in any of the trypan blue concentrations used.These findings indicate that a short exposure of trypan blue does not have a toxic effect on cultured retinal pigment epithelium cells.
EMKH
Posted by kjalali at 05:54 AM
February 14, 2003
A Case of Acute Dacryoadenitis Associated with Herpes Zoster Ophthalmicus
Japanese Journal of Ophthalmology Volume 47, Issue 1, January-February 2003, Pages 107-109
Acute dacryoadenitis is a relatively rare disease, for which mumps virus, measles virus, Epstein-Barr virus, influenza virus, and bacterial infection have been listed as causes.It has been described that varicella-zoster virus can also cause acute dacryoadenitis. However, to our knowledge, there is no such case in the literature. We report, perhaps for the first time, a case of herpes zoster ophthalmicus with the onset of acute dacryoadenitis.
Figure 1. Coronal (A) and axial (B) fat-suppressed contrast-enhanced T1-weighed magnetic resonance images showing swelling and abnormal enhancement of the right lacrimal gland (arrows). (B) Abnormal enhancement also is present in the upper eyelid and anterior segment of the eye, indicative of iridocyclitis (arrow heads).
Systemic antibiotic therapy was discontinued and intravenous acyclovir (5 mg/day, 3 times a day) was begun, with the use of topical steroid and acyclovir ointment. After 4 days of treatment with acyclovir, the severe ocular pain and swelling of his upper eyelid was resolved. Intravenous acyclovir was administered for 7 days. Iridocyclitis disappeared over a 3-month period with the application of topical steroid and acyclovir ointment 4 times daily. Four months after the initial medical examination, MRI showed there was no longer enlargement of the right lacrimal gland. His visual acuity has remained 20/20; no other complications such as keratitis and glaucoma have been found during the follow-up period. So far, no dry eye syndrome has been observed in the right eye of this patien
EMKH
Posted by Ali Reza Naderi at 08:30 PM
Bilateral Iris Metastases from Prostate Cancer
Japanese Journal of Ophthalmology Volume 47, Issue 1, January-February 2003, Pages 69-71
Iris metastases of malignant tumors are not common, and most of the cases are unilateral. To our knowledge, there has been no report of bilateral iris tumors metastasized from prostate cancer.A 71-year-old man with complaints of blurred vision and pain in both eyes was referred to our eye clinic. Gray-white fleshy and multi-nodular tumors without apparent superficial vessels spread mainly in the superior portion of the iris of the right eye and in the inferior portion and superior pupillary margin in the iris of the left eye. The pupils were irregularly deformed in both eyes (Figure 1). Iridocyclitis with moderate cells and flare was found in both eyes.He had history of prostate cancer presented with bilateral iris tumors and secondary glaucoma. He had had multiple bone metastases, and had undergone chemotherapy. Gray-white fleshy tumors spread in the iris of both eyes. Iridocyclitis and secondary glaucoma were present. After external beam radiotherapy, the iris tumors regressed remarkably in volume. The tumors were well controlled with conservative therapies including radiation. We believe this article is the first report of bilateral iris tumors metastasized from prostate cancer.As the origins of uveal metastasis, breast and lung cancers are most commonly observed, with a ratio of 60% to 90% of all uveal metastasis cases reported. Prostate cancer is the predominant cause of cancer-related death and it frequently metastasizes to bone or orbit. It rarely metastasizes to the uveal tissues and represents only 2% of uveal metastatic cases 
Figure 1. Bilateral iris tumors were observed at the first visit to our clinic by a 71-year-old man with a history of prostate cancer. Left: Gray-white fleshy tumor mainly located in the superior portion of the iris in the right eye. Right: Similar tumor located in the inferior portion and superior papillary margin in the left eye. 
Figure 2. Irises 1 month after radiation therapy. Left: Right eye. Right: Left eye. The iris tumors apparently regressed in volume in both eyes.
EMKH
Posted by Ali Reza Naderi at 07:57 PM
Learning a new language: understanding the terminology of wavefront-guided ablation
OCULAR SURGERY NEWS 2/1/03
READ MORE
EMKH
Posted by Ali Reza Naderi at 04:13 PM
Questioning the need for routine bone marrow aspiration and lumbar puncture in patients with retinoblastoma
Clinical & Experimental Ophthalmology, February, 2003
This study assesses the value of routinely investigating children with retinoblastoma with bone marrow aspiration and lumbar puncture, staging investigations not without risk and trauma to the patient, emotional stress on parents and financial cost to the community.
Medical files and specimens were obtained and examined for123 patients with retinoblastoma from 1975 to 2001.
Of all 123 subjects, 112 (91.1%) had bone marrow aspiration and lumbar puncture performed during initial assessment, and none showed evidence of malignancy.
Conclusions: Given the small but significant risks associated with these procedures, the results of this study cannot support bone marrow aspiration and lumbar puncture as routine investigations in all patients presenting with retinoblastoma, suggesting a more limited usage of these investigations is warranted.
Posted by afarahi at 12:21 PM
Complex Visual Hallucinations in the Visually Impaired: The Charles Bonnet Syndrome
Sur ophthalmology Volume 48, Issue 1 (January 2003)
Visually impaired patients may experience complex visual hallucinations, a condition known as the Charles Bonnet Syndrome. Patients usually possess insight into the unreality of their visual experiences, which are commonly pleasant but may sometimes cause distress. The hallucinations consist of well-defined, organized, and clear images over which the subject has little control. It is believed that they represent release phenomena due to de-afferentation of the visual association areas of the cerebral cortex, leading to a form of phantom vision. Cognitive defects, social isolation, and sensory deprivation have also been implicated in the etiology of this condition. This condition, which is most common in the elderly, frequently goes unrecognized in clinical practice, due to both lack of awareness among doctors and patients" reluctance to admit to hallucinatory experiences, for fear of being labeled mentally unstable. Furthermore, patients who comprehend the unreality of their hallucinations may be distressed by the real fear of imminent insanity. Sensitive and sympathetic history taking is essential to ascertain the existence of hallucinations. Reassurance and explanation that the visions are benign and do not signify mental illness have a powerful therapeutic effect. Hallucinatory activity may terminate spontaneously, on improving visual function or on addressing social isolation. There is no universally effective drug treatment but anticonvulsants may play a limited role in aborting the hallucinations. Physician awareness and empathy are the cornerstones of management.
EMKH
Posted by Ali Reza Naderi at 01:36 AM
February 13, 2003
Obesity, hypertension are additional risk factors for retinopathy
Arch Ophthalmol. 2003;121:245-251
Hypertension and abdominal obesity were found to be predictors of retinopathy in a study in a general population. Screening for and subsequently treating these risk factors may help prevent retinopathy in both diabetic and nondiabetic people, the study authors suggest. Of the 233 participants, 27 developed retinopathy by the last follow-up. Of those newly diagnosed with retinopathy, 24 developed minimal nonproliferative retinopathy and one developed moderate nonproliferative retinopathy. People who developed retinopathy had a higher mean age, higher systolic blood pressure and a larger waist circumference than those who did not develop retinopathy. The cumulative incidence of retinopathy was highest for people in the 60-69 year old age range. Sex was not a significant factor. A high waist-hip ratio, but not body mass index, seemed to indicate a high risk of developing retinopathy after 10 years, independent of age, sex, HbA1c level and hypertension. Glycemia, hypertension, and abdominal obesity are determinants for retinopathy in a general population
Posted by Ali Reza Naderi at 10:15 PM
The Use of Vicryl Mesh in 200 Porous Orbital Implants: A Technique With Few Exposures
Ophthalmic plastic and reconstructive surgery,Jan,2003
187 patients with an average follow-up of 20.5 months (range, 6 to 80 months)underwent placement of a polyglactin 910 mesh-wrapped porous orbital implant.(13 patients who had less than 6 months follow -up were omitted from the study)There were 76 primary enucleations and 124 secondary orbital implants. One hundred fourteen patients (57%) underwent peg placement. The average time to pegging was 9.9 months (range, 6 to 16 months). Before pegging, 4 of 187 patients (2.1%) had implant exposure. Two patients required a temporalis fascia graft and one required a scleral patch; the remaining defect closed spontaneously. One patient had conjunctival thinning 6 months after orbital implantation, which remained stable with no frank exposure for 36 months. No patient had excess socket inflammation. After peg placement, 3 additional patients had exposure of the implant around the peg site. There were no cases of conjunctival thinning or exposure of the implant other than adjacent to the peg site.
Conclusions: Polyglactin 910 mesh is an excellent option as a wrapping material for porous orbital implants. It is simple to use, readily available, eliminates the need for donor tissue, does not require a second operative site, and it is less expensive than other currently available wrapping materials
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Posted by afarahi at 01:23 AM
Silicone nasolacrimal intubation with mitomycin-C: a prospective, randomized, double-masked study
Ophthalmology, Feb, 2003
This study was designed to evaluate the efficacy of MMC-treated SI technique in patients with an obstructed lacrimal system who were candidates for DCR or Jones tube.
Twenty-four patients (7 males, 17 females; aged 2–69 years) with 27 eyes (three bilateral cases) underwent SI with application in a randomized, double-masked fashion of MMC or placebo, with the former receiving 0.2 mg/ml MMC for 2 minutes before SI. Follow-up ranged from 13 to 23 months (mean, 18 months; median, 17 months). Seven of the 12 eyes in the MMC group and 8 of the 15 eyes in the placebo group had a successful outcome and remained symptom free. The difference was not statistically significant (P = 0.79). Dacryocystorhinostomy or Jones tube was performed in five eyes in the MMC group and in seven eyes in the placebo group 3 to 18 months later; all had successful outcome and no complications. CONCLUSIONS: Mitomycin-C application during SI did not benefit outcome. Complications from such application were mild and infrequent. . Dacryocystorhinostomy or Jones tube continued to work very well when the SI procedure with MMC failed.
Posted by afarahi at 12:55 AM
February 12, 2003
Intraocular Pressure-Induced Interlamellar Keratitis after LASIK Surgery
Journal of Glaucoma 2003; 12(1):23-26
To describe a case of interlamellar stromal keratitis induced by increased intraocular pressure (IOP) after LASIK surgery.A 53-year-old white man with a history of treated ocular hypertension underwent uncomplicated LASIK surgery. The postoperative course was complicated by markedly elevated IOP induced by topical corticosteroid drops used to treat what appeared to be diffuse lamellar keratitis. Because IOPs remained uncontrolled despite maximal therapy, topical steroids were discontinued after a total of 9 weeks. The IOP rapidly returned to normal range with complete resolution of the corneal findings. Humphrey visual field analysis, confocal scanning laser imaging of the optic nerve, and stereoscopic disc photographs all demonstrated that significant glaucomatous field loss and optic atrophy developed over this 8-week period.The IOP should be immediately evaluated in patients who present with interlamellar stromal keratitis more than 1 week after LASIK. If the IOP is elevated, corticosteroid drops should be discontinued to prevent permanent visual loss. Furthermore, if a glaucoma specialist examines a patient with a history of LASIK and unexplained visual field loss, the medical record should be reviewed to determine if the postoperative course was complicated by this diffuse lamellar keratitis-like phenomenon.
EMKH
Posted by Ali Reza Naderi at 11:44 PM
Hydroxyapatite Orbital Implant Vascularization Assessed by Magnetic Resonance Imaging
Ophthalmic Plastic and Reconstructive Surgery 2003; 19(1):46-52
This study demonstrated consistent central HA orbital implant enhancement on MR imaging in the 9- to 15-week group and the >31-week postoperative group. HA orbital implant drilling and peg placement should be performed after central vascularization of the spherical implant has occurred. The results of this study support the principle of performing orbital implant drilling and peg placement at least 5 to 6 months after HA implant insertion.
EMKH
Posted by Ali Reza Naderi at 10:51 PM
Cautery of the Orbital Septum During Blepharoplasty
Ophthalmic Plastic and Reconstructive Surgery 2003; 19(1):1-4
Application of a grid of electrocautery to the orbital septum to treat anteriorly prolapsed eyelid fat pads during blepharoplasty has been previously described. A review of patients who underwent this technique was performed to determine if this technique led to a higher incidence of postoperative eyelid retraction.A retrospective case series of patients who underwent application of a grid of electrocautery to the orbital septum during blepharoplasty from 1979 to 1999 was reviewed.There were 1492 patients (3018 eyelids) who underwent an application of a grid of electrocautery to the orbital septum during this period. Five hundred twenty-nine patients (1036 eyelids) underwent upper blepharoplasty, 91 patients (174 eyelids) underwent lower blepharoplasty, 149 patients (596 eyelids) underwent combined upper and lower blepharoplasty, and 723 patients (1212 eyelids) underwent a combined upper blepharoplasty and ptosis repair. All patients were followed for at least 3 months. Follow-up ranged from 3 months to 20 years. No patient had postoperative eyelid retraction.The application of a grid of electrocautery to the orbital septum during blepharoplasty to treat anteriorly prolapsed eyelid fat pads is effective, safe, and does not lead to late postoperative eyelid retraction.
EMKH
Posted by Ali Reza Naderi at 10:39 PM
February 11, 2003
Motion perception in glaucoma patients. A review.
Surv Ophthalmol 2003 Jan-Feb;48(1):92-106
Most of the histopathological and psychophysical studies in glaucoma reveal a preferential damage to the magnocellular (M) pathway although a few of them support a damage to the parvocellular (P) pathway as well. In glaucoma, the visual fields are usually evaluated by conventional perimetry. However, it has been demonstrated that 20-40% of ganglion cells are lost before field defects are detected using conventional perimetry. Therefore, new psychophysical tests have recently been designed in order to specifically isolate and evaluate the visual mechanisms that are impaired at the early stages of glaucoma. In this context, several authors have addressed the issue of motion perception under the hypothesis of a predominant damage of the M pathway in glaucoma, and that motion perception is mediated mainly by M pathway. The results of these studies depict a large variation in the percentage of patients showing anomalous motion perception. Overall, motion thresholds are elevated in both glaucoma and ocular hypertensive patients as compared to control subjects, irrespective of the stimulus size and eccentricity. The test which discriminates best between patients and normal subjects is motion perimetry. The visual field defects in glaucoma patients identified by conventional perimetry and motion perimetry are similar, but the sizes of the defects are usually larger with motion perimetry. However, motion tests in central vision have no correlation with visual field defect on conventional perimetry. In glaucoma, loss of performance on motion perception tests does not necessarily support the existence of a specific deficit in the M pathway, because some behavioral studies suggest that the P pathway can also mediate motion perception. It is also difficult to conclude that motion perception is specifically affected in glaucoma because most of these studies do not yield a comparison with other visual functions. Despite these difficulties, localized motion perception tests at eccentricities of more than 15 degrees can be considered as a promising diagnostic tool.
Posted by mehdi khanlari at 12:26 PM
Does Photorefractive Keratectomy Alter the Effect of Topical Medications?
Ophthalmologica 2002;216:430-433
The influence of photorefractive keratectomy (PRK) on drug penetration into the eye is not yet established, as this procedure may alter the barrier function of the cornea as well as the blood ocular barrier. Pupillary response to topical tropicamide depends on its penetration into the anterior chamber. The purpose of this study was to examine the influence of PRK on pupillary response to topical tropicamide, and hence to evaluate whether PRK alters drug penetration into the eye. A trend for greater dilation was seen in patients with myopia above 6 diopters (13.7 and 10.5% in treated and untreated eyes, respectively, p = 0.11) and cornea thinner than 540 µm (14.2 and 10.1% in treated and untreated eyes, respectively, p = 0.1). Discussion: Our results confirm animal and human studies that found restoration of the ocular drug barrier at 4 weeks following PRK. The trend for greater penetration in patients with high myopia and thin corneas warrants further study on a larger cohort of this subgroup
Posted by mmiraftab at 01:11 AM
February 09, 2003
Effect of beam size on the expected benefit of customized laser refractive surgery.
J Refract Surg 2003 Jan-Feb;19(1):15-23
Customized laser surgery attempts to correct higher order aberrations, as well as defocus and astigmatism. The success of such a procedure depends on using a laser beam that is small enough to produce fine ablation profiles needed to correct higher order aberrations. Wave aberrations were obtained from a population of 109 normal eyes and 4 keratoconic eyes using a Shack-Hartmann wavefront sensor. We considered a theoretical customized ablation in each eye, performed with beams of 0.5, 1.0, 1.5, and 2.0 mm in diameter. We then calculated the residual aberrations remaining in the eye for the different beam sizes. Retinal image quality was estimated by means of the modulation transfer function (MTF), computed from the residual aberrations. Fourier analysis was used to study spatial filtering of each beam size. The laser beam acts like a spatial filter, smoothing the finest features in the ablation profile. The quality of the correction declines steadily when the beam size increases. A beam of 2 mm is capable of correcting defocus and astigmatism. Beam diameters of 1 mm or less may effectively correct aberrations up to fifth order. CONCLUSION: Large diameter laser beams decrease the ability to correct higher order aberrations. A top-hat laser beam of 1 mm (Gaussian with FWHM of 0.76 mm) is small enough to produce a customized ablation for typical human eyes.
EMKH
Posted by Ali Reza Naderi at 04:54 AM
Proptosis after retrobulbar corticosteroid injections
Ophthalmology Volume 110, Issue 2, February 2003, Pages 443-447
Five patients who developed symptomatic unilateral proptosis after steroid injection were studied and the literature was reviewed.No previous description was found in the literature. All five cases were studied with computed tomography, and two cases were confirmed with histopathology. No fibrosis or granulomatous inflammation was identified.Orbital lipomatosis is a potential complication of retrobulbar steroid injections. Symptomatic relief can be provided by a transconjunctival approach to the lower lid fat compartment.
EMKH
Posted by Ali Reza Naderi at 04:36 AM
Photoreceptor transplantation in retinitis pigmentosa: short-term follow-up
Ophthalmology Volume 110, Issue 2, February 2003, Pages 383-391
Transplantation of adult human cadaver photoreceptor sheets harvested with the excimer laser. No immunosuppression was used postoperatively. Patients were followed for 12 months postoperatively.Best-corrected visual acuity (Bailey-Lovie chart), median reading speed, contrast sensitivity, and visual fields for the operated eye were not statistically significantly improved postoperatively. The amplitude and latency of the maculoscope electroretinogram, as well as the log threshold for dark adaptation, did not change between the operated and control (unoperated) eye. There was no detectable homograft reaction on slit-lamp biomicroscopy or fluorescein angiography. The only adverse effect observed was one patient who complained of monocular diplopia after retinal transplantation and subsequent cataract surgery.Allogeneic adult human photoreceptor transplantation is feasible in RP but was not associated with rescue of central vision or a delay in visual loss. However, any possible slowing in the rate of retinal degeneration will take many years to determine.
Posted by Ali Reza Naderi at 04:24 AM
Risk factors and prognosis for corneal ectasia after LASIK
Ophthalmology Volume 110, Issue 2, February 2003, Pages 267-275
Significant risk factors for the development of ectasia after LASIK include high myopia, forme fruste keratoconus, and low RSB. All patients had at least one risk factor other than high myopia, and significant differences remained even when controlling for myopia. Multiple enhancements were common among affected cases, but their causative role remains unknown. We did not identify any patients who developed ectasia without recognizable preoperative risk factors.
EMKH
Posted by Ali Reza Naderi at 04:13 AM
*The Implantable Contact Lens in Treatment of Myopia (ITM) Study Group
Ophthalmology Volume 110, Issue 2, February 2003, Pages 255-266
To assess the safety and efficacy of the Implantable Contact Lens (ICL) to treat moderate to high myopia.Five hundred twenty-three eyes of 291 patients with between 3 and 20.0 diopters (D) of myopia participating in the U. S. Food and Drug Administration clinical trial of the ICL for myopia.Twelve months postoperatively, 60.1% of patients had a visual acuity of 20/20 or better, and 92.5% had an uncorrected visual acuity of 20/40 or better. Patients averaged a 10.31-line improvement in UCVA, 61.6% of patients were within 0.5 D, and 84.7% were within 1.0 D of predicted refraction. Only one case (0.2%) lost > 2 lines of BSCVA. Gains of 2 or more lines of BSCVA occurred in 55 cases (11.8%) at 6 months and 41 cases (9.6%) at 1 year after ICL surgery. Early and largely asymptomatic, presumably surgically induced anterior subcapsular (AS) opacities were seen in 11 cases (2.1%); an additional early AS opacity (0.2%) was seen because of inadvertent anterior chamber irrigation of preservative-containing solution at surgery. Two (0.4%) late ( 1 year postoperatively) AS opacities were observed. Two (0.4%) ICL removals with cataract extraction and intraocular lens implantation have been performed. Patient satisfaction (very/extremely satisfied) was reported by 92.4% of subjects on the subjective questionnaire; only four patients (1.0%) reported dissatisfaction. Slightly more patients reported an improvement at 1 year over baseline values for the following subjective symptoms: quality of vision, glare, double vision, and night driving difficulties. Only a 3% difference between pre-ICL and post-ICL surgery was reported for haloes.
The results support the safety, efficacy, and predictability of ICL implantation to treat moderate to high myopia.
Posted by Ali Reza Naderi at 04:02 AM
February 08, 2003
Topical serum application an effective therapy for bleb oozing
Ophthalmology Times January 15, 2003
Orlando-Topical application of autologous serum 20% is effective for fortifying the bleb wall and stopping aqueous oozing, but cessation of the oozing may be associated with an increase in IOP, we believe a good indication for autologous serum application would be in eyes with oozing that are either hypotonous or have IOP controlled at a level sufficiently lower than the target pressure. Point-leak is defined as a Seidel positive leak with visible streams. Such oozing or transconjunctival aqueous egress is usually observed after 10 to 12 seconds of observation with cobalt lamp illumination.The autologous serum treatment had a significant benefit for stopping oozing, but not point-leak. Point-leak is the one of the most important risk factors for bleb-related complications. Methods described to date for its management include surgical repair, subconjunctival injection of autologous blood, and application of tissue glues. On the other hand, oozing has been reported as possibly progressing to point-leak. Since oozing indicates there is damage to the conjunctival epithelium and stroma, it might be expected to be associated with impaired barrier function against bacteria. There are no established methods for treating oozing,Interest in evaluating autologous serum relates to the concept that the nutritive components and chemical mediators it contains might act to fortify the bleb wall. Used at a concentration of 20%, it has been shown effective in the treatment of a variety of chronic corneal diseases, including severe dry eye, persistent corneal epithelial defects, and superior limbic keratoconjunctivitis,
Preparation of autologous serum
The autologous serum used in the study was prepared by centrifuging 40 ml of venous blood at 1,500 rpm for 5 minutes, followed by aseptic separation of the serum and its dilution to 20% with physiological saline.
Posted by mehdi khanlari at 11:00 PM
Severity of dry eye linked to ablation depth, not flap size
Ophthalmology times,Jan,2003
Fullerton, CA-An analysis of tear film function after LASIK and LASEK indicates patients fared equally in the two groups when LASEK was performed for high myopia.Tear film dysfunction seems to be best correlated to the depth of the ablation and not flap dimension, according to Robert Lingua, MD. Dr. Lingua and colleagues found the depth of the flap to be a relevant factor. "We found clinical significance not only for the flap pachymetry measurement but also the percent thickness of the total pachymetry measurement that the flap accounted for.This suggested that a deeper initial depth at the start of the ablation likely resulted in greater tear film compromise.However, the factor that correlated best with the severity of SPK was the mean refractive spherical equivalent (MRSE). The MRSE is an indicator of ablation depth. The higher the refractive error, the more tissue ablated. It is reasonable to assume that the deeper the ablation, the more compromised are the nerve fibers and the more recalcitrant the dry eye condition.
Posted by mehdi khanlari at 10:14 PM
Trehalose eye drops found effective for dry eye syndrome
Ophthalmology Times January 15, 2003
Okayama City, Japan-Trehalose eye drops seem to be a safe and effective treatment for dry eye syndrome, based on the results of an initial clinical trial of the drug. "Trehalose is a key element in some organisms that allows them to survive under complete dehydration, called anhydrobiosis.Gene transfer of trehalose enzymes into human fibroblasts has been shown to promote desiccation tolerance.In a previous study that we conducted, trehalose prevented human corneal endothelial cells in culture from dying under desiccation when the trehalose concentrations were 100 and 200 mmol.Trehalose eye drops significantly improved signs of dry eye, especially in SjÖgren's-type dry eye, which is the severe form of the disease.The lower concentration was more effective because it was effective in patients with and without SjÖgren's-type dry eye.
Posted by mehdi khanlari at 12:03 AM
February 07, 2003
Therapeutic regimen for LASIK helps reduce complications
Ophthalmology Times January 15, 2003
Kerry Solomon, MD
Antibiotics, artificial tears control inflammation and infection, provide intensive lubrication
Posted by mehdi khanlari at 11:54 PM
Phototherapeutic Keratectomy With Mitomycin C for Corneal Haze Following Photorefractive Keratectomy for Myopia
JOURNAL OF REFRACTIVE SURGERY Vol. 19 No. 1 January/February 2003
To evaluate the safety and efficacy of phototherapeutic keratectomy (PTK) with single application of mitomycin C for patients with severe corneal haze following photorefractive keratectomy (PRK) for high myopia. Eight eyes of seven patients were treated with PTK and intraoperative topical application of mitomycin C (0.02%) for severe corneal haze (grade 3) following PRK for myopia. All patients’ visual performance improved significantly. Mean preoperative visual acuity (20/200 for both UCVA and BSCVA) improved significantly to 20/33 (0.6) and 20/30 (0.7) for UCVA and BSCVA, respectively. Six eyes (85.7%) had improved UCVA to 20/40 or better and gained five or more lines of UCVA. The corneal haze score decreased from grade 3 initially (for all eyes prior to PTK and mitomycin C) to a final mean haze score of 0.3 (range 0 to 0.5). Mean final spherical equivalent refraction achieved was -1.30 ± 1.60 D (range -3.75 to +1.25 D). One eye gained only three lines of visual acuity due to regression and residual haze. No adverse effects related to the use of mitomycin C were recorded. PTK with a single intraoperative application of mitomycin C was safe and effective in reducing corneal haze and improving visual acuity in patients with severe corneal haze following PRK. [J Refract Surg 2003;19:40-43]
Posted by Ali Reza Naderi at 09:30 PM
Femtosecond Laser Flap Creation for Laser in situ Keratomileusis: Six-month Follow-up of Initial U.S. Clinical Series
JOURNAL OF REFRACTIVE SURGERY Vol. 19 No. 1 January/February 2003
A prospective, consecutive series of 208 eyes (122 patients) undergoing LASIK between June 2000 and November 2000 using a femtosecond laser for creation of the corneal flap were evaluated for the incidence of complications. A subset of 114 patients who underwent myopic procedures and who were followed for 6 months was analyzed using standard outcome measures. In 4 of 208 eyes (1.9%), suction was lost during the procedure, causing the flap resection to be interrupted. However, in all four of these eyes the procedure was successfully performed 5 to 45 minutes after re-applanation of the eye. No postoperative complications or adverse events were observed in any treated eye. In the subgroup of 96 eyes undergoing plano correction and followed for 6 months (preoperative spherical equivalent refraction range -0.63 to -12.40 D), 98% (94 eyes) achieved uncorrected visual acuity of 20/40 or better; 94% (90 eyes) achieved 20/30 or better, 79% (76 eyes) achieved 20/25; and 55% (53 eyes) achieved 20/20 or better—all without benefit of retreatment. Femtosecond laser corneal flap creation is a safe and effective alternative to traditional mechanical microkeratomes. Standard LASIK nomograms appeared to apply equally well to the all-laser LASIK procedures. The potential for improved flap safety, reproducibility, flexibility, as well as for additional corneal applications are now being explored
Posted by Ali Reza Naderi at 09:19 PM
February 06, 2003
Risk Factors for Amblyopia in Congenital Anterior Lens Opacities
Purpose: To identify the features of congenital anterior lens opacities (CALO) which put the child at increased risk for amblyopia.
Methods: Retrospective study of 59 patients with CALO from 3 clinical practices. The following variables were examined: Type (polar, subcapsular, or pyramidal), location (central, paracentral, or peripheral), diameter, presence of adherent iris tissue, anisometropia (spherical equivalent), unilateral versus bilateral, and whether amblyopia was present. Pearson chi-square and independent sample t-tests were conducted to evaluate if any of the above variables were independently associated with amblyopia. Relative risk was then calculated for significantly related variables (p<.05).
Results: Amblyopia was present in 17 of 59 patients (28.8%). The only variables found to be associated with amblyopia was anisometropia and size of the cataract. The patients with amblyopia had a mean anisometropia of 1.23 diopters while non-ambyopic patients had a mean anisometropia of 0.25 (p=.023). The relative risk for amblyopia with anisometropia of one diopter or greater was 6.5 (95%CI=3.79-7.45). The mean cataract size in the amblyopic eyes was 1.22 mm (range 0.7- 2.0 mm). Mean cataract size in the non-amblyopic eyes was 0.96 mm (range 0.5 - 2.0 mm). This difference in mean cataract size was significant with independent sample t-tests (p=0.02), however this did not remain significant with logistic regression. Cataract size was not a significant relative risk factor for amblyopia.
Conclusions: Our overall incidence of amblyopia of 28.8% is consistent with what has been reported in previous studies1.The only variable associated with increased relative risk for amblyopia in this group of patients was anisometropia. Patients with CALO who have anisometropia of 1 diopter or greater are 6.5 times more likely to develop amblyopia
Posted by mmiraftab at 05:37 PM
Successful Treatment of Amblyopia Diagnosed Initially After the Age of Seven Years
Eighteen children from seven to ten years (range 7.02 to 9.83 years; mean 8.49 years) at initiation of amblyopia therapy for anisometropic (six patients, mean of 8.61 years), strabismic (six patients, mean of 8.10 years), or combined (six patients, mean of 8.76 years) amblyopia were seen within a pediatric ophthalmology practice following routine screening at school or in pediatric clinics. None of these children had undergone an ophthalmologic examination previously, thus, they never had worn glasses, received amblyopia therapy, or undergone strabismus surgery. The initial (worst) visual acuity was between 20/50 and 20/400. All eighteen patients had significant improvement after amblyopia therapy. Each was compliant with therapy which consisted initially of total penalization (two patients, mean of 7.93 years),full-time occluder contact lenses (seven patients, mean of 9.03 years), or full-time standard occlusion (nine patients, mean of 8.20 years). The final (best) visual acuity was between 2020 and 20/30.
Discussion: Strabismic and anisometropic amblyopia can be treated successfully if therapy is initiated before the age of ten years if compliance is achieved.
It is important to dispel the currently held view that, after the age of seven years, previously untreated amblyopia cannot be improved.
Posted by mmiraftab at 05:19 PM
LASIK SEASONALITY
Ophthalmology Management Jan 2003
There's a seasonality to this business, just like every other business," says Dr. Whitten, who observes a decline in refractive surgery in September and October in his practice. "You need to know where the peaks and valleys are so you can plan ahead and you won't feel disappointed or think something's wrong
Posted by mmiraftab at 04:57 PM
Two cases of a penetrating keratoplasty with tissue from a donor who had undergone lasik surgery
AJO Feb 2003
The authors of the first paper report on two patients who underwent penetrating keratoplasties, receiving donor corneas from eyes that had previous laser-assisted in situ keratomileusis (LASIK) surgery. Two different corneal surgeons performed the keratoplasties and were unaware that the donor corneas had prior LASIK. The penetrating keratoplasties were completed without complication in both patients, although a separation of the corneal lamellae was noted during surgery in one of the cases. The two patients were reported to be doing well 5.5 months after surgery. Long-term follow-up of patients who have penetrating keratoplasty from donors that have LASIK will reveal whether surgical success is compromised by prior refractive surgery in the donor. The authors of the second paper report the use of donor tissue from a cornea that had LASIK for an 86-year-old woman with scarring after penetrating keratoplasty. Healed LASIK flaps were noted in the donor tissue at slit-lamp examination. The recipient had informed consent. There were no intraoperative complications. In this case, the healed LASIK flap in the donor was visible by slit-lamp examination of the whole globes and after placement in storage media. Concerns of using a cornea status post LASIK as a donor for penetrating keratoplasty include centration of the ablated zone, uncertainty of refractive outcome, and weakened structural integrity
Posted by mehdi khanlari at 06:16 AM
February 05, 2003
Symptomatic Management of Postoperative Bullous Keratopathy With Nonpreserved Human Amniotic Membrane
Cornea,May,2002
A A prospective, comparative, nonrandomized management of symptomatic PBK was done by performing a complete corneal de-epithelialization followed by a NP-AMT transplantation (NP-AMT group) or no NP-AMT transplantation (control group). In the NP-AMT group, mean follow-up time was 40 weeks. Mean re-epithelialization time was 11.2 days. Symptoms of PBK resolved completely in eight patients (88%), who were asymptomatic and showing very quiet eyes from postoperative day 1.In the control group, mean follow-up time was 18 weeks; there were recurrences of symptomatic bullae in four of five patients at a mean time of 6.3 days. NP-AMT is a good alternative for the management of painful PBK in eyes with poor visual potential; NP-AMT is widely available, the technique is easy to perform, and it has good results from both the symptomatic and esthetic standpoint.
Posted by afarahi at 01:08 AM
Treatment of Advanced Acanthamoeba Keratitis With Deep Lamellar Keratectomy and Conjunctival Flap
Cornea,October,2002
Two patients (three eyes) had at least a 4-week history of painful keratitis misdiagnosed as herpetic keratitis and bacterial keratitis. Both patients were started on multiple topical antiamoebic drugs after Acanthamoeba infection was confirmed. No improvement was observed after 3-4 weeks. Surgery was then performed. Peribulbar anesthesia was given, and the infected tissue was removed by deep lamellar keratectomy. A bipediculate conjunctival flap was put in place and secured with interrupted 10-0 nylon sutures.Both patients experienced immediate pain relief. The infection was controlled and all medications were tapered. Deep lamellar keratectomy with a conjunctival flap is a suitable approach to help control the infection and to help relieve pain in patients with advanced Acanthamoeba keratitis.
Posted by Sh.Ebadollahi.M.D
Posted by afarahi at 12:09 AM
February 04, 2003
Polymer Refilling of Presbyopic Human Lenses In Vitro Restores the Ability to Undergo Accommodative Changes
Investigative Ophthalmology and Visual Science. 2003;44:250-257
Because presbyopia is thought to be accompanied by increased lens sclerosis this study was conducted to investigate whether refilling the capsule of the presbyopic human lens with a soft polymer would restore the ability of the lens to undergo accommodative changes. Accommodative forces were applied to natural and refilled lenses by circumferential stretching through the ciliary body and zonular complex. Nine natural lenses and 10 refilled lenses from donors ranging in age from 17 to 60 years were studied. Two refill polymers with a different Young’s modulus were used. The lens power was measured by a scanning laser ray-tracing technique, and lens diameter and lens thickness were measured simultaneously while the tension on the zonules was increased stepwise by outward pull on the ciliary body. In the natural lenses the older lenses were not able to undergo power changes with stretching of the ciliary body, whereas in the refilled lenses, all lenses showed power changes comparable to young, natural lenses. The refilled human lenses had a higher lens power than the age-matched natural lenses. The Young’s modulus of the polymers influenced the lens power change when measured with the ciliary body diameter increased by 4 mm.
CONCLUSIONS. Refilling presbyopic lenses with a soft polymer enabled restoration of lens power changes with mechanical stretching. Because sclerosis of the lens is an important factor in human presbyopia, refilling the lens during lens surgery for cataract could enable restoration of clear vision and accommodation in human presbyopia.
Posted by mmiraftab at 10:55 PM
Analysis of the keratocyte apoptosis, keratocyte proliferation, and myofibroblast transformation responses after photorefractive keratectomy and laser in situ keratomileusis.
Trans Am Ophthalmol Soc 2002;100:411-33
To test the hypothesis that (1) there are quantitative differences in the cellular responses in the corneal stroma after photorefractive keratectomy (PRK) for low myopia compared to high myopia and (2) there are both qualitative and quantitative differences in the cellular responses in the corneal stroma after PRK for high myopia and laser in situ keratomileusis (LASIK) for high myopia. PRK for low myopia (-4.5 diopters [D]), PRK for high myopia (-9.0 D), and LASIK for high myopia (-9.0 D) were performed in rabbit eyes, and corneas were obtained for examination at 4, 24, and 72 hours, 1 and 4 weeks, and 3 months after surgery. Stromal apoptosis, necrosis, mitosis, myofibroblast generation, and inflammatory cell infiltration were evaluated by immunohistochemical methods and electron microscopy. Keratocyte apoptosis/necrosis and the subsequent proliferation and density of myofibroblasts were qualitatively and quantitatively different in PRK for high myopia compared to either PRK for low myopia or LASIK for high myopia. Significant inflammatory cell infiltration was noted in both PRK and LASIK but appeared to be greater in PRK for high myopia. The qualitative and quantitative differences in the cellular wound healing response after PRK for high and low myopia and LASIK for high myopia are likely determinants of the clinical differences in refractive outcome and some of the complications, such as regression and haze, seen after these procedures.
Posted by Ali Reza Naderi at 09:41 AM
Long-term analysis of LASIK for the correction of refractive errors after penetrating keratoplasty.
Trans Am Ophthalmol Soc 2002;100:143-50; discussion 150-2
A retrospective review was done of 57 eyes of 48 patients with anisometropia or high astigmatism who were unable to wear glasses or a contact lens after penetrating keratoplasty and who underwent LASIK for visual rehabilitation. Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BCVA), and corneal transplant integrity were recorded before surgery as well as up to 60 months after LASIK. The mean follow-up after the LASIK was 21.4 +/- 14.2 months (range, 3-60 months). Mean preoperative spherical equivalent (SE) was -4.19 +/- 3.38 diopters (D). Mean preoperative astigmatism was 4.67 +/- 2.18 D. Preoperative BCVA was 20/40 or better in 42 eyes (74%). At 2 years the mean SE was -0.61 +/- 1.81 D and mean astigmatism was 1.94 +/- 1.35 D for the 28 eyes with follow-up. UCVA was 20/40 or better in 12 eyes (43%), and BCVA was 20/40 or better in 24 eyes (86%) at 2 years. A gain in BCVA of one line or more was seen in eight eyes (29%). Two eyes (7%) had loss of two or more lines of BCVA at 2 years. Nine eyes (16%) developed epithelial ingrowth. Five eyes (9%) in this series had repeat corneal transplants. LASIK is effective for reducing ametropia after penetrating keratoplasty. Proper patient counseling is necessary because the results of LASIK after penetrating keratoplasty are not as good as, and complications are more frequent than, in eyes with naturally occurring myopia and astigmatism. Complications are especially common in patients with mismatch of the donor and host cornea and in those with poor endothelial cell function.
Posted by Ali Reza Naderi at 09:34 AM
Refractive lens exchange with a multifocal intraocular lens.
Curr Opin Ophthalmol 2003 Feb;14(1):24-30
Refractive lens exchange with a multifocal intraocular lens is becoming a more popular method of refractive surgery in the presbyopic patient. The limitations of keratorefractive surgery have led to a resurgence of lens exchange surgery for patients with prescriptions outside the limits of corneal refractive procedures, in addition to patients with routine refractive errors requesting a surgical procedure to achieve emmetropia and also address presbyopia. Side effects of multifocal technology including unwanted photic phenomena and deterioration in contrast sensitivity are being further defined and evaluated to better assess the effects of these intraocular lenses on functional vision and patient satisfaction. Attention to detail in regards to proper patient selection, preoperative measurements, intraoperative technique, and postoperative management will ultimately result in excellent outcomes and improved patient acceptance of this effective technique.
Posted by Ali Reza Naderi at 09:27 AM
correlation between posterior corneal ectasia and ablated tissue has been established, but more work is needed.
OCULAR SURGERY NEWS 2/1/03
In keratoconus, the first part of the cornea affected is the posterior face, not the anterior face. We made graphs to show the relationship between the number of diopters taken away, because more diopters corrected signifies more ablation of tissue. We found that the amount of the ablated tissue is effectively related to the corrected diopters.” The prospective study included 112 eyes of 61 patients. The corneas were observed using the Orbscan II (Bausch & Lomb) corneal topographer. The amount of refractive correction ranged from 4 D to –12 D. “We have made three hypotheses.First, 3 months after the procedure, reliable results may not be possible with the Orbscan topographer because it is an optical device. After LASIK or LASEK procedures, the cornea isn’t as transparent as in the preoperative phase. Second, we can induce iatrogenic keratoconus, but clinically this is not important because it’s stable. Third, we can make the cornea thinner, but this cornea is unstable and within a few years we have an iatrogenic clinically serious keratoconus.the amount of the posterior keratectasia correlates to the amount of the residual bed thickness. Despite the presence of a greater residual corneal bed thickness in LASEK, the amount of keratectasia is no less important than in the LASIK cases,. “If we compare the posterior ectasia, we also find if you correct a lot of diopters, the bulging is more significant than if you correct a little myopia.Looking at the graphs for LASIK and LASEK, there isn’t a big difference between the two. The posterior ectasia is proportional to the refractive correction for LASIK and LASEK. It’s also proportional to the thickness of the residual cornea. Also, with LASEK we leave more tissue in place and we don’t have a flap. We concluded there are factors that are important for the postop corneal structure and there are important biomechanical factors. For example, we take away the Bowman’s membrane, which stabilizes the cornea. “The most important lesson is that posterior ectasia is here,. “We can photograph and calculate it, and it’s directly proportional to the refractive error correction. If we correct more than –5 D, we must analyze the thickness and the posterior face of the cornea with great attention.
“Now we are trying to collect the data after 1 year for two reasons. First, we have a more transparent cornea and the results of an optical device are more reliable. The second is to follow up whether this ectasia is progressive or not.”
Posted by Ali Reza Naderi at 09:10 AM
Can Changes in Clinical Practice Decrease the Incidence of Severe Retinopathy of Prematurity in Very Low Birth Weight Infants?
Pediatrics, Feb, 2003
A wide variability in the incidence of severe retinopathy of prematurity (ROP) is reported by different centers. The altered regulation of vascular endothelial growth factor from repeated episodes of hyperoxia and hypoxia is 1 important factor in the pathogenesis of ROP. The main objectives of this study were to monitor oxygenation levels more precisely and to avoid hyperoxia and repeated episodes of hypoxia-hyperoxia in very low birth weight infants. ROP data from January 1997 to December 2002 for infants of 500 to 1500 g were analyzed as usual The incidence of ROP 3 to 4 decreased consistently in a 5-year period from 12.5% in 1997 to 2.5% in 2001. The need for ROP laser treatment decreased from 4.5% in 1997 to 0% in the last 3 years. Conclusion. We observed a significant decrease in the rate of severe ROP in very low birth weight infants in association with an educational program provided to all NICU staff and the implementation and enforcement of clinical practices of O2 management and monitoring. Although several confounders cannot be excluded, it is likely that differences in these clinical practices may be, at least in part, responsible for the documented intercenter variability in rates of ROP.
Posted by afarahi at 01:11 AM
Minimally invasive orbital decompression for Graves’ophthalmopathy
Ann Otol Rhinol Laryngol , Jan, 2003
We reviewed a 7-year experience at a tertiary-care, academic medical center with balanced, minimally invasive decompression for Graves’ ophthalmopathy, in an effort to define the goals, risks, and outcomes of surgical intervention. Endoscopic medial decompression was performed in 26 patients; 23 underwent lateral decompression as well, and 13 also had inferior decompression.The exophthalmos improved by amean of 4.4 mm (p < .001). All patients who had surgery for threatened vision had improved vision after the operation.
Modern methods of orbital decompression provide a minimally invasive, effective, and relatively safe approach to the treatment of Graves’ ophthalmopathy.
Posted by afarahi at 12:27 AM
Dry eye and allergy symptoms seem similar but treatments differ
Eye world , Feb, 2003
The similar signs and symptoms of allergy and dry eye can lead to difficulties in diagnosis and delay in implementation of appropriate therapy. To confuse matters further, ocular allergy and dry eye can occur together and exacerbate each other. Itching is the hallmark symptom of allergy, whereas dry eye sufferers most often complain of a burning or foreign body sensation. The most effective means of treating topical diseases such as dry eye and/or ocular allergy is to first, choose topical medications and second, choose medications that have both an antihistamine and mast cell stabilizing component. Although artificial tears may help allergy, simply by acting as a barrier and diluent against allergen, anti-allergy drops, such as Alrex, Alamast, and the forthcoming once-a-day formulation of Patanol, which contain glycerin and/or povidone to lubricate and improve comfort of the eye, are much more effective.One often used option for allergy treatment is oral antihistamines, but these can have significant ocular drying effects, decreasing tear flow and volume by over 50%, even in nondry eye patients. The more potent mast cell stabilization, the more effectively an allergic reaction can be prevented and inflammation regulated.Agents that can best achieve this are the dual action compounds olopatadine (Patanol), ketotifen (Zaditor), and azelastine (Optivar).Treatments for dry eye and allergy can complement each other. Use of a comfortable dual-action eye drop for allergy symptoms can also alleviate some dryness. Allergy eye drops reduce hyperemia, which would benefit dry eye patients, as well, as chronic redness is often a complaint of those with dry eye.
Posted by afarahi at 12:06 AM
February 03, 2003
Ocular Changes in Pregnancy.
Obstet Gynecol Surv 2003 Feb;58(2):137-144
Visual changes in pregnancy are common, and many are specifically associated with the pregnancy itself. Serous retinal detachments and blindness occur more frequently during preeclampsia and often subside postpartum. Pregnant women are at increased risk for the progression of preexisting proliferative diabetic retinopathy, and diabetic women should see an ophthalmologist before pregnancy or early in the first trimester. The results of refractive eye surgery before, during, or immediately after pregnancy are unpredictable, and refractive surgery should be postponed until there is a stable postpartum refraction. A decreased tolerance to contact lenses also is common during pregnancy; therefore, it is advisable to fit contact lenses postpartum. Furthermore, pregnancy is associated with a decreased intraocular pressure in healthy eyes, and the effects of glaucoma medications on the fetus and breast-fed infant are largely unknown.
Posted by Ali Reza Naderi at 06:27 AM
Macular pucker removal with and without internal limiting membrane peeling
Ophthalmology (2003) 110: 62-64
To investigate results of macular pucker surgery with and without internal limiting membrane (ILM) peeling a retrospective noncomparative interventional study designed(case series).Forty-four consecutive patients underwent pars plana vitrectomy to remove an idiopathic macular pucker with(20 patients) and without(24 patients) ILM peeling.Visual acuity improved or was unchanged in 79% of operated eyes without ILM peeling and 100% of operated eyes with ILM peeling (P = 0.01). Visual acuity improved 5 or more lines in 25% of operated eyes without ILM peeling and 30% of operated eyes with ILM peeling. At the final visit, 21% of eyes without ILM peeling at the initial surgery showed postoperative recurrent macular pucker or persistent contraction to the ILM, whereas none of the eyes with ILM peeling had evidence of this.This pilot study provides evidence that peeling of the ILM during macular pucker surgery may not have deleterious effects.
Posted by kjalali at 06:21 AM
Diffuse Lamellar Keratitis 6 Months After Uneventful Laser in situ Keratomileusis
JOURNAL OF REFRACTIVE SURGERY Vol. 19 No. 1 January/February 2003
Diffuse lamellar keratitis after laser in situ keratomileusis (LASIK) typically occurs between 1 and 7 days after the procedure, and its etiologic factor(s) remain unknown.
We describe a case of diffuse lamellar keratitis 6 months after uneventful LASIK in a 25-year-old woman. Slit-lamp microscopy showed a diffuse infiltrate confined to the interface, extending to the visual axis, with no other relevant findings. Late on-set diffuse lamellar keratitis was our provisional diagnosis and treatment with topical corticosteroids was instituted, with rapid response and improvement of the clinical signs and symptoms. This case supports the theory that a previously inert inciting agent could cause a delayed toxic or inflammatory response of the cornea several months after surgery.
Posted by mmiraftab at 12:50 AM
Anterior Lamellar Keratoplasty With a Microkeratome: A Method for Managing Complications After Refractive Surgery
JOURNAL OF REFRACTIVE SURGERy Vol. 19 No. 1 January/February 2003
We report a noncomparative series of ten eyes with complications after LASIK and PRK. Lamellar cuts were performed in donor and recipient eyes by means of an automated microkeratome. Lamellar grafts were fixed by only four single sutures. In two eyes, a re-lift LASIK was performed after 6 months. Surgery was uneventful and visual acuity was improved in all eyes. Residual irregular astigmatism and refractive error were corrected in two eyes by means of excimer laser computer-assisted ablation and resulted in a further improvement of uncorrected and best spectacle-corrected visual acuity.
Anterior lamellar keratoplasty with a microkeratome can be used for the management of certain complications of PRK and LASIK.
Posted by mmiraftab at 12:44 AM
Equation for Corneal Asphericity After Corneal Refractive Surgery
JOURNAL OF REFRACTIVE SURGERY Vol. 19 No. 1 January/February 2003
The final p'-factor is given by p'=p(R'3/R3);R' is the final radius of curvature; R is the preoperative radius; and p is the preoperative p'-factor.
Posted by mmiraftab at 12:41 AM
Relation of ectasia and correction needs more study
OCULAR SURGERY NEWS 2/1/03
According to Dr. Simona, the amount of the posterior keratectasia correlates to the amount of the residual bed thickness. Despite the presence of a greater residual corneal bed thickness in LASEK, the amount of keratectasia is no less important than in the LASIK cases, he said.
“If we compare the posterior ectasia, we also find if you correct a lot of diopters, the bulging is more significant than if you correct a little myopia,” he said. “Looking at the graphs for LASIK and LASEK, there isn’t a big difference between the two. The posterior ectasia is proportional to the refractive correction for LASIK and LASEK. It’s also proportional to the thickness of the residual cornea. Also, with LASEK we leave more tissue in place and we don’t have a flap. We concluded there are factors that are important for the postop corneal structure and there are important biomechanical factors. For example, we take away the Bowman’s membrane, which stabilizes the cornea.” “The most important lesson is that posterior ectasia is here,” he said. “We can photograph and calculate it, and it’s directly proportional to the refractive error correction. If we correct more than –5 D, we must analyze the thickness and the posterior face of the cornea with great attention.
Posted by mmiraftab at 12:25 AM
February 02, 2003
Glue to supplement or eliminate sutures in corneal surgery
Eyeworld Feb 2003
Duke University research team is investigating a novel class of light-activated adhesives that someday may seal corneal injuries and incisions more easily and effectively than sutures or conventional adhesives.The clear, pink, paste-like glue is applied with a spatula to the surface of the wound. An argon laser beam is applied to the glue, which contains a photoinitiator, causing the adhesive to polymerize. The chemical structure of the glue differs significantly from that of conventional adhesives. Tree-shaped polymers in the new glue offer better adhesion than the linear polymers in conventional cyanoacrylate adhesives
Posted by M Khanlari MD
Posted by mehdi khanlari at 11:50 PM
Confocal Microscopy in Late-Onset Diffuse Lamellar Keratitis After Laser In Situ Keratomileusis
OPHTHALMIC SURGERY, LASERS AND IMAGING Vol. 34 No. 1 January/February 2003
This article reports a case of diffuse lamellar keratitis, without exposure of the flap interface, that developed in a patient who underwent intraepithelial photorefractive keratectomy 1 year after bilateral LASIK. Confocal microscopy was performed in both eyes at the onset of the diffuse lamellar keratitis and after its resolution. In the eye with diffuse lamellar keratitis, abundant round structures (inflammatory cells) were present at the interface; these structures disappeared after the keratitis resolved and were not present in the contralateral eye at any time. These confocal microscopic findings further support the hypothesis that diffuse lamellar keratitis is a nonspecific inflammatory response in corneas with a lamellar interface.
Posted by A R Naderi MD,
MKH
Posted by Ali Reza Naderi at 08:58 PM
Improvements After Sheathotomy for Branch Retinal Vein Occlusion Documented by Optical Coherence Tomography and Scanning Laser Ophthalmoscope
OPHTHALMIC SURGERY, LASERS AND IMAGING Vol. 34 No. 1 January/February 2003
A 55-year-old man presented with decreased visual acuity of 20/400 and central foveal thickness of 450 µm as measured using optical coherence tomography due to a superior temporal branch retinal vein occlusion. Adventitial sheathotomy was performed with a 25-gauge sutureless transconjunctival vitrectomy system. At 1 day, 1 month, and 6 months postoperatively, visual acuity improved to 20/80, 20/40, and 20/30 OS, respectively; central foveal thickness decreased to 228, 195, and 161 µm, respectively; and the scanning laser ophthalmoscope microperimetry showed improved retinal sensitivity and fixation pattern with more stable and central fixation at both postoperative visits. This case indicates optical coherence tomography can detect an early positive effect of sheathotomy surgery on macular edema, and scanning laser ophthalmoscope can document associated improvement in fixation stability
Posted by A R Naderi MD,
MKH
Posted by Ali Reza Naderi at 08:52 PM
Final Nasolacrimal Ostium After External Dacryocystorhinostomy
Arch Ophthalmol. 2003;121:76-80
This study confirms that after successful dacryocystorhinostomy, the nasolacrimal anastomosis contracts into a relatively small ostium. Contrary to common belief, the lacrimal sac often re-forms after surgery. The final ostium frequently develops at the inferior part of the regenerated sac. Suturing the posterior lacrimal and nasal flaps in addition to the anterior flaps does not significantly affect the ultimate ostium size.
Posted by A R Naderi MD,
MKH
Posted by Ali Reza Naderi at 04:17 AM
Treatment of keratoconus by collagen cross linking
Der Opthalmologe 2003
We were able to show a significant increase in corneal stiffness of rabbit and porcine eyes after combined riboflavin/UVA-induced collagen cross-linking. In this study,we tried to treat keratoconus patients with this method to stop the progression of corneal ectasia. We treated 16 eyes of 15 patients with progressive keratoconus and mostly moderate keratectasia (48-56 dpt).After removal of the epithelium (7 mm Ø), riboflavin solution was applied on the cornea, which was irradiated with UVA (370 nm,3 mW/cm2) at a distance of 1 cm for 30 min.Post-operative follow-up controls were conducted every 3 months in the first year and then every 6 months, always including visual acuity testing, corneal topography and measurements of endothelial cell density.The follow-up time was between 1 and 3 years.
Results. Progression of keratectasia was stopped in all patients.Best corrected visual acuity and the maximal keratometry values improved slightly in about 50% of the cases. In all patients corneal transparency, the degree of keratectasia registered by corneal topography and the density of endothelial cells remained unchanged within the follow-up time.No negative side-effects were observed.
posted by A.Gholaminejad,MD
MKH
Posted by agholami at 12:32 AM
Botox usage
Eyeworld Feb 2003
Posted by M Khanlari MD
Posted by mehdi khanlari at 12:17 AM
Common Eye Diseases of Elderly People: Identifying and Treating Causes of Vision Loss
Gerontology 2003;49:1-11
Of the 38 million people who are blind, the majority, 22 million, are 60 years of age or older. The most common causes of vision loss in elderly people are age-related macular degeneration (AMD), cataract, glaucoma, and diabetic retinopathy. Of these, AMD is the leading cause of registered blindness in people over the age of 50 years in the western world. However, until recently, the treatment options for people with AMD have been severely limited. Verteporfin therapy is a new treatment that is efficacious and safe in selected patients with AMD who are at high risk of central vision loss. Physicians who are in regular contact with elderly people can help to minimize vision loss in this group of patients by being alert to the symptoms and signs of age-related eye diseases. This paper reviews each of the common eye diseases, with an emphasis on AMD because of the recent advances in treatment.
posted by A.Gholaminejad,MD
Posted by agholami at 12:10 AM
Silicone solvent developed
Eyeworld, feb 2003
Although silicone oil can be used effectively in treating retinal detachments, in patients with silicone intraocular lenses, droplets of silicone oil may stubbornly cling to the lens, causing distortion and double vision, and blurring.To remedy this problem, researchers began studying the use of semifluorinated alkanes as a silicone solvent. F6H8 (perfluorhexyloctane C14F13H17, Fluoron GmbH, Neu-Ulm, Germany) was approved in Europe in 1998 for this application. To remove silicone oil from the intraocular lens, F6H8 is applied with a syringe.There must be a mechanical force, like a jet stream.This jet stream is necessary to remove the silicone oil from the silicone lens.F6H8 then is removed completely by aspiration.F6H8 has additional ophthalmic applications as a heavier-than-water vitreous substitute to treat inferior retinal tears. Other vitreous substitutes, such as gas or silicone oil, are lighter than water.F6H8 was approved in 2000 in Europe as a temporary vitreous substitute for inferior retina detachment. F6H8 also increases the risk of cataract even when used for only three or four weeks. Although silicone oil also may induce cataracts, they do not form as quickly as they may with F6H8.Zenoni believes that F6H8 is effective in the presence of tiny silicone oil droplets, but it may be limited by the number of droplets that must be removed and the amount of time it must remain in the eye to engage the silicone oil droplets.
Posted by M Khanlari MD
Posted by mehdi khanlari at 12:01 AM
February 01, 2003
Surgeons are dyeing for visualization
in mature white cataract cases eyeworld january 2003 vol 8 number 1
by Rochelle Nataloni Contributing Editor
Ophthalmic dyes have a myriad of uses from fundus angiography and corneal marking to capsular and retinal staining. The main dyes in clinical use for cataract surgery capsule staining today are trypan blue, (Vision Blue, Dutch Ophthalmic Research Corp.) and indocyanine green (ICG, Akorn).
ICG is available in the United States under an indication for choroidal angiography, however, it is widely used off label for capsular staining. The Food and Drug Administration has not approved trypan blue for any indication. Some ophthalmologists who use this dye obtain it from compounding pharmacies.
Clinically, Trypan blue appears to have several advantages over ICG, said David F. Chang, MD, clinical professor, University of California, San Francisco. “Trypan blue, as is commercially available abroad, is formulated with the proper pH and osmolality specifically for intracameral use. Because only a small amount is needed for capsule staining, it is sold for the equivalent of $10 (U.S). ICG, in contrast, must be specially reconstituted by the operating room staff in BSS Plus and diluent in a 9-to-1 mix for intraocular use. Because it is packaged for angiography, a single vial contains 25 mg and costs $55.
“Trypan blue produces a darker and more persistent stain. This longer duration of staining allows continued visualization of the CCC throughout the phaco stage of mature cataracts,” he said. In addition to white cataracts, capsular staining is helpful in any situation where the red reflex is poor and visualization of the capsule is compromised, Chang said. This could include eyes with corneal scars, asteroid hyalosis, and brunescent nuclei. It can even be applied after the capsulorhexis has been initiated since it will preferentially stain the capsule, but not the cortex. Finally, because it enhances visualization of the capsule edge, it is useful as a learning aid for beginning surgeons, or those transitioning to new techniques such as chopping.
An identical technique is used with either dye, Chang said. Through a small paracentesis, he fills the anterior chamber with an air bubble to avoid excessive dilution of the eye. He then uses a 30-gauge cannula to place several drops of dye from a tuberculin (TB) syringe directly onto the anterior capsule surface, which is stained immediately.
Through the paracentesis, the air is then exchanged for balanced salt solution. After viscoelastic placement, Chang performs the capsulotomy in the usual manner.
“Several peer-reviewed studies have supported the safety of both capsular dyes,” Chang said. “At least U.S. cataract surgeons can still use ICG off-label for capsular staining, even though trypan blue would be a superior and less expensive alternative”.
posted by M.Taheri M.D.
Posted by at 12:51 AM