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October 31, 2003
LaserSoft
OCULAR SURGERY NEWS EUROPE/ASIA-PACIFIC EDITION November 2003
LaserSoft, a new diode-pumped all-solid-state UV laser for refractive surgery recently introduced by Katana Technologies GmbH, is an intriguing novelty in refractive surgery.A sequential frequency conversion with nonlinear crystals shifts the wavelength of the laser radiation into a range between 208 nm and 210 nm. The CW-diode pumping of the solid-state laser medium leads to very stable shot-to-shot and long-term stability of the UV output. The resonator structure and the beam delivery ensure emission of the laser radiation with a true gaussian beam, providing an excellent UV light spot distribution on the cornea, without the need for beam-forming elements in the beam path. The ablation pattern used in LaserSoft with accurate overlap of true gaussian spots ensures an extremely homogeneous corneal surface. The LaserSoft generates a flying spot of 0.2 mm in diameter, operating at a repetition rate of 1 kHz. This very small spot size fits the current requirements for effective custom ablation. There is no gas exchange and gas discharge, which may lead to instabilities in the output radiation due to the physical nature of the discharge process. The solid-state approach reduces the requirements for maintenance and the related costs, and the diode pumping system features long lifetime and efficiency.LaserSoft features an eye-tracker with a 1-ms latency, thus monitoring the ablation centration at high repetition rates. This very fast eye tracker ensures a reliable, high repetition rate centration of ablation on the X and Y axes as well as the ocular rotation. Due to the high repetition rate (1 kHz) and small spot size, the energy per pulse is lower than in standard excimer treatments. This leads to an ablation with greatly reduced stress waves. This also means no audible sound due to ablation or laser firing, and the whole procedure takes place in a silent environment, which is reassuring to the patient.The LaserSoft laser is CE mark-approved.
Posted by mehdi khanlari at 02:15 PM
The concept of ‘slow surgery’ : New philosophy for decreasing endothelial cell trauma
OCULAR SURGERY NEWS EUROPE/ASIA-PACIFIC EDITION November 2003
The derivation of the name of slow surgery is slow life and slow food. The godfather of slow surgery is Yoshihiro Tokuda, MD, of the Inoue Eye Hospital in Tokyo,” Slow surgery is a campaign with the aim of the polite operation.”Slow surgery is not merely an abstract concept. Dr. Oki said that his concerns lie primarily with high flow and vacuum technology, which he suggested are the antithesis to slow surgery, both in action and in principle.“High flow and vacuum surgery aims at the efficient operation, but slow surgery aims at the safe operation,” High flow and vacuum levels are inherently unsafe because they create anterior chamber instability, Dr. Oki noted. When phaco is performed with high flow and vacuum, the turbulence that is created sets off a “dangerous” chain of events, he added.As the turbulence increases, viscoelastic is flushed from the eye, allowing the potential for nucleus fragments to collide with corneal endothelial cells and increasing the risk of injury to the endothelium, Dr. Oki explained. He said that the mean loss in endothelial cells is about 7% using high flow and vacuum technology, but a more important statistic is the potential for cell loss of more than 20%.Dr. Oki proposes that surgeons limit vacuum pressure to 150 mm Hg and flow rate to 20 cc/min. With lower vacuum levels, the rate of corneal endothelial cell loss can be decreased to about 2%, he said.Dr. Oki also expressed concerns about the phaco chop technique, which he said is also aimed at efficiency and not safety. He said proponents of slow surgery prefer the divide-and-conquer technique, which creates smaller nucleus fragments.
Posted by mehdi khanlari at 02:05 PM
Aptos thread aids in mild to moderate brow and forehead lift
The polypropylene thread is pending approval in the United States.
OSN.11/1/2003
The aging face has sagging tissues that are currently treated with surgical lifts in different areas using different procedures. Forehead and brow ptosis are among the common problems encountered in the aging face.
Different surgical modalities have been described to correct such deformities. Major surgical operations are characterized by a difficult rehabilitation period with possible complications. Most of these techniques entail drastic surgical procedures and a long recuperation period. Sometimes there are unacceptable scars, so patients who need such corrections may be hesitant to undergo the procedures.These procedures include direct brow lift, an open flap forehead lift and an endoscopic procedure.
A less traumatic alternative is Aptos thread, developed by Dr. Marlen Sulamanidze of Moscow. The thread is not yet approved by the Food and Drug Administration for use in the United States.
This procedure can be used for other focal ptosis of soft tissues of the infraorbital, zygomatic, buccal, mental and submental areas. Aptos thread procedures are easy and quickly performed. Rehabilitation is quick, and the final outcome can be seen on the operating table at the conclusion of the procedure. It is a simple and conservative procedure that leaves no visible scars and is ideal for mild to moderate brow and forehead ptosis with excellent and long-lasting results.
Posted by afarahi at 01:57 AM
Congenital absence of the inferior rectus muscle—diagnosis and management
Journal of AAPOS,Oct,2003
Congenital absence of the inferior rectus muscle is a rare cause of apparent inferior rectus palsy especially in the absence of associated cranial facial anomalies. Failure of the normal embryologic development of the mesodermal complex around the eye can lead to agenesis of the extraocular muscles. In apparent palsies of the inferior rectus muscle and no definite cause, a high index of suspicion and orbital imaging can confirm the diagnosis of congenitally absent inferior rectus preoperatively. Strabismus surgery in conjunction with intramuscular botulinum toxin injection can offer significant improvement in function and cosmesis of these patients.
Posted by afarahi at 12:00 AM
October 30, 2003
Sudden blindness caused by anterior ischemic optic neuropathy in 5 children on continuous peritoneal dialysis1
American Journal of Kidney Diseases,Nov,2003
The authors report the occurrence of sudden blindness in 5 children (mean age, 32 months; range, 11 to 60) during continuous peritoneal dialysis regimen. All children presented with loss of light perception, visual fixation and ocular pursuit, and bilateral mydriasis unreactive to bright light. Fundoscopic examination found signs of anterior ischemic optic neuropathy with disc swelling, edema, and hemorrhages. Whereas 1 patient was dehydrated, the 4 other patients appeared well and not dehydrated. Nevertheless, blood pressure was below the normal range in all of them. Therefore, hypovolemia is highly suspected to have been the cause of ischemic optic neuropathy in all cases. Treatment consisted of steroids (4 patients), anticoagulation or antiagregation drugs (3 patients), plasma or macromolecules infusions (2 patients), vasodilatators (2 patients), and transient dialysis interruption (1 patient). One child with hepatic cirrhosis died 4 days later of acute liver insufficiency owing to ischemic hepatic necrosis. The other children had only partial improvement of vision during the following months. Because the prognosis of ischemic optic neuropathy is very poor, diagnosis and treatment of chronic hypovolemia in children on continuous peritoneal dialysis is essential to prevent such a devastating complication.
Posted by afarahi at 11:38 PM
Single-handed IOL injector receives approval
Ophthalmology Times October 1, 2003
The FDA has granted approval for the single-handed Royale Unihand Injector (model AE-9045) from American Surgical Instruments Corp. (ASICO). The IOL delivery system will accept A, B, and C Monarch cartridges for the single-piece AcrySof IOL (Alcon). The plunger-style design injects the lens smoothly into the eye. The injector is titanium and light weight, with a gold tip for better visibility through the cartridge and in the eye.
Posted by mehdi khanlari at 10:58 PM
C&C Vision Becomes Eyeonics
CRST Oct 2003
On October 1, 2003, C&C Vision (Aliso Viejo, CA) officially changed its name to Eyeonics. “The reason for the name change,” says Mary Ann Tingley, Marketing Director for C&C Vision/Eyeonics, “is that the company wants to go forward with a name that is more reflective about what we stand for—our commitment to developing evolving vision technologies that offer patients improved vision at all distances without glasses.” The company’s CrystaLens technology is currently in the final stages of FDA evaluation.
Posted by mehdi khanlari at 10:38 PM
THE VISION MEMBRANE : Design Details
CRST Oct 2003
The VISION MEMBRANE (Vision Membrane Technologies, Inc., Carlsbad, CA) is a silicone, anterior chamber phakic IOL that employs a combination of refractive optics and sophisticated diffractive optics to maintain a constant thinness in the range of 200 to 300 µm for all refractive powers. In addition, the VISION MEMBRANE is the first IOL to possess a vaulted optic (Figure 1), which provides enough clearance from the corneal endothelium to accommodate an optic of greater than 6 mm in diameter. This larger optic is critical to eliminating the halos that have been inherent in phakic IOLs with optic diameters of 4.5 mm. Moreover, the vaulted optic precludes the need for a peripheral iridectomy to prevent pupillary block and angle-closure glaucoma.The sophisticated diffractive optics of the VISION MEMBRANE provide a portion of the bifocal correction by means of an increased depth of field, rather than two disparate images created by refractive optics of two different powers. As a result, an eye implanted with the IOL should achieve distance and near visual function with high contrast at each distance.
Posted by mehdi khanlari at 10:28 PM
Normal Intersubject Threshold Variability and Normal Limits of the SITA SWAP and Full Threshold SWAP Perimetric Programs
Investigative Ophthalmology and Visual Science. 2003;44:5029-5034
PURPOSE. To compare intersubject variability and normal limits of threshold values between the new Swedish interactive test algorithm short wavelength automated perimetry (SITA SWAP) and the older Full Threshold SWAP programs (Carl Zeiss Meditec, Dublin, CA).
METHODS. Normal reduction of differential light sensitivity with age, age-corrected thresholds, intersubject variability, and normal limits of sensitivity were calculated from SITA SWAP and Full Threshold SWAP fields obtained in 53 normal subjects between 20 and 72 years of age.
RESULTS. Age influence on threshold sensitivity was the same with the two SWAP programs. On average, sensitivity decreased by 0.13 dB per year of age. Age-corrected normal threshold sensitivity was significantly higher (P < 0.0001) for SITA SWAP than for Full Threshold SWAP. The means for a subject 45.4 years of age were 28.8 dB with SITA SWAP and 24.4 dB with Full Threshold SWAP. Intersubject variance was 22% smaller with SITA SWAP than with Full Threshold SWAP. Normal limits at the P < 5% significance level were, on average, 14% narrower with SITA SWAP than with Full Threshold SWAP using Total Deviations from age-corrected normal thresholds and 11% narrower when applying Pattern Deviation, which is intended to adjust for general depression or elevation of the field.
CONCLUSIONS. SITA SWAP test results from normal eyes showed higher sensitivities than results from the older Full Threshold SWAP. This represents an increase of the dynamic range, which implies that more patients can be tested with SWAP. The smaller intersubject variability with SITA SWAP means narrower normal limits and may be associated with more sensitive probability maps.
Posted by mmiraftab at 05:48 PM
Zernike Polynomial Fitting Fails to Represent All Visually Significant Corneal Aberrations
Investigative Ophthalmology and Visual Science. 2003;44:4676-4681
Michael K. Smolek and Stephen D. Klyce
CONCLUSIONS. The wavefront error correlation to acuity was moderately strong, but the corneal elevation fit error also strongly correlated with visual acuity, indicating that Zernike polynomials do not fully characterize the surface shape features that influence vision and that exist in postsurgical or pathologic eyes. In addition, the change in wavefront error when using a larger expansion series was found to increase or diminish somewhat unpredictably. The authors conclude that Zernike polynomials fail to model all the information that influences visual acuity, which may confound clinical diagnosis and treatment.
Posted by mmiraftab at 05:39 PM
October 27, 2003
FDA approves Morcher capsular tension rings
OSN 10/27/03
The Food and Drug Administration has approved a German manufacturer’s capsular tension rings for marketing in the United States.
Morcher GmbH received U.S. regulatory approval for its Capsular Tension Ring models 14, 14A and 14C. Capsular tension rings are designed to stabilize the capsular bag in cases of posterior capsular tear or zonular dehiscence, allowing an IOL to be implanted in the bag when it might otherwise have had to be positioned elsewhere. Morcher sought approval for its rings to be used for capsular bag stabilization in patients with pseudoexfoliation syndrome or other situations of compromised zonules, according to the proceedings of an FDA panel discussion.
In 2000, the injector used to place the ring was approved by the FDA. In 2002, the FDA’s advisory Ophthalmic Devices Panel recommended that the PMA was approvable but requested “essentially a complete reanalysis of the clinical data to resolve discrepancies in the PMA and to clarify information presented at the panel meeting,” according to the FDA’s Donna Lochner, who addressed the panel at a May meeting.
German-based Morcher has appointed FCI Ophthalmics as its U.S. distributor. For more information on the Morcher devices and other capsular tension rings, click here.
Posted by mmiraftab at 10:40 PM
PRK with adjunctive mitomycin C seems to be a safe and effective option in Refractive Errors After PKP
CRST Oct 2003
Excimer laser photoablation is an alternative for visual rehabilitation in these patients, but performing LASIK in post-PKP keratoconus patients raises concern, because the surgeon creates the lamellar flap in an ectatic recipient bed. For a keratoconus patient with pre-existing corneal ectasia sufficient to have required a PKP, LASIK may increase his risk of developing corneal ectasia and recurrent keratoconus in the graft. PRK after PKP commonly causes corneal haze thereby limiting the effectiveness of the procedure. Investigators have demonstrated, however, that the use of mitomycin C (MMC) can effectively prevent haze after PRK.5 We recently investigated the safety and efficacy of topical MMC combined with PRK for treating post-PKP refractive errors in keratoconus patients.
CONCLUSIONBased on the results of our study, PRK with adjunctive MMC appears to safely treat refractive errors after PKP for keratoconus and effectively prevent postoperative corneal haze. Nevertheless, long-term follow-up and a controlled trial of PRK with adjunctive MMC after PKP compared with LASIK after PKP for keratoconus are needed.
Posted by mehdi khanlari at 10:39 PM
Treatment of Ligneous Conjunctivitis with Topical Plasmin and Topical Plasminogen
Cornea 2003; 22(8):760-762
To describe treatment of a child with recalcitrant ligneous conjunctivitis secondary to a systemic plasminogen deficiency.
A seven-year-old boy developed severe unilateral membranous conjunctivitis recalcitrant to surgical debridement and treatment with topical prednisone, topical cyclosporine, and oral prednisone. Systemic evaluation revealed a severe plasminogen deficiencyTreatment with surgical debridement and topical plasmin was ineffective and resulted in prompt recurrence of dense conjunctival membranes. Treatment with topical plasminogen resulted in dramatic improvement and complete resolution of the membranes.Conclusions: Ligneous conjunctivitis is secondary to a systemic plasminogen deficiency. Treatment with topical plasminogen resulted in prompt resolution of the membranes. Treatment with topical plasmin was ineffective.
Posted by mehdi khanlari at 10:20 PM
Pterygium Surgery with Mitomycin C: How Much Sclera Should Be Left Bare?
Cornea 2003; 22(8):721-725
To evaluate the effect of covering the sclera with conjunctiva during surgical treatment of pterygium on the rate of postoperative complications, cosmetic outcome, and risk of recurrence A comparative, prospective clinical design was used. The study population consisted of 371 consecutive patients with unilateral primary advanced pterygium. All underwent bare sclera technique for pterygium excision. At completion of surgery, topical mitomycin C 0.02% was applied for 5 minutes. In the first 189 patients (group A), the conjunctiva was sutured to the sclera 2 mm from the limbus. The next 146 patients (group B), the conjunctiva was sutured at the limbus, covering the whole scleral postexcision defect. In the last 36 patients (group C), the conjunctiva remained unsutured to the sclera. The patients were followed for complications, cosmetic outcome, and recurrence for 26 months.After 26 months, 12 patients in group A (6.35%), 10 in group B (6.85%), and 9 in group C (25%) had recurrent pterygium. There were no cases of acute drug toxicity or scleral melting. Treatable delen were noted in 2 patients in group A (1.05%), 2 (1.36%) in group B, and 9 (25%) in group C. The cosmetic appearance was much better in group A than in groups B and C.Conclusions:
Leaving the whole sclera uncovered in pterygium surgery places patients at high risk of complications and recurrence. There is no difference in complications and recurrence between covering the whole sclera with conjunctiva and leaving 2 mm bare, although the latter yields a more esthetic outcome.
Posted by mehdi khanlari at 10:17 PM
Keratometric Astigmatism after Suture Removal in Penetrating Keratoplasty: Double Running Versus Single Running Suture Techniques
Cornea,Nov 2003
Keratometry and keratometric astigmatism were measured before and after suture removal. We compared these variables in 30 grafts with the double running suture technique to the same variables in 24 grafts with the single running suture technique.The final portion of the double running suture was removed 408 ± 177 (mean ± SD) days after keratoplasty, whereas the single running suture was removed 611 ± 224 days after keratoplasty (P < 0.001). After suture removal, there was no difference between the double running and single running groups in either mean keratometry [46.5 ± 1.8 diopters (D) versus 45.6 ± 2.0 D, P = 0.09, minimum detectable difference (MDD) = 1.5D] or mean astigmatism (4.6 ± 2.7 D versus 5.2 ± 3.2D, P = 0.72, MDD=2.3).In this consecutive series of corneal transplants performed by one surgeon, the results suggest no difference in astigmatism between the two suturing techniques after all sutures have been removed.
EMKH
Posted by shebadollahi at 01:16 AM
Cyclosporine drops useful in topical steroid-resistant eyes
Ophthalmology Times,Sep 2003
Fort Lauderdale, FL-Cyclosporine A drops may be an effective treatment for Thygeson's superficial punctate keratitis (SPK) over the long term. It is especially useful in patients whose disease does not respond to treatment with steroids or those whose disease responds to steroids and who have elevated IOP levels.The authors conducted a retrospective review of consecutive cases of Thygeson's SPK .The patients who were using topical 2% cyclosporine A were studied for a mean period of 14 months (range 5 to 21 months) .All patients had been treated previously with topical steroids for more than 1 year but had very frequent recurrences of the disorder after either stopping or tapering the treatment. All patients used 2% cyclosporine A drops in olive oil once every other day for at least 1 year, and all patients had adjuvant topical steroids on tapering dose discontinued after 2 to 4 weeks. Only one patient had residual subepithelial opacities that did not affect vision after 18 months of treatment. Stinging was the most frequently occurring side effect, with 66.7% of patients reporting that this side effect lasted for 5 minutes after instilling the drops. There was no evidence of any other significant ocular side effects or systemic side effects. The results of this study indicate that topical 2% cyclosporine A is safe and effective in the long-term management of Thygeson's SPK.
EMKH
Posted by shebadollahi at 12:48 AM
October 26, 2003
Alcon MicroSmooth Irrigation SleevesCRST OPct 2003
Alcon Laboratories, Inc. (Fort Worth, TX), recently introduced MicroSmooth Irrigation Sleeves, which are designed to increase surgical control in cataract removal procedures. Alcon comments that the product features a silky smooth external surface and rounded edges, resulting in less friction in the incision; the coefficient of friction is reduced by 26.7%. Benefits of the sleeves include easier wound entry, more freedom of movement, less mechanical movement of the eye, and reduced stress on ocular tissue. MicroSmooth Irrigation Sleeves are available in both standard and high-infusion models.
Posted by mehdi khanlari at 11:25 PM
Phacoemulsification without IOL implantation in patients with high myopia Long-term results
Cataract Refract Surg 2003,JUNE
To estimate the cumulative incidence of postoperative RD, rhegmatogenous retinal lesions requiring argon laser treatments, anterior (ACO) and posterior (PCO) capsule opacification, and neodymium:YAG (Nd:YAG) laser Capsulotomy in patients with high myopia who had phacoemulsification without intraocular lens (IOL) implantation. 73 eyes of 57high myope who had PE without IOL reviewed. The mean F/Uwas 62.3 months and the mean axial length, 30.22 mm . Incidence of RD and pre and postoperative prophylactic argon laser photocoagulation for rhegmatogenous retinal lesions were assessed. ACO was evaluated subjectively and PCO was evaluated using the EPCO photographic image-analysis system. The incidence of Nd:YAG laser capsulotomy was noted. Results:
Argon laser photocoagulation was performed in 8 eyes (10.9%) preoperatively and 3 eyes (4.1%) postoperatively. One RD (1.3%) was observed 26 months after surgery; no preoperative or postoperative prophylactic argon laser photocoagulation or Nd:YAG laser capsulotomy was performed in this eye. At 1 year, 49 eyes (67.1%) had mild ACO and 24 (32.8%) had anterior capsule fibrosis. The data did not change during subsequent follow-up visits. At 6 years, the mean PCO grade was 1.109 (range 0.972 to 2.931); an Nd:YAG laser capsulotomy was performed in 12 eyes (16.4%).
Conclusions: Compared with other studies that evaluated the outcomes of highly myopic patients who had cataract surgery with posterior chamber IOL implantation, our patients, who did not have IOL implantation, had a lower incidence of postoperative rhegmatogenous retinal lesions requiring argon laser treatments and a similar incidence of postoperative RD and visually significant PCO.
Posted by alireza habibollahi at 11:09 PM
Phacoemulsification using the burst mode
J Cataract Refract Surg 2003,JUNE
To compare the amount of ultrasound (US) energy required for burst mode and pulse mode during nuclear fragment emulsification. The ultrasound time (UST) and effective US power (USP) used by 2 surgeons were retrospectively compared. Nuclear fragments were emulsified using the pulse mode in 82 cases (Group 1) and the burst mode in 118 cases (Group 2). The 2 groups were divided according to nuclear hardness: 0 to 2+ (subgroups 1a and 2a) or 3+ to 4+ (subgroups 1b and 2b). The difference in nuclear hardness between Groups 1 and 2 was not statistically significant. Results: The mean UST and USP were, respectively, 1.64 minutes at 10.53% in subgroup 1a and 0.56 minutes at 10.51% in subgroup 1b. The respective means were 2.94 minutes at 15.14% in subgroup 2a and 0.75 minutes at 10.04% in subgroup 2b. The differences between subgroups were statistically significant except between subgroups 2a and 2b.
Conclusions: The burst mode increased US efficiency, especially when used for hard cataracts.
Posted by alireza habibollahi at 10:56 PM
Efficacy and wound-temperature gradient of WhiteStar phacoemulsification through a 1.2 mm incision
J Cataract Refract Surg 2003,JUNE
New York, USA: To evaluate the efficacy and wound-temperature gradients of WhiteStar micropulse technology using bimanual phacoemulsification without an irrigation sleeve through a 1.2 mm incision.
10 patients had bimanual phacoemulsification using micropulse technology without an irrigation sleeve through a 1.2 mm clear corneal incision. A thermocouple consisting of a 30-gauge copper wire was inserted into clear cornea directly adjacent to the wound to digitally record temperature gradients at the wound. Endothelial cell counts were evaluated preoperatively and postoperatively in all patients. All 10 patients maintained corneal clarity with no sign of thermal damage to the wound. The maximum corneal wound temperatures during phacoemulsification ranged from 24°C to 34°C, well below the temperature of collagen shrinkage. Endothelial cell loss at 3 months was 7%.
Conclusions:Because of the decreased thermal effect with WhiteStar technology, an irrigation sleeve over the phacoemulsification needle is superfluous. As a result, bimanual phacoemulsification can be safely performed through a 1.2 mm incision.
EMKH
Posted by alireza habibollahi at 10:50 PM
October 24, 2003
Surgical Benefits
Restasis surgical benefits
Ophthalmology Management October 2003
Restasis is helping many of my surgical patients achieve better outcomes and higher satisfaction:
Before approving a patient for LASIK, we perform an extensive dry eye evaluation including a dry eye history, lissamine green corneal and conjunctival staining, and Schirmer testing. I prescribe Restasis for any patient with preoperative dry eye and ocular surface staining. I then allow 1 to 3 months for the dry eye to improve before I perform refractive surgery.
By preoperatively improving these patients' dry eye problem, I've been able to markedly decrease the incidence of postoperative dry eye.
My cataract patients with dry eye and visual complaints have noted a dramatic improvement in their visual acuity following Restasis therapy.
Restasis has also been invaluable for corneal transplant patients who show symptoms of dry eye. Restasis not only treats their symptoms, but helps prevent graft rejection.
Explaining the etiology of dry eye disease to patients can be confusing and time-consuming. In addition, it's important to manage patients' expectations regarding Restasis. I emphasize the following points:
I tell my patients that Restasis is the first and only FDA-approved product that will increase the body's ability to produce natural, healthy tears by treating the cause of dry eye, not just the symptoms.
I always explain that Restasis will begin helping to relieve their symptoms within a few weeks or a month.
Until relief is obtained, artificial tears (e.g., Refresh) can be used intermittently with Restasis. (I tell them to wait at least 15 minutes after using Restasis before using an artificial tear.) I point out that many patients eventually stop using supplemental tears altogether.
Mild burning is experienced by about 1 out of every 7 Restasis users; I explain to patients that this is normal and will almost always resolve on its own.
Patients can wear contact lenses when using Restasis, but they need to wait 15 minutes after instilling the drops before putting in their lenses.
Finally, I make sure patients understand how to use the drops. I tell them to use one vial per day, storing the vial upright in a mug between uses (one drop in the morning, one in the evening -- or visa versa). I tell them to discard the vial after a 24-hour period to avoid contamination and the risk of complications. I also emphasize that, like any medication for a chronic condition, Restasis needs to be used on a long-term basis to ensure that symptoms of dry eye disease don't reappear.
Posted by mmiraftab at 07:19 PM
TLCV custom procedures
Ophthalmology Management October 2003
TLCVision, a provider of laser vision correction services, said custom LASIK procedures represented about 25% of total volume in its most recent 3-month reporting period. The company said future bookings suggest that momentum for custom treatment is gradually building.
Posted by mmiraftab at 07:13 PM
Epikeratome approved
Ophthalmology Management October 2003
CIBA Vision has received FDA approval for the Centurion SES EpiEdge epikeratome. The EpiEdge, which is used in a new refractive procedure called Epi-LASIK, is a sub-epithelial separator that produces an epithelial sheet. This eliminates the need for alcohol in refractive laser procedures such as LASEK and PRK, resulting in faster healing and less pain for patients, according to CIBA Vision.
Epi-LASIK was developed by Ioannis Pallikaris, M.D., Ph.D., a Greek ophthalmologist who was also instrumental in introducing LASIK.
Posted by mmiraftab at 07:11 PM
This site offers useful information on corneal transplants
Ophthalmology Management October 2003
Though most ophthalmologists don't perform corneal transplants as a regular part of their practice, each of you will at some time examine patients who may be good candidates for a corneal transplant procedure. Fortunately, the Eye Bank Association of America (EBAA) Web site, www.restoresight.org, contains a wealth of useful information on corneal transplantation that can be of value to both patients and eyecare professionals.
Posted by mmiraftab at 06:56 PM
October 21, 2003
Late-onset diffuse lamellar keratitis
Japanese Journal Of Ophthalmology,September 2003.
Diffuse lamellar keratitis (DLK) is marked by the presence of diffuse or multifocal infiltrates confined to the laser in situ keratomileusis (LASIK) interface. These infiltrates are culture-negative, and the etiology is thought to be noninfectious. Most cases of DLK occur within the first week or 2 following surgery.
We described 2 cases of DLK that occurred 3 months after LASIK.
Treatment with topical corticosteroid was instituted, with rapid improvement in patient symptoms, visual acuity, and slit-lamp biomicroscopic findings.
DLK may occur as late as 3 months after LASIK.
ESMM
Posted by shebadollahi at 10:39 PM
Penetrating keratoplasty in children: visual and graft outcome
British Journal Ophthalmology,October 2003 .
19 penetrating keratoplasties were done in 18 eyes of 16 children, age range 2 weeks to 14 years 8 months (mean 9.24 years), with mean follow up 6.6 years. 73.7% of grafts have remained clear for up to 14 years. Postoperative visual acuity among congenital indications for graft was better than 6/60 in only 14.2% of cases, but was better than or equal to 6/12 in all cases of keratoconus.
This series shows that prolonged corneal graft survival can be achieved in children, but successful restoration of visual acuity depends upon a period of normal visual development before the onset of corneal opacification.
EMKH
Posted by shebadollahi at 10:19 PM
Terms for photic phenomena
Journal of Cataract & Refractive Surgery Volume 29, Issue 9 , September 2003 , Page 1650
I believe distinctive terms are often used interchangeably. Glare, edge glare, and dysphotopsia (of the positive and negative sort) are a few of these terms. It is not just semantics. Words have specific meanings. If used inaccurately, these terms indicate a pathophysiology that can be misleading. Allow me to remind readers of the traditional definitions of these words.
Glare means visual function with increased luminance. This is the basis for evaluating the visual dysfunction of cataract using the Brightness Acuity Test (Marco Ophthalmic, Inc.). If there is no reduction in visual acuity in the presence of increased luminance, we should not use the term glare. Unless the glare is clearly the result of light reflecting off the edge of an IOL, the term edge glare should not be used. True edge glare can be caused by flare, a streak of light reflected from an external optic edge in the pupillary aperture (as in the consultation patient) or by an arc of light caused by internal reflection from the optic edge (as described with square-edged IOLs). True edge glare is a stereotypical, reproducible phenomenon; it can be demonstrated in the exam room.
Photopsia is simply the perception of a light flash. It originally came into use to describe the flashes of light seen by patients with optic neuritis. It is a general term to describe light flashes of any etiology and, arguably, should not be restricted to cases of optic neuritis only. The prefix dys- applied to this term indicates that the flash of light is bad, impairing, causing dysfunction. That is, as with glare, there must be some disability to properly affix dys- to photopsia. All of us have had patients who reported infrequent flashes of light that caused no visual disability; these patients do not have glare or dysphotopsia.
What about the use of "positive and negative dysphotopsia?" The use of the adjective positive is redundant; it makes sense only in contradistinction to negative dysphotopsia. But this term twists the etymology of photopsia into meaninglessness. Why are we trying to describe the diminution of light, a shadow, by calling it negative light? Why not just call it a shadow. This has the virtue of having been defined as a relative darkness secondary to deflection or reflection of a portion of incoming light.
The patient described in the consultation section does indeed have glare, edge glare, and dysphotopsia; she cannot drive at night because of flare from the optic edge (which should be tested in the examination chair to see whether the symptoms can be reproduced with a flashlight). But there are additional possible causes of photic phenomena in this patient unrelated to the IOL, such as the unfocused light through her inferior iris defect and posterior vitreous detachment, which is common in patients after cataract extraction (if it has not already occurred). We are told that her capsule is clear, but the halos could also be caused by significant pigment dispersion or by tear-film debris in a patient with dry eyes.
To summarize: Every postoperative photic phenomenon is not IOL related; every light flash does not cause glare; all glare is not edge related; every photopsia is not dysphotopsia; and a negative dysphotopsia is better described as a shadow.
Posted by mmiraftab at 07:02 PM
Partial rectus muscle–augmented transpositions in abduction deficiency
Journal of AAPOS,Oct,2003
Lateral posterior fixation sutures increase the effect of full rectus extraocular muscle transpositions. Partial rectus muscle transposition may be indicated to minimize the risk of anterior ischemia when multiple rectus muscles require surgery to achieve ocular alignment.
Ten cases of unilateral split rectus muscle transposition augmented with lateral posterior fixation sutures were analyzed. Five patients had Duane's syndrome with esotropia in primary position, and five patients had sixth-nerve palsy.
In Duane's syndrome patients, the preoperative angle of deviation at distance was 15.8 ± 5.8 prism diopters (PD) (range, 10 to 25) compared with 3.2 ± 4.4 PD (range, 0 to 8) postoperatively (P = .005). In patients with sixth-nerve palsy, the preoperative angle of deviation at distance was 45.2 ± 23.9 PD (range, 16 to 80) compared with –5 ± 14.1 PD (range, –30 to 5) postoperatively (P = .004). Postoperative binocular single visual fields enlarged in seven of seven patients.
Conclusion Partial rectus muscle–augmented transposition allows surgery on multiple ipsilateral rectus muscles in (1) Duane's syndrome patients with esotropia, marked cocontraction, and/or limitation to both horizontal rotations and in (2) sixth-nerve palsy patients with ipsilateral medial rectus tightness. Augmented partial rectus muscle transpositions improve ocular alignment and may enlarge binocular single fields in patients with persistent deviations despite previous muscle surgery.
Posted by afarahi at 10:32 AM
October 20, 2003
Phacoemulsification using the burst mode
JCRS June 2003 Volume 29 June 6
To compare the amount of ultrasound (US) energy required for burst mode and pulse mode during nuclear fragment emulsification. ]The ultrasound time (UST) and effective US power (USP) used by 2 surgeons were retrospectively compared. Nuclear fragments were emulsified using the pulse mode in 82 cases (Group 1) and the burst mode in 118 cases (Group 2). The 2 groups were divided according to nuclear hardness: 0 to 2+ (subgroups 1a and 2a) or 3+ to 4+ (subgroups 1b and 2b). The difference in nuclear hardness between Groups 1 and 2 was not statistically significant. Results: The mean UST and USP were, respectively, 1.64 minutes ± 0.98 (SD) at 10.53% ± 4.46% in subgroup 1a and 0.56 ± 0.46 minutes at 10.51% ± 5.80% in subgroup 1b. The respective means were 2.94 ± 1.36 minutes at 15.14% ± 4.49% in subgroup 2a and 0.75 ± 0.52 minutes at 10.04% ± 3.12% in subgroup 2b. The differences between subgroups were statistically significant except between subgroups 2a and 2b. Conclusions:The burst mode increased US efficiency, especially when used for hard cataracts.
EMKH
Posted by alireza habibollahi at 03:15 PM
Results of phacoemulsification in eyes with preexisting glaucoma filters
JCRS 2003
A retrospective analysis of 58 eyes that had temporal phacoemulsification via a clear corneal (32 eyes) or a scleral tunnel (26 eyes) approach after filtration surgery was performed with a minimum follow-up of 12 months.Results:
The mean preoperative IOP in all eyes was 11.8 mm Hg ± 4.2 (SD), and the mean final postoperative IOP was 13.7 ± 4.6 mm Hg (P<.022). The mean preoperative BCVA was improved postoperatively .There was no statistically significant change in glaucoma medication requirements postoperatively. The differences in IOP, BCVA, and postoperative glaucoma medication requirements were not statistically significant between the clear corneal group and the scleral tunnel group or between patients who received mitomycin at the time of filtration surgery and those who did not. There were no intraoperative complications; 1 patient required additional glaucoma surgery.
Conclusion:
Clear corneal or scleral tunnel phacoemulsification in the setting of a preexisting glaucoma filter was associated with improved BCVA, a small but statistically significant increase in IOP, and stability in the number of glaucoma medicines required for IOP control over a minimum follow-up of 1
EMKH
Posted by alireza habibollahi at 03:08 PM
the differences in technique, complications, and outcomes in a large series of cataract extractions in patients with and without pseudoexfoliation (PEX) syndrome.
J Cataract Refract Surg 2003
A retrospective analysis was performed of 297 cases of cataract extraction in patients with PEX and 427 cases of in patients without PEX. Results: The overall rate of vitreous loss was 4% (7/297) in the PEX population and 0% (0/427) in the non-PEX group. There were no overall differences in the rate of postoperative complications. At 2 years, IOP had declined from a mean of 16.8 to 13.9 mm Hg in the PEX group and from 16.3 to 14.4 mm Hg in the non-PEX group. The decline was significantly greater in the PEX group. The prevalence of hypertension and diabetes was significantly greater in the non-PEX group (50% and 11%, respectively) than in the PEX group (38% and 5%, respectively).Conclusion:The increased complications during cataract extraction in PEX patients stemmed from zonular weakness rather than capsule tears. Postoperative IOP declines were greater in the PEX group even 2 years after cataract extraction, suggesting the potential for long-term improvement in outflow facility in patients with coexisting cataract and glaucoma.
EMKH
Posted by alireza habibollahi at 02:57 PM
October 19, 2003
Effects of Contact Lenses on Corneal Thickness and Corneal Curvature During Usage
Contact Lens Association of Ophthalmologists Journal ,Oct,2003
Conclusions:
Soft contact lenses and rigid gas-permeable contact lenses cause corneal thickening and corneal flattening in the first months, but they cause corneal thinning and corneal steepening with time. These alterations can be evaluated as evidence that contact lenses negatively influence corneal physiology
Posted by afarahi at 09:22 PM
Early surgical intervention as definitive treatment for ocular adnexal capillary haemangioma
Clinical & Experimental Ophthalmology,Oct, 2003
Capillary haemangioma is the most common orbital and eyelid tumour of childhood . Periorbital haemangiomas can cause amblyopia . Oral and intralesional steroids are considered to be the most accepted form of primary treatment. The authors have been performing early surgery as definitive treatment in selected lesions and their conclusion is: Early surgical intervention should be considered in a multidisciplinary team approach as a primary treatment option with selected, isolated haemangiomas, without a significant cutaneous component. Surgery is a safe, effective treatment for selected lesions, provides a definitive early treatment, and prevents astigmatism and occlusion-related amblyopia.
Posted by afarahi at 09:03 PM
Aberrant Corneal Nerve Regeneration after PRK
Cornea. 2003 Oct;22(7):684-686
One patient underwent bilateral PRK to correct a refractive error of -5.50 D in each eye. Thirteen months after the original PRK, the left eye underwent an uncomplicated PRK reoperation to correct a regression of -1.00 D. The central corneas were examined by confocal microscopy preoperatively in both eyes, at 1 and 2 years after the original PRK in the right eye, and before and 1 and 2 years after the PRK reoperation in the left eye.RESULTS Aberrant anterior stromal nerves with a coiled course and irregular branching pattern were identified 22 microm deep to the most anterior keratocyte layer at 1 year after the PRK reoperation in the left eye and remained unchanged 2 years after reoperation. No abnormal stromal nerves were identified in the left eye before the reoperation or at any time in the right eye.CONCLUSION Aberrant regeneration of corneal stromal nerves may occur after myopic PRK reoperation.
Posted by pakravanmd at 03:58 AM
October 18, 2003
A population based case-control study of cataract and inhaled corticosteroids
British Journal of Ophthalmology 2003;87:1247-1251
Background/aims: Exposure to systemic corticosteroid use is known to be associated with a risk of cataract. Whether low doses of inhaled corticosteroids are associated with an increased risk of cataract is not known. This study was undertaken to quantify the risk of cataract associated with the use of inhaled corticosteroids and assess whether there is a dose-response relation.
Methods: A population based case-control study based on the General Practice Research Database in the United Kingdom. 15 479 people with cataract and 15 479 controls were matched for age, sex, practice, and observation period.
Results: The crude odds ratio for the association between any recorded exposure to inhaled corticosteroids and cataract was 1.58 (95% CI 1.46 to 1.71), reduced to 1.10 (95% CI 1.00 to 1.20) after adjustment for systemic corticosteroid exposure and consultation rate. There was a dose-response relation, the adjusted odds ratio rising from 0.99 (95% CI 0.87 to 1.13) at daily doses up to 400 µg to 1.69 (95% CI 1.17 to 2.43) for daily doses greater than 1600 µg. For the relatively small proportion of people prescribed daily doses of 1600 µg or more, 41% of their risk of cataract could be attributed to their exposure to inhaled corticosteroidsThe association was also stronger with increasing duration of use.
Conclusion: Higher doses and longer duration of exposure to inhaled corticosteroids are associated with an increased risk of cataract. The lowest doses compatible with good control of airways disease should be used. The risk of cataract associated with high doses of inhaled corticosteroids needs to be more widely appreciated.
Posted by mmiraftab at 07:20 PM
October 17, 2003
REFRACTIVE CHANGES FOLLOWING SCLERAL BUCKLING SURGERY IN JUVENILE RETINAL DETACHMENT
Retina. 23(5):629-635, October 2003
Methods: Thirty-five eyes of 35 patients (mean age, 11.5 years; range, 7-15 years) were treated using a silicone implant scleral buckling procedure. Postoperative refractive change in the treated eyes was analyzed statistically, with the fellow eyes used as controls. The effects of age at the time of surgery, length of the silicone tire, postoperative visual acuity, and postoperative refraction were also examined.
Results: The mean refractive change in treated eyes from 1 to 4 years after the procedure was -0.6 diopter (D), whereas the mean change in fellow eyes was -1.3 D. The treated eyes became less myopic than the fellow eyes (P = 0.024), particularly in patients younger than 10 years (-0.1 D versus -1.6 D, respectively; P = 0.003) or when the scleral buckle extended beyond two quadrants (-0.4 D versus -1.3 D, respectively; P = 0.020).
Conclusions: Scleral buckling resulted in significantly less myopia, particularly in younger patients and in those receiving longer buckling tires. This finding suggests that scleral buckling in children might impede ocular growth.
Posted by mriazi at 03:50 PM
October 14, 2003
Tissue Engineering of the Cornea
Cornea. 22(7) (Supplement 1):S28-S34, October 2003
Tissue engineering of the cornea represents a paradigm shift in medical treatment to overcome the present disadvantages of corneal transplantation, primarily immune rejection and the shortage of donor corneas. Transplantation of cultivated corneal epithelial cells expanded ex vivo from corneal epithelial stem cells has been developed and has already entered the clinical realm. However, there remain many hurdles to be overcome. The author and colleagues are developing a method to transplant cultivated cell sheets that uses a temperature-responsive culture dish. This article reviews the present situation regarding tissue-engineered corneal epithelium and introduces the results of this program of research.
Posted by mmiraftab at 11:26 PM
Evaluation of the Clinical Course of Dry Eye Syndrome
Arch Ophthalmol. 2003;121:1364-1368.
In 97 patients (78 women and 19 men) with ocular discomfort, a clinical diagnosis of dry eye syndrome was made based on typical symptoms and a reduced tear film breakup time of less than 10 seconds. Subsequent evaluations revealed a diagnosis of aqueous tear deficiency in 9 patients, meibomian gland dysfunction in 32 patients, and aqueous tear deficiency combined with meibomian gland dysfunction in 30 patients, aqueous tear deficiency associated with Sjögren syndrome in 12 patients, and aqueous tear deficiency and meibomian gland dysfunction associated with Sjögren syndrome in 14 patients. Follow-up assessments were performed 12 to 94 months (mean follow-up, 40 months) after the initial diagnosis At baseline, tear film function and ocular surface test results found more pathologic abnormalities and more severe subjective symptoms in patients with aqueous tear deficiency associated with Sjögren syndrome and aqueous tear deficiency and meibomian gland dysfunction associated with Sjögren syndrome compared with the other groups who had dry eye syndrome. No differences in frequency of tear substitute application were observed. At follow-up, tear breakup time, Schirmer I test results, and corneal fluorescein staining improved compared with baseline values, whereas rose bengal staining and impression cytology of the conjunctival surface remained almost unchanged. Subjective symptoms and frequency of artificial tear application were reduced. Conclusions Within the observation period of up to 8 years, the dry eye syndrome improved or stabilized under appropriate treatment. Although no patient was completely cured, subjective reports as well as frequency of artificial tear application were reduced.
Posted by mehdi khanlari at 10:18 PM
Nonmechanical Q-Switched Erbium:YAG Laser Trephination for Penetrating Keratoplasty
Experimental Study on Human Donor Corneas
Arch Ophthalmol. 2003;121:1415-1422.
Thirty human corneoscleral donor buttons unsuitable for transplantation were placed in an artificial chamber on an automated rotation device. Corneas were trephined with a Q-switched Er:YAG laser (wavelength, 2.94 µm; pulse duration, 400 nanoseconds) along (donor and recipient) aluminum silicate (ceramic) open masks. A spot diameter of 0.65 mm, energy setting of 50 mJ/pulse, and repetition rate of 5 Hz were used. Corneal thermal damage and cut regularity were quantitatively assessed in 24 corneas processed for light microscopy and by transmission and scanning electron microscopy.The stromal thermal damage was the highest (mean [SD], 8.0 [2.7] µm) at a 150-µm cut depth and decreased downward. Cut regularity was very good and did not significantly differ between donors and recipients. Scanning electron microscopy confirmed that the cuts were highly regular; transmission electron microscopy revealed 2 distinctive subzones within the stromal thermal damage zone.Conclusions Thermal damage induced by Q-switched Er:YAG nonmechanical corneal trephination was low, and the regularity of the cuts was very good.
Posted by mehdi khanlari at 10:13 PM
Feeder vessel treatment of CNV helps stabilize visual acuity
Feeder vessel treatment is aimed at cutting off the blood supply to retrofoveal occult neovascular membranes, which neovascularization is reduced and leakage is decreased without directing the laser on the fovea.Detection of the feeder vessel is obtained by high-speed angiography with scanning laser ophthalmology (Heidelberg Retinal Analyzer). For better visualization of the feeder vessel, a more concentrated indocyanine green (ICG) solution is used, then localized laser photocoagulation would applied. In some cases retreatment is needed.
Posted by kjalali at 07:32 AM
Pediatric Enucleation
Analysis of Volume Replacement
Arch Ophthalmol. 2001;119:379-384.
To determine the percent volume replacement by an implant and prosthesis, the long-term sequelae of poor volume replacement, and specific guidelines for volume replacement in pediatric patients. A retrospective observational study of 16 pediatric patients who underwent enucleation (group 1) and 31 adult patients enucleated in childhood (group 2) was performed. The total volume replacement and the volume replacement by the implant were determined. The incidence of secondary surgical procedures for superior sulcus deformity, enophthalmos, ptosis, ectropion, and socket contraction was determined. The placement of an adequately sized implant in pediatric patients may obviate the need for secondary augmentation of socket volume in adulthood. The authors suggest an implant 2 mm less in diameter than the axial length of the eye in pediatric patients.
Posted by saliakbari at 06:42 AM
Management of Post-LASIK Corneal Ectasia With Intacs Inserts
One-Year Results
Arch Ophthalmol. 2003;121:322-326
To prospectively study the effects of the use of Intacs microthin prescription inserts (Addition Technology Inc, Fremont, Calif) for the postoperative management of corneal ectasia resulting from laser in situ keratomileusis (LASIK). In this prospective nonrandomized clinical trial, 10 eyes of 7 patients with post-LASIK corneal ectasia (2 men and 5 women) aged 33 to 46 years (mean ± SD, 40.67 ± 5.99 years) were included. The follow-up ranged from 6 to 24 months (mean ± SD, 15.0 ± 6.5 months). Two Intacs segments of thickness depending on the residual refraction of the patients were inserted in each eye. Intacs were successfully implanted in all eyes. Spherical equivalent error was statistically significantly reduced after Intacs implantation (pre-Intacs, mean ± SD: -4.81 ± 3.24 Diopters (D) (range, -13.75 to -2.50 D) to -0.96 ± 2.93 D (range, -8.75 to 2.50 D) (P<.001). Pre-Intacs uncorrected visual acuity was 20/100 or worse in all eyes (range, counting fingers to 20/100) while at the last follow-up examination, 9 (90%) of 10 eyes had uncorrected visual acuity of 20/40 or better (range, counting fingers to 20/20). Three eyes maintained the pre-Intacs best spectacle-corrected visual acuity while the rest of the eyes (7) experienced a gain of 1 to 2 lines. The mean difference between pre-Intacs and last follow-up best spectacle-corrected visual acuity was a gain of 1.00 ± 0.82 lines.
Posted by saliakbari at 06:38 AM
Management of ocular torsion and diplopia after macular translocation for age-related macular degeneration: prospective clinical study
AJO, oct, 2003
Fifty-three patients were included for both objective and subjective outcomes and were evaluated after FMT(full macular traslocation), both before and after extraocular muscle surgery. Preoperative torsion for two- (n = 6), three- (n = 8), and four-muscle (n = 39) surgery groups was 21.2 ± 4.6, 30.0 ± 6.3, and 40.5 ± 8.7 degrees, respectively. At 6 months, postoperative residual torsion was significantly reduced in each group (to 3.4 ± 3.2, 5.6 ± 5.5, and 4.5 ± 6.8 degrees, respectively, for two-, three-, and four-muscle groups). Overall, 41% (26/63) of these were free of both diplopia and tilt, whereas only 5% (3/63) had both symptoms constantly.
Conclusions : Extraocular muscle surgery is effective at relieving the variable amounts of torsion produced by FMT when graded to match preoperative torsion. The majority of patients were free of disabling tilt and diplopia after extraocular muscle surgery.
Posted by afarahi at 12:41 AM
The course of moderate amblyopia treated with atropine in children: experience of the amblyopia treatment study
AJO, oct, 2003
A beneficial effect of atropine is present throughout the age range of 3 years old to younger than 7 years old, and with an acuity range of 20/40 to 20/100. A shift in near fixation to the amblyopic eye is not essential for atropine to be effective in all cases. Sound eye acuity should be monitored when a plano spectacle lens is prescribed for the sound eye to augment the treatment effect of atropine.
Posted by afarahi at 12:34 AM
The course of moderate amblyopia treated with patching in children: experience of the amblyopia treatment study
AJO, oct, 2003
In the treatment of moderate amblyopia, a beneficial effect of patching is present throughout the age range of 3 years old to younger than 7 years old and the acuity range of 20/40 to 20/100. At 6 months, the amount of improvement appears to be similar when 6 hours of daily patching are initially prescribed vs a greater number of hours. However, when the baseline acuity is 20/80 to 20/100, a greater number of hours of prescribed patching may improve acuity faster.
Posted by afarahi at 12:31 AM
October 13, 2003
Cataract surgery and intraocular lens implantation in a retinoblastoma case treated by external-beam radiation therapy
J Cataract Refract Surg 2003
We report a case of extracapsular cataract extraction with posterior chamber intraocular lens implantation in a pediatric patient with a radiation-induced cataract that developed after combined external-beam radiation therapy and chemotherapy for retinoblastoma. A 12-year follow-up revealed effective tumor regression and sustained visual recovery.
Posted by alireza habibollahi at 10:34 PM
Lateral tarsorrhaphy for prevention of postoperative complications resulting from globe luxation
J Cataract Refract Surg 2003
We present a case of spontaneous globe luxation and wound dehiscence that developed in a patient with proptosis 1 day after phacoemulsification with posterior chamber intraocular lens implantation. The wound was repaired and a lateral tarsorrhaphy was performed with successful prevention of further luxations. Upon cataract extraction in the patient's other eye, lateral tarsorrhaphy was performed concurrently to prevent operative complications. This report underscores the importance of lateral tarsorrhaphy performed at the time of cataract surgery to avoid postoperative globe luxation with possible wound dehiscence in patients with proptosis or shallow orbits and a history of luxation.
Posted by alireza habibollahi at 10:27 PM
October 12, 2003
Bausch and Lomb Hansatome Microkeratome
Techniques in Ophthalmology 2003; 1(2):89-91
The Bausch and Lomb Hansatome corneal microkeratome is the world's most commonly used keratome for refractive surgery. It was conceived and developed by Hans Hellenkamp, the developer and manufacturer of the Automated Corneal Shaper (ACS). The ACS was originally developed for automated lamellar keratomileusis (ALK), and its combination with the excimer laser led to the advent of the LASIK (laser in-situ keratomileusis) procedure
Posted by mmiraftab at 07:42 PM
Staging of Functional Damage in Glaucoma Using Frequency Doubling Technology
Journal of Glaucoma 2003; 12(5):417-426
One hundred and four patients with either ocular hypertension or chronic glaucoma were tested with both standard automated perimetry (SAP, 30-2 Humphrey threshold test) and frequency doubling technology (N-30 threshold test). Standard automated perimetry results were classified into four groups (normal tests, early defects, moderate defects, and severe defects) using the Glaucoma Staging System. Frequency doubling technology tests were also classified in four groups using three different approaches: frequency doubling technology probability map analysis, considering the number and location of disturbed points, frequency doubling technology MD and PSD indices, graphed on a two-axis diagram (FDT Staging System), and an abnormality score, based on both the statistical significance and the spatial location of depressed points. A control group of 20 eyes from 20 normal subjects was also tested and classified in the same way. The Cohen Kappa was used to compare the level of agreement between the three frequency doubling technology methods of classification and the glaucoma staging system.
Results:
Measure of agreement was 0.679 using probability map assessment, 0.793 using the frequency doubling technology staging system, and 0.663 using the abnormality score. The specificity rate was 95% for all three methods.
Conclusions:
All the studied approaches were able to correctly stage the glaucomatous functional damage, but the frequency doubling technology staging system was the easiest and quickest method. Moreover, it is the only method that supplies information on the characteristics of the defect, without requiring any other time-consuming procedures.
Posted by mmiraftab at 07:36 PM
Tear Function and Ocular Surface Changes with Topical Mitomycin (MMC) Treatment for Primary Corneal Intraepithelial Neoplasia
Cornea 2003; 22(7):627-639
We describe seven patients with unilateral CIN treated with 0.04% topical MMC three times daily until full eradication of the lesion. The patients underwent tear and ocular surface examinations including Cochet-Bonnet corneal sensitivity measurements, tear film break-up time (BUT), Schirmer test, and Rose-Bengal staining before, at the time of resolution of the CIN, and at the final follow-up. Conjunctival impression cytology was performed before treatment and at the last visit.
Results:
The mean pretreatment corneal sensitivity was 30.3 ± 7.4 mm and improved to 55 ± 5 mm at the final visit (P < 0.05) . There were no aqueous-deficient eyes. The BUT values and Rose-Bengal staining scores also showed significant improvement at the last follow-up compared with the pretreatment values (P < 0.05). Initial impression cytology specimens showed goblet cell loss, higher grades of squamous metaplasia, areas of isolated keratinized, binucleated, and actively mitotic disfigured epithelial cells in all patients. The mean goblet cell density and squamous metaplasia grade were observed to improve significantly at the last visit (P < 0.05). MMC-induced cytologic changes were seen to persist long after cessation of treatment in some patients. All eyes remained free of recurrence and complications during the follow-up period.
Conclusion:
We found 0.04% topical MMC treatment tid until full eradication to be effective in the management of CIN. The ocular surface disease of CIN was characterized by disturbance of tear film stability, goblet cell loss, and increased squamous metaplasia in all patients. Impression cytology proved useful in attaining the diagnosis of CIN, evaluating the effect of treatment, and showing MMC-related long-term changes on the ocular surface.
Posted by mmiraftab at 07:31 PM
Water-mist product restores moisture to dry, irritated eyes
Ophthalmology Times October 1, 2003
Portland, OR-Nature's Tears EyeMist is a breakthrough product for the treatment of a variety of ocular irritations that delivers an ultra-fine mist of water to soothe and heal dry, irritated eyes The eye mist, developed by Bio-Logic Aqua Technologies, consists of tissue-culture-grade water that is delivered via a patent-pending ultra-fine mist. It restores the moisture volume of the eye's tear film without disruption, he said. "Nature's Tears EyeMist is a unique product to add to the clinician's armamentarium for patients with a wide variety of ocular irritation and complaints,"This is the first product for dry, irritated eyes that uses a water mist rather then chemical eye drops, The ultra-fine mist easily passes through the lipid layer into the aqueous layer, leaving both intact and functioning. Thus, the tear film's water content is restored to a normal, healthy state with no harsh chemicals or floodingBecause Nature's Tears EyeMist is convenient and easy to use, patients use it more frequently, and this is one of the cornerstones of its success"When the eyes are dry and the tear osmolarity is elevated, a second or two of mist will make them normal again," Nature's Tears EyeMist is so gentle, it doesn't alter the osmolarity very much. The cells don't have to adjust to it immediately, and thus you don't have the 'shock' that occurs when eye drops are administered."
Posted by mehdi khanlari at 06:47 PM
October 11, 2003
B&L's eye system wins OK
Company aims to double its share of lasik vision surgeries.With approval from the Food and Drug Administration for its custom laser eye surgery system, Bausch & Lomb Inc. is aiming at doubling its share of procedures performed in the United States and boosting revenue from the surgeries. The FDA action, announced by the company Friday, gives approval for use of B&L’s Technolas 217z Zyoptix system for a somewhat broader range of vision problems than the company’s main competitors in the field, VISX and Alcon. Patients in clinical trials of Zyoptix also have had better results after lasik surgery than those reported by competitors, B&L says. “B&L will gain market share from weaker systems,” said Jason Mills, an analyst with investment firm First Albany. “But VISX is a tough competitor. It will be difficult to take share immediately. Over time, outcomes will determine share. If outcomes are meaningfully better with Zyoptix, more will go to B&L. Time will tell.”B&L is the third company to get FDA approval for a custom system. Alcon got the OK last October and VISX in May. VISX has almost a 50 percent share of the U.S. refractive surgery market, which includes lasik. B&L has about 10 percent. B&L Chief Executive Ronald Zarrella has set a target of 18 months to double the company’s market share. Industry experts estimate about 50 million Americans are candidates for laser vision correction. B&L would get more money for each procedure that uses Zyoptix. B&L has marketed the system outside the United States. Since 2001, surgeons have used the Zyoptix system to perform about 100,000 lasik procedures in Europe, Asia, Latin America and Canada.
EMKH
Posted by at 03:01 PM
FDA Approves Bausch & Lomb Technolas 217z Zyoptix System
Bausch & Lomb has received approval from the U.S. Food and Drug Administration for its patented, advanced laser eye surgery system -- the Bausch & Lomb Technolas(R) 217z Zyoptix(TM) System for Personalized Vision Correction -- now making the world''s leading technology for custom laser eye surgery available in the United States.The U.S. clinical study was the basis for the Company''s FDA submission. It was conducted at three centers in the United States: Houston (with Dr. Slade), Rochester, N.Y. (with Dr. MacRae) and Overland Park, a suburb of Kansas City, Kan. (with Dr. Dan Durrie). Clinical trial results are based on a cohort of 340 eyes with a combination of myopia and astigmatism. Highlights include:After surgery with the Zyoptix system: * 91.5% of patients had unaided 20/20 vision or better (Uncorrected Visual Acuity); * 70.3% of patients had unaided 20/16 vision. * More than 94% of subjects maintained or improved from their best-corrected vision six months post-operatively. Six months after surgery with the Zyoptix system: * 99.0% of subjects reported that they were satisfied with the results; * 99.7% indicated improvement in quality of vision, of which more than 40% reported improvement in night vision while driving. * No patients reported dissatisfaction with their outcomes.
EMKH
Posted by at 02:46 PM
Free-floating cyst in the anterior chamber: Ultrasound biomicroscopic reports
Eur J Ophthalmol 2003; 13: 653 - 655
Case report.
A 26-year-old man presented with noise in his left eye in the prone position. Slit-lamp examination revealed a small pigmented mass lesion at the 6 o’clock position in the anterior chamber, slowly moving with changing head postures. UBM revealed an unfixed dislodged pigmented cyst with a thin wall and no internal reflectivity, changing its shape from ovoid to circular. Five years later, the anterior segment does not show any modification and the cyst has not changed in size or appearance.
CONCLUSIONS Cysts of the iris pigment epithelium arise in the posterior iris layer. They may be central, midzonal, peripheral, or dislodged. Dislodged cysts may be repositioned and fixed or free-floating in the vitreous or in the anterior chamber. Surgical removal must be considered only for a rapid enlargement or significant reduction in endothelial cell count. UBM can distinguish solid from cystic lesions, giving detailed information on internal structure, reflectivity, shape, and thickness. (Eur J Ophthalmol 2003; 13: 653-5)
Posted by mehdi khanlari at 12:38 PM
Diabetes mellitus: a risk factor affecting visual outcome in branch retinal vein occlusion Eur J Ophthalmol 2003; 13: 648 - 652
CONCLUSIONS. The VA 1 year after BRVO in patients with diabetes is worse compared to the VA in patients without diabetes. The VA stabilizes 1 year after onset in both groups. Diabetic patients tend to need more frequent follow-up in order to treat the sequelae of BRVO.
Posted by mehdi khanlari at 12:36 PM
Intraoperative biometry for intraocular lens (IOL) power calculation at silicone oil removal
Eur J Ophthalmol 2003; 13: 622 - 626
Twelve cases of cataract in eyes filled with silicone oil after retinal detachment surgery were included. Preoperatively, keratometric readings were documented. Intraoperative axial length was measured following removal of silicone oil using a sterile probe of the Nidek Echoscan US800 unit. IOL power calculation was computed using the SRK/T formula. This was followed by phacoemulsification and foldable lens implantation. Postoperative refraction allowed evaluation of the accuracy of intraoperative biometry. The predictability of three different formulas was also compared (Holladay, SRK/T, and SRK II). RESULTS. Seven men and five women with a mean age of 50.2 years were included in the study. The mean postoperative spherical equivalent using the described technique was 6.77 ± 0.43 diopters. SRK/T and Holladay formula had the best predictability for high axial length eyes, whereas the three studied formulas showed no significant differences in predictability in eyes with normal axial length. CONCLUSIONS. Intraoperative biometry proved to have good predictability for the absolute postoperative refractive error in cataract surgery for eyes at the time of silicone oil removal. This predictability was accurate independent of axial length
Posted by mehdi khanlari at 12:31 PM
October 10, 2003
Comparison of scleral and corneal tono-pen readings
Journal of AAPOS, August, 2003
Intraocular pressure (IOP) was measured prospectively in 72 eyes of 37 adult patients and in 10 eyes of 5 children. Measurements were taken on the central cornea and on the sclera. Corneal IOP ranged from 10 to 28 mm Hg (mean ± standard deviation, 17.0 ± 3.8 mm Hg). Scleral measurements ranged from 4 to 99 mm Hg (40.4 ± 23.0 mm Hg). Scleral measurements ranged from 11 mm Hg lower to 76 mm Hg higher than corneal measurements.
Conclusions Tono-Pen readings obtained from sclera are of no clinical value and should not be used to approximate corneal IOP.
Posted by afarahi at 08:22 PM
Anterior and posterior capsulorhexis in pediatric cataract surgery with or without trypan blue dye: Randomized prospective clinical study
JCRS, Sep, 2003
In a prospective randomized study, an anterior (ACCC) and posterior (PCCC) continuous curvilinear capsulorhexis were performed in pediatric patients. In Group 1 (n = 19), the ACCC and PCCC were created without use of trypan blue dye. In Group 2 (n = 23), intracameral trypan blue dye was used to stain the anterior and posterior capsules.
In Group 1, 14 eyes (73.6%) had a complete ACCC and 10 (52.6%) had a complete PCCC. In Group 2, 21 eyes (91.3%) had a complete ACCC and 19 (82.6%) had a complete PCCC.
Conclusion: In cases of pediatric cataract, staining the anterior and posterior capsules with trypan blue 0.1% allowed recognition of capsule flaps and facilitated the creation of complete ACCCs and PCCCs.
Posted by afarahi at 08:17 PM
Bleeding During Gonioscopy after Deep Sclerectomy
Journal of Glaucoma 2003; 12(5):427-429
We described two eyes of two patients with open-angle glaucoma and cataract who were operated on of an uneventful phacoemulsification and DS with SK-gel® implantation.Bleeding during gonioscopic examination occurred in both eyes 7 and 8 months after combined surgery. The blood originated from the vessels around the Descemet window, and was probably due to manipulation or rocking of the goniolens. Pressure was immediately applied to the gonioscopic lens and the hyphema was interrupted Conclusion: These cases show the presence of new vessels around the Descemet window after DS with SK-gel®. Bleeding from the Descemet window vessels can occur during gonioscopy even months after DS. We recommend conducting a careful gonioscopic examination in patients who have undergone DS to avoid this complication.
Posted by mehdi khanlari at 04:39 PM
Influence of Serum Levels of Sex Hormones on Intraocular Pressure in Menopausal Women
Journal of Glaucoma 2003; 12(5):436-440
Our data provide evidence for a relation between serum testosterone levels and IOP in menopause. Higher testosterone seems to have a tendency to increase IOP in menopausal women.
Posted by mehdi khanlari at 04:37 PM
Cataract surgery and the 5-year incidence of late-stage age-related maculopathy Ophthalmology (2003) 110: 1960-1967
Pooled findings from these two large population-based cohorts support the hypothesis that cataract surgery in older persons may be associated with an increased subsequent risk for developing late-stage ARM, particularly neovascular ARM.
Posted by mehdi khanlari at 04:19 PM
Difference map or single elevation map in the evaluation of corneal forward shift after LASIK
Ophthalmology (2003) 110: 1926-1930
Forward shift of the cornea after excimer laser refractive surgery has been assessed on a difference map generated from two elevation maps of the scanning-slit corneal topography. The current study was conducted to test whether similar evaluation is possible on a postoperative color-coded elevation map alone.The amount of forward shift of the posterior corneal surface was determined at the center of the difference map generated from preoperative and postoperative elevation maps. For surface alignment in the difference map, the 3-mm wide peripheral annular fit-zone was used. The eyes were classified into two groups depending on the amount of forward shift, using 50 µm as the threshold. Next, on the single postoperative color-coded elevation map, which is drawn relative to the individual best-fit sphere, the eye was judged to be abnormal (with significant forward shift) when more than three colors (discriminant number) were found within the central 3-mm area, and sensitivity and specificity were calculated. By varying the discriminant number from 3 to 9, receiver operator characteristic (ROC) curves were created. CONCLUSIONS: Forward shift of the cornea after excimer laser surgery should be evaluated on the difference map generated from two elevation maps, such as preoperative and postoperative maps.
Posted by mehdi khanlari at 04:16 PM
Postoperative astigmatism and rotational stability after Artisan toric phakic intraocular lens implantation
J Cataract Refract Surg 2003; 29:1761–1766
To evaluate deviations in the axis (intended versus achieved) and postoperative astigmatism after implantation of an Artisan toric phakic intraocular lens (IOL).This prospective study comprised 29 eyes with high ametropia and astigmatism. All eyes had uneventful implantation of a toric phakic IOL through a superior scleral tunnel incision at 12 o’clock. After a minimum of 6 months, the uncorrected visual acuity (UCVA), best correct visual acuity, refraction, and astigmatism were analyzed in all eyes. A multivariate analysis of postoperative astigmatism was performed. After a follow-up of at least 6 months, 95% of eyes were within ±1.00 diopter (D) of emmetropia and 85% of eyes has a UCVA of 20/30 or better. The difference between the mean intended cylinder axis and achieved cylinder axis was 3.9 degrees (median 3 degrees; range to 13 degrees). The difference between the mean intended axis and the achieved axis between miosis and mydriasis was 1.8 degrees (median 1.5 degrees; range 0 to 5 degrees). The mean postoperative astigmatism after 6 months was 0.56 D with an axis of 31 degrees. Doubled-angle scatterplot analysis showed a tendency toward more flattening in the vertical meridian.Conclusions: During the 6-month follow-up, no significant rotation was observed after implantation of Artisan toric phakic IOLs to correct high ametropia. A sutureless sclerocorneal superior approach for phakic IOL insertion resulted in moderate to low astigmatism. Induced astigmatism should be taken into consideration during preoperative planning.
Posted by mehdi khanlari at 03:57 PM
Successful implementation of a protocol for photorefractive keratectomy in children requiring anesthesia
J Cataract Refract Surg 2003; 29:1744–1747
To describe a protocol for treating children with photorefractive keratectomy (PRK) under general anesthesia and to review intraoperative and postoperative complications Nine patients between 3 years and 9 years of age were treated with PRK under general anesthesia for anisometropia with unilateral high myopia or high hyperopia and amblyopia of the affected eye. Induction of anesthesia and the surgical procedure were carried out in separate rooms. The laser beam was centered on the entrance pupil, and eye position was monitored throughout the procedure. Specific precautions were taken before and during the procedure to prevent unwanted effects of inhalational anesthetic agents on laser performance .All children did well, with no anesthesia-related or treatment-related complications. Conclusions: Our protocol for PRK under general anesthesia was effective and efficient in children who were unable to cooperate for the procedure using local anesthesia. It can be adapted for laser in situ keratomileusis and other refractive surgical procedures in children and uncooperative adults.
Posted by mehdi khanlari at 03:52 PM
Estimating residual stromal thickness before and after laser in situ keratomileusis
J Cataract Refract Surg 2003; 29:1674–1683
Before LASIK, the best means of estimating RST is to subtract the theoretical laser resection obtained from the laser computer and the expected flap thickness normally obtained with a given microkeratome system from the preoperative central corneal thickness. After LASIK, the most accurate means of calculating RST is to subtract the original flap thickness from the postoperative central corneal thickness.
Posted by mehdi khanlari at 03:42 PM
Knowing When to Validate IOL Calculation-3
Doctor.Hill.Com
Intraocular Lens Power
A second person should repeat the axial length measurements, keratometry readings and re-run the IOL power calculations for both eyes if:
1-The IOL power for emmetropia is greater than 3.00 diopters different than anticipated.
2-There is a difference in IOL power of greater than 1.00 diopter between the two eyes.
3-If the patient has had prior keratorefractive surgery and the calculated IOL power for standard phacoemulsification is less than +20.0 D or greater than +23.0 D.
Posted by mehdi khanlari at 07:58 AM
Knowing When to Validate IOL Calculation-2
Doctor.Hill.Com
Keratometry
A second person should confirm measurements prior to A-scan ultrasonography if:
1-The corneal power is less than 40.0 diopters, or greater than 47.0 diopters.
2-If there has been prior keratorefractive surgery. In this case the corneal power will need to be estimated by either the historical, or the contact lens method.
3-The average corneal power difference between the two eyes is greater than 1.00 diopter.
4-The patient cannot fixate, as seen with a mature cataract, or macular hole.
5-The amount of corneal astigmatism by keratometry, or topography, correlates poorly with the amount of astigmatism on the most recent manifest refraction.
6-The corneal diameter is less than 11.00 mm.
7-There is any problem with patient cooperation, or understanding.
Posted by mehdi khanlari at 07:51 AM
Knowing When to Validate IOL Calculation-1
Doctor.Hill.Com
Immersion A-scan Ultrasonography
A second person should re-measure both eyes if:
1-The axial length is less than 22.00 mm, or greater than 25.00 mm in either eye.
2-The axial length is greater than 26.0 mm, and there is a poor retinal spike, or wide variability in the readings. In this case, a B-scan should be scheduled to look for a (nasal or temporal) posterior staphyloma. At the same time, the axial length should be measured to the center of the macula by vector A-scan. If the center of the macula cannot be identified, the axial length should be measured 4.5 mm temporal to the void of the optic nerve head margin.
3-There is a difference in axial length between the two eyes of greater than 0.33 mm that cannot be correlated with the patient's oldest refraction.
4-Axial length measurements do not correlate with the patient's refractive error. In general, myopes should have eyes longer than 24.0 mm and hyperopes should have eyes shorter than 24.0 mm. Exceptions to this rule involve steep, or flat corneas. Be sure to use the oldest refractive data.
5-There is difficulty obtaining correctly positioned, high, steeply rising echoes, or wide variability in individual axial length readings for either eye.
6-There is any kind of problem with patient cooperation, or understanding.
Posted by mehdi khanlari at 07:42 AM
October 09, 2003
Single-handed IOL injector receives approval
Ophthalmology Times October 1, 2003
The FDA has granted approval for the single-handed Royale Unihand Injector (model AE-9045) from American Surgical Instruments Corp. (ASICO). The IOL delivery system will accept A, B, and C Monarch cartridges for the single-piece AcrySof IOL (Alcon). The plunger-style design injects the lens smoothly into the eye. The injector is titanium and light weight, with a gold tip for better visibility through the cartridge and in the eye.
Posted by mehdi khanlari at 11:05 PM
The Editors' Choices to feature year's top journal papers
Ophthalmology Times October 1, 2003
The American Academy of Ophthalmology (AAO) continues to workto provide the latest advances in ophthalmology through engaging new formats.. This session presents the editors' choices from among some 750 papers that appeared in their publications in the last year. The 12 papers chosen have made a contribution that either warrants consideration of a change in recommended clinical practice or appears to prove or disprove current thinking. This year's papers include:
1-A Randomized Trial of Patching Regimens for Treatment of Moderate Amblyopia in Children.
2-A Controlled Trial of Povidone-Iodine to Treat Infectious Conjunctivitis in Children.
3-High and Low Risk Profiles for the Development of Multiple Sclerosis Within Ten Years After Optic Neuritis. Experience of the Optic Neuritis Treatment Trial.
4-Corneal Thickness Measurements and Visual Function Abnormalities in Ocular Hypertensive Patients.
5-Rate and Amount of Visual Loss in 102 Patients With Open-angle Glaucoma Follow-up for at Least 15 Years.
6-Factors for Glaucoma Progression and the Effect of Treatment: The Early Manifest Glaucoma Trial.
7-Longitudinal Rates of Annual Eye Exams of Patients With Diabetes and Chronic Eye Diseases.
8-Cataract Surgery and the 5-year Incidence of Late-stage Age-related Maculopathy: Pooled Findings from the Beaver Dam and Blue Mountains Eye Studies.
9-A Randomized Clinical Trial of a Single Dose of Intravitreal Triamcinolone Acetonide for Neovascular Age-related Macular Degeneration: One-year Results.
10-Clinicopathologic Study After Submacular Removal of Choroidal Neovascular Membranes Treated With Verteporfin Ocular Photodynamic Therapy.
11-The Effect of Indocyanine-Green on Functional Outcome of Macular Pucker Surgery and Indocyanine Green-assisted Peeling of the Internal Limiting Membrane in Macular Hole Surgery Affects Visual Outcome: A Clinicopathologic Correlation.
12-Visual Acuity Loss and Clinical Observations in 361 Patients With Stargardt's Disease.
Posted by mehdi khanlari at 11:02 PM
LASIK monovision yields better results for myopes than hyperopes in study
OSN Oct 2003
LASIK monovision correction of patients with myopia and hyperopia resulted in significant differences in visual results, according to a retrospective study. Visual distance results were better in monovision for myopia, and myopes tended to be more satisfied with both full distance correction and monovision, noted Daniel Goldberg, MD, who conducted the study. Monovision patients were more likely to require enhancements than distance-only patients, but this difference was statistically significant only for hyperopes Patients were questioned about six potential side effects: glare, halo, difficulty in dim light, difficulty with depth perception, difficulty judging distance up and down stairs and difficulty judging parking a car.“There were significant differences between myopes and hyperopes with LASIK monovision,” Visual results for distance were better in myopes than in hyperopes and the former were more satisfied, on average, with full distance correction and monovision.”Of concern to the author, however, was the finding that people with hyperopia who chose monovision correction had more difficulty with the three night-vision-related and three depth-perception-related side effects.
Posted by mehdi khanlari at 10:49 PM
Ablation of flap and bed can be effective in high myopes
OSN Oct 2003
We have developed a novel technique for LASIK in eyes with high myopia with insufficient corneal thickness for conventional LASIK ablation. With the aid of intraoperative pachymetry, the actual stromal bed thickness was evaluated, and in those eyes deemed suitable, simultaneous LASIK — both stromal bed and undersurface of the flap — was performed to extend the range of myopia correction by means of LASIK The center of the entrance pupil was carefully marked with a Gulani LASIK marker and a Slade LASIK spatula on the corneal top, inked with a gentian violet solution . The peripheral cornea was also marked with a Gulani LASIK marker as a routine procedure .The hinged anterior corneal flap was temporarily elevated, and the thickness of the actual residual stromal bed was measured several times using a pachymeter .We calculated each amount of the laser ablation in stromal bed and undersurface of the flap out of the total attempted amount. We use the formula F = S(S+T) + F(S) , where F = full correction amount, S(S+T) = stromal portion (spherical correction + toric correction) and F(S) = flap portion (additional spherical correction). Toric ablation for astigmatism was performed only on the stromal bed, and the ablation on the undersurface of the flap was only for residual spherical ablation power. The application of this formula did not lead to a change in toric ablations axis on the stromal portion. The stromal ablation pattern (spherical with or without toric ablation) and the undersurface of the flap ablation pattern (spherical ablation) were identical to conventional LASIK. The laser-treated corneal flap was then folded back onto the cornea with a cannula. The interface was irrigated to remove debris with saline. The flap was applied with Johnston LASIK flap applicator to remove any fluid from the interface to enhance the seating of the flap to the stromal bed, and then painted into position with a wet, soft Merocel sponge. The flap was then allowed to settle for at least 3 minutes to ensure good adhesion between the flap and the stromal bed
Posted by mehdi khanlari at 10:34 PM
Simplified cataract surgery using disposable materials only
Eyeworld Oct 2003
Researchers sought to test if the use of disposable materials during cataract surgery would simplify and improve surgical organization and economic management. The researchers’ data was collected during 100 patients’ cataract surgeries. Topical anesthesia was used in all cases. Reusable materials included phaco and I/A cannula. Disposable materials were: Speculum - 3.2 knife for corneal incision; disposable needle; disposable hydrodissection cannula, lens insertion using a disposable RTU injector; lens introduction into the bag with an I/A cannula; no stitch, no forceps but 2 ml syringes. Researchers concluded that the disposable materials allow a better organization of surgery management. The preparation is shorter, all the materials are packed, sterilization is not necessary, the procedure is simplified for medical staff, and costs are low.
Posted by mehdi khanlari at 08:30 PM
Microwave warming of reliable IOL for easier handling
Eyeworld Oct 2003
It is accepted that warming the acrylic lens facilitates its flexibility, which is extremely important in microincision cataract surgery with rollable IOLs. Researchers placed the lens in a vial in the original box and placed it into a microwave oven just prior to opening the package and implantation. Warming the lens shortens the time the lens is exposed to the OR environment and decreases the risk of contamination. Conclusion: Microwave warming offers the possibility of a convenient, fast, and standardized way of warming acrylic IOLs.
Posted by mehdi khanlari at 08:27 PM
Consumption of fish may prevent, relieve dry eye
Eyeworld Oct 2003
Harvard Medical School researchers have discovered that eating more of the omega-3s in flaxseed and fish can help prevent and relieve dry-eye symptoms. The study, which was presented at the annual meeting of the Association for Research and Ophthalmology, Fort Lauderdale, Fla., involved 32,470 women that participated in the Women’s Health Study at Harvard. The study showed conclusively that in many patients dry eye is a dietary deficiency of the omega-3 oils found in flaxseed and fish. Omega-3s are essential fatty acids that eyes, lids and tear film need to function best, but the body cannot produce. “This is the first time there has been a definitive link established between the condition and diet,” said Jeffrey P. Gilbard, M.D., one of the study investigators. “Omega-3 help dry eye by decreasing eyelid inflammation called ‘blepharitis,’ and by improving the production of oil and water by the tear glands.” Gilbard cautions that people suffering from dry eye shouldn’t eat tuna often because of the high mercury levels.
Posted by mehdi khanlari at 08:04 PM
Corneal sensations after lasik
Eyeworld Oct 2003
Other factors at play
“We noticed that the thinner flaps increased corneal sensation,” There was also a correlation to the depth of the ablation, with larger ablations causing greater decrease in corneal sensation.
Donnenfeld finds that another factor that can play a role is the width of the hinge. “The thicker the hinge, the greater the conduit that allows enervation into the cornea,” Donnenfeld said.“When I have the opportunity, I prefer to make my hinge as wide as possible and preserve more enervation.” The diameter of the flap also comes into play. “It appears from some work that we’re doing now that the size of the flap also makes a difference, with smaller flaps with less of a loss of sensation than larger flaps“The surgeon should always try and make the flap in a way to minimize postoperative dry eye and for me that means as small a flap as possible with a large hinge and a nasal location for the hinge,” Donnenfeld said.
Posted by mehdi khanlari at 08:02 PM
Researchers expect jump in eye surgery demands
Eyeworld Oct 2003
A spike in demand for ophthalmologists is on the horizon because of the aging population.
UCLA researchers predict that a 15% increase in demand by the year 2010 and a 47% increase by 2020 will occur for the surgeons, according to a study in the August 2003 issue of the Annals of Surgery. Cardiothoracic surgery followed ophthalmology in terms of demand, showing a 42% increase by 2020. About 70% of cardiothoracic surgery is for patients over age 65.The great demand for ophthalmologists is due primarily to cataract surgeries, which currently comprise 55% of ophthalmic procedures.Otolaryngology is slated for the smallest increase at 14%. The patients that may need services from this field are often less than 15 years old — a population not expected to grow significantly.By the year 2020, the largest population surge will be in the 65 and older age group, which is expected to increase 53%, researchers said.There isn’t sufficient time to add new surgeons to the medical community to keep up with the demand due to the eight- to 14-year training needed for that profession, Etzioni said. However, time-management strategies, such as assistance with time-consuming paperwork may help surgeons maximize patient care time, he said.The study reported that general surgery, which included vascular, abdominal, gastrointestinal, hernia, breast and pediatric surgery, showed a 31% increase in demand by 2020. Urology surgeries are expected to increase 35% by 2020. Orthopedics shows a 28% increase by 2020. Neurosurgery demonstrated a 28% increase by 2020.
Posted by mehdi khanlari at 07:41 PM
New tonometer on its way
Eyeworld Oct 2003
The phosphene, dual tonometer will register intraocular pressure with two probes outside the eyelid. The first probe applies a known force on the eye, while the second probe applies growing force until the first probe is pushed back. The system is similar to that used in ocular palpitation, Fresco said.The tonometer has been successfully tested for overnight use, Fresco said, but its large size can make sleep difficult. The company is now miniaturizing the technology.
Its design for use outside the eyelid will make the tonometer more comfortable for patients, including children, and its measurements would not be impacted by variations in corneal thickness, Fresco said.The company hopes to receive Food and Drug Administration approval shortly after it is commercially available internationally.
Posted by mehdi khanlari at 07:31 PM
The end of reading glasses?
A new treatment for presbyopia patients may be within sight.
Eyeworld Oct 2003
An international collaborative study, referred to as the Restoring Accommodation Project and led by researchers at the Australian Vision Cooperative Research Centre, found that replacing the contents of monkey lenses with a soft polymer gel successfully maintained lens elasticity. The study found that the gel provided lenses with the same average refractive index as a healthy lens and up to 9.5 D of accommodation.The synthetic polymer material, which is injected into the lens as a liquid and cured with ultraviolet or visible light to turn it into a gel, may overcome the deterioration in the ability to focus on close objects that affects most people over 45.Initially, the new gel could allow surgeons to replace the use of rigid intraocular lenses, which are the standard after cataract removal, a researcher said. But the gel could appeal to a much bigger market — it could reverse presbyopia and allow patients to discard their reading glasses by replacing the hardened aging lens with a gel lens of the same accommodating properties as a ‘young’ lens . Researchers have evaluated more than 30 different polymer formulations created in collaboration with the Australian government research organization, CSIRO Molecular Science, Melbourne, that could transform from a liquid to a gel. The final product, identified only as a siloxane-based material, has both the same refractive index as the human crystalline lens and also the right biomechanical properties, according to Parel.
Posted by mehdi khanlari at 07:21 PM
October 07, 2003
Orbital implants in enucleation surgery
A report by the american academy of ophthalmology
Ophthalmology, Oct, 2003
Based on one randomized clinical trial, spherical alloplastic nonporous and nonpegged porous enucleation implants provide similar implant and prosthetic motility when they are implanted using similar surgical techniques. Coupling the prosthesis to a porous implant with a motility peg or post appears to improve prosthetic motility, but there are few available data in the literature that document the degree of the improvement. There is a widely variable incidence of porous implant exposure, but certain surgical techniques and the type of wrapping material seem to reduce the exposure rate. Additional research is needed to document the long-term incidence of complications related to porous enucleation implants and associated surgical techniques. This includes the use of wrapping materials and what procedural modifications, both surgical and prosthetic, are most effective in reducing these complications.
Posted by afarahi at 11:54 PM
Three Cases of ‘‘Domino’’ Keratoplasty
Japanese Journal of Ophthalmology Volume: 47, Issue: 5 September - October, 2003
Autograft keratoplasty of an affected cornea with clear corneal tissue from a contralateral blind eye has been reported.Autograft keratoplasty provides the advantage of zero risk of immune graft rejection. In previous cases, the right and left corneas were exchanged, which delayed suturing, leading to increased risk of expulsive hemorrhage and infection. Another problem was narrowing of the angle due to use of a same-size graft.
Here we describe a procedure we call ‘‘domino’’ keratoplasty in which a clear corneal button is trephined from the blind eye, into which an allograft is sutured, and autograft keratoplasty is performed on the eye with vision potential. As recommended in a previous report,we minimized the risk of secondary glaucoma by using grafts 0.5 mm larger than the corneal windows. When possible, frozen corneas were used for the allografts in the blind eyes.
Posted by mmiraftab at 05:21 PM
Acute Angle-closure Glaucoma Associated with Latanoprost
Japanese Journal of Ophthalmology Volume: 47, Issue: 5 September - October, 2003
Recently there is a report concerning randomized doublemasked studies that compares latanoprost with other â-blockers in patients with primary angle-closure glaucoma,and they concluded that latanoprost may be the therapeutic choice for the medical treatment of chronic angle-closure glaucoma. They did not report any acute angle-closure glaucoma symptoms in any case. All patients had had previous peripheral iridotomy.
Latanoprost has been shown to activate matrix metalloproteinases in human ciliary muscle cell cultures resulting in a reduced amount of extracellular matrix componentssuch as collagens I, III, IV. Structural changes in the collagen structure contribute to the increase in uveoscleral outflow. Sakai et al recently reported a case with ciliochoroidal effusion induced by topical