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July 28, 2003
Does Smoking Affect Intraocular Pressure? Findings from the Blue Mountains Eye Study
Journal of Glaucoma 2003; June 12(3):209-212
Purpose: To assess the relationship between smoking and intraocular pressure.
Conclusions: This study identified a modest cross-sectional positive association between current smoking and intraocular pressure.
Discussion: Although the IOP effect of smoking is not likely to be therapeutically significant, it seems reasonable for clinicians to advise smokers with glaucoma to consider cessation, as this would provide a small therapeutic adjunct to IOP-lowering medication.
Posted by pakravanmd at 10:41 PM
July 27, 2003
The Miraculous Stenopeic Spectacles (Multiple Pinhole Glasses)
What is Stenopeic (Pinhole) Glasses?
The lenses of the stenopeic glasses (also known as pinhole glasses) are not made of an opaque substance such as metal or plastic. There are rows of small holes scattered evenly on the lenses. The user looks through the small holes of the opaque material. These holes have the effect of reducing the width of the bundle of diverging rays (called a "pencil of light") coming from each point of the viewed object. Normally, the full opening of the pupil admits light. It is the improper bending of the outermost rays in that pencil of light which causes refractive errors such as myopia, hyperopia (farsightedness), presbyopia (diminished accommodative range with age) and astigmatism to be noticeable. Pinholes can bring about clearer vision in all these conditions. By blocking these peripheral rays, and only letting into the eye those rays which pass through the center portion of the pupil, any refractive error in the lens or cornea is much less noticeable.
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Posted by mmiraftab at 12:41 AM
July 26, 2003
Separate Effects of the Microkeratome Incision and Laser Ablation on the Eye Wave Aberration
Am J Ophthalmol 2003 August;136:327¨C337
RESULTS: The eye higher order aberrations had a small, but significant increase of approximately 30% 2 months after cutting a flap. No systematic changes were observed in nearly all Zernike coefficients from their preoperative levels at 2 months postflap cut. A significant difference between the study and control eyes was observed for one trefoil mode,
CONCLUSIONS: There was a wide variation in the response of individual Zernike modes across patients after cutting a flap. The majority of spherical aberration induced by the LASIK procedure seems to be due to the laser ablation and not the microkeratome cut. In addition,the total and higher order root mean square of wavefront errors were nearly identical for both the study and control eyes 3-months after the laser ablation,indicating that a procedure in which the incision and the ablation are separated in time to better control aberrations does not compromise the outcome of a conventional LASIK treatment.
Posted by mmiraftab at 12:35 PM
July 22, 2003
Gene therapy,adenovirus injection reduces abnormalbvessel growth.
Ophthalmology times,June 2002
Baltimore-the goal of study was to stop ocular angiogenesis,causes ARMD & diabetic retinopathy.by local delivery in gene therapy,we can achieve prolonged local release of the protein you are interesred in,but this technique can cause collateral vesseles formation in ischemic heart.gene therapy with endostatin or pigment epithelium-derived factor (PEDEF) has been shown to inhibit choroidal neovascularisation in the eyes of mice.A human trial is being organised for patients with the advanced stage of age-related macular degeneration
Posted by alireza habibollahi at 04:02 PM
Clear lens extraction,Good vision achieved with IOL in high myopia
Ophthalmology Times June 2002
Brescia,italy-clear lens extraction with implantation of a foldable, multifocal IOL
(Array Sa 40) in a small study of high myopic patients who were not good candidates for standard LASIK or phakic IOL implantation resulted in good near and far vision without significant complications,An IOL injector was used to deliver the foldable lens.
Posted by alireza habibollahi at 03:57 PM
A Mist for Dry Eyes
Review of Ophthalmology July 2003 
Bio-Logic Aqua Technologies Biomedical Research announced Nature’s Tears Eye Mist, a new therapy designed to soothe eye irritation resulting from dry eye, contact lenses, post-LASIK surgery, smoke, dust, air pollution and other irritants. Nature’s Tears Eye Mist uses tissue-culture grade water delivered through an ultra-fine mist to restore moisture to the eye’s tear film, returning it to its normal healthy state, without disrupting the delicate structure. The product is easily applied to the eyes by misting it across the face for one to two seconds. And it doesn’t disturb eye or facial makeup. For more information, call 1 (800) FOR-MIST or visit their website, naturestears.com.
Posted by mehdi khanlari at 12:01 AM
July 21, 2003
Rotating Camera
Review of Ophthalmology July 2003
Oculus Inc. introduced the Pentacam Imaging System, the first rotating Scheimpflug camera in the world. The Pentacam photographs the anterior segment through a rotation process that supplies pictures in three dimensions. In two seconds or less, the camera provides 50 3D scans with 500 images on each scan for a total of 25,000 measurements of the anterior chamber. The 3D chamber analyzer measures the chamber angle, volume and size. The pachymetry feature gauges corneal thickness that’s displayed as a color scheme over the entire area. Corneal topography of the front and back surfaces is available in sagittal (axial), tangential and elevation dimensions across the complete cornea from limbus to limbus. The lens densitometry feature allows ophthalmologists to scrutinize the crystalline lens for possible early opacification.The Pentacam is awaiting FDA approval.
Posted by mehdi khanlari at 11:44 PM
Minocycline May Benefit Blepharitis Patients
Review of Ophthalmology July 2003
Minocycline, an antibiotic in the tetracycline class, may offer a new weapon against lid disease, according to research at the University of Texas Southwestern Medical Center. Investigators there studied the effect of oral minocycline on meibomian-gland lipid composition in chronic blepharitis patients. Oral minocycline decreases diglycerides, free fatty acids and free cholesterol, harmful bacteria-causing by-products that result from the enzymatic action of lipases and esterases, which alter the composition of the natural oils that comprise the majority of meibomian-gland secretions—namely triglycerides, cholesterol esters and fatty wax esters. Minocycline also reduces inflammatory mediators called reactive oxygen species.
Posted by mehdi khanlari at 11:38 PM
FDA Approves CIBA’s Focus for Therapeutic Use
Review of Ophthalmology July 2003
The FDA has approved CIBA Vision’s Focus Night & Day lenses to be used as bandages to protect the cornea and relieve corneal pain following surgery and in the treatment of acute or chronic ocular pathologies. CIBA reports that the disposable soft lenses supply up to six times the oxygen to the eye of ordinary contact lenses and can be worn for up to 30 continuous nights, making them ideal for therapeutic use since wearers won’t have to repeatedly remove and insert them, and they’re disposable. The lenses are made from a new silicone hydrogel material and have a unique biocompatible surface that helps minimize protein and lipid-deposit buildup over time.The lenses are available in power ranges from +6 D to -10.00 D in two base curves. For more information, visit cibavision.com.
Posted by mehdi khanlari at 11:33 PM
Disposable IOL Inserter
Review of Ophthalmology July 2003
Bausch & Lomb added the SofPort System’s single-use, three-piece IOL inserter to allow surgeons to insert IOLs with one hand through a sub-3.0 mm incision for less invasive surgery. The smaller incision reduces the amount of trauma to the eye, thus improving patient recovery time. The SofPort System’s design gives ophthalmologists more control over the IOL insertion process. And its proprietary planar delivery method reduces the amount of lens unfolding to increase overall safety of the procedure, unlike other traditional delivery systems. For more product information, call 1 (800) 531-2020 or visit bausch.com.
Posted by mehdi khanlari at 11:31 PM
Conductive Keratoplasty to Correct Hyperopic Astigmatism
Journal of Refractive Surgery Vol. 19 No. 4 July/August 2003
Ioannis G. Pallikaris, MD, PhD; Tatiana L. Naoumidi, MD; Nikos I. Astyrakakis, OD
PURPOSE
To evaluate the efficacy of conductive keratoplasty in the treatment of pre-existing and surgically induced hyperopic astigmatism.
METHODS
In this prospective, noncomparative case series, four eyes of four subjects, two female and two male (age 25 to 47 yr) were treated for hyperopia (up to +5.50 D) and hyperopic astigmatism (up to +5.75 D) with the Refractec ViewPoint conductive keratoplasty system. The follow-up period was 6 months. Uncorrected and spectaclecorrected visual acuity, manifest and cycloplegic refraction, and videokeratographs were obtained before and after surgery. We treated two patients who had already had LASIK, one of them with a decentered ablation and the other with flap striae, one patient after PRK, and one patient with keratoconus.
RESULTS
No complications were observed. No eye lost lines of spectacle-corrected visual acuity. All eyes showed improvement of uncorrected visual acuity of 3 or more lines. Videokeratographs demonstrated improved centration and reduction in keratometric power readings. Each eye was analyzed separately, including a comparative analysis of the proposed nomograms and quality of vision after surgery.
CONCLUSIONS
Conductive keratoplasty may be a minimally invasive solution for patients with irregular hyperopic astigmatism, offering improved quality of vision in instances of flap striae by tightening the central cornea
Posted by mmiraftab at 11:01 PM
Laser in situ Keratomileusis for Correction of Induced Astigmatism From Cataract Surgery
Journal of Refractive Surgery Vol. 19 No. 4 July/August 2003
Hamid Norouzi, MD; Mohsen Rahmati-Kamel, MD
LASIK was performed on 20 eyes of 20 patients with refractive myopic or mixed astigmatism (3.00 to 6.00 D) at least 1 year after extracapsular cataract extraction with posterior chamber intraocular lens implantation without complication. Each eye received bitoric LASIK with the Nidek EC-5000 excimer laser and the Automated Corneal Shaper microkeratome.At 6 months after LASIK, mean refractive cylinder decreased from 4.64±0.63 D to 0.44±0.24 D (P<.001). Mean percent reduction of astigmatism was 90.4±5.0% (range 80% to 100%). Mean spherical equivalent refraction decreased from -2.19±0.88 D (range -1.00 to -3.88 D) to -0.32±0.34 D (range -1.25 to +0.38 D) (P<.001). Vector analysis showed that the mean amount of axis deviation was 0.7±1.2° (range 0° to 4.3°) and the mean percent correction of preoperative astigmatism was 92.1±5.9% (range 85.6% to 108%). Eighty-five percent of all eyes had a mean spherical equivalent refraction and mean cylinder within ±0.50 D of emmetropia. Change in spherical equivalent refraction and cylinder from 2 weeks to 6 months was .0.50 D in 90% (18 eyes) and 95% (19 eyes), respectively. Spectacle-corrected visual acuity was not reduced in any eye. Diffuse lamellar keratitis occurred in three eyes (15%) after LASIK, and were treated successfully with eyedrops.LASIK was an effective, predictable, stable, and safe procedure for correction of residual myopic or mixed astigmatism ranging from 3.00 to 6.00 D with a low spherical component after cataract surgery.
Posted by mmiraftab at 10:58 PM
July 18, 2003
U.S. Consumer Interest in Refractive Surgery
Ophthalmology Managemeny July 2003
Posted by mmiraftab at 04:42 PM
Ikeda Super Micro Capsulorrhexis Forceps from American Surgical Instruments Corp. (ASICO)
Ophthalmology Managemeny July 2003
Bi-manual micro-incision cataract surgery is an exciting new approach to cataract extraction, offering important advantages such as increased chamber stability, improved fluidics and greater flexibility. However, it also presents new challenges. One of the first challenges surgeons confront when performing this kind of surgery is capsulorrhexis construction. Incision size creates the initial difficulty: The instrument must pass through a 0.8-mm internal incision. Then the instrument must initiate the capsular tear and allow the surgeon to extend the tear in a carefully controlled curvilinear design. This requires specially designed forceps, and the Ikeda Super Micro Capsulorrhexis Forceps (AE-4385) from ASICO have the right characteristics to do the job.
Posted by mmiraftab at 04:30 PM
Panel OK's First Accommodative IOL
C&C Vision's CrystaLens Gets Unanimous Recommendation.
Ophthalmology Managemeny July 2003
In a milestone decision, the FDA Ophthalmic Devices Panel has voted unanimously to give the first "approvable" recommendation to an accommodative IOL. The panel recommended that C&C Vision's CrystaLens could be implanted in adults following cataract removal. Pending final approval by the FDA, the lens is expected to enter the U.S. marketplace by the end of this year.
Posted by mmiraftab at 04:24 PM
Glaucoma Treatment and Pregnancy
Ophthalmology Managemeny July 2003
Treating a pregnant or lactating glaucoma patient presents a unique challenge, as most glaucoma medications are considered a possible danger to a fetus or nursing baby. The FDA rating system shown below categorizes the risk to the fetus, relative to a drug's potential benefits:
Class A: Controlled studies show no risk to fetus. No glaucoma medications fall in this category.
Class B: No evidence of risk in humans. Here, the chance of fetal harm is remote but still possible. Alphagan, Alphagan P and Propine are listed in this class; they haven't been shown to cause impaired fertility or teratogenicity in animal models. (Unfortunately, human studies are lacking.)
Class C: Risk cannot be ruled out. Teratogenicity or fetal loss has been demonstrated in animals given much higher doses than humans receive. (For ethical reasons, human studies have not been conducted, and only anecdotal evidence of a medication's safety can be found in the literature.) All glaucoma medications other than those cate- gorized as Class B fall in this category. (The one exception is Humorsol, which is classified as Class X.) The potential benefits of drugs in this category may outweigh potential risks.
Note: Prostaglandin F 2alpha, a substance found in Xalatan and Travatan, has been used to terminate pregnancy (at plasma levels much higher than those resulting from topical glaucoma medication use). These medications are generally contraindicated for a pregnant patient.
Class D: Positive evidence of risk to fetus. No glaucoma medications fall in this category.
Class X: Contraindicated in pregnancy. Humorsol is the only glaucoma drug categorized as Class X.
Most drugs are secreted in breast milk at varying concentrations relative to plasma levels, but there is very little data on the safety of glaucoma medications for lactating women. Among the facts we do know:
Timolol, which has been shown to be concentrated in breast milk, can cause beta blockade in infants. (Despite this, the American Academy of Pediatrics has approved the use of Timolol and acetazolamide in lactating women.)
High doses of acetazolamide and brinzolamide given to lactating rats have been shown to cause decreased weight gain and failure to thrive in offspring. However, the level of acetazolamide in breast milk is one-third the level in plasma, and infants have been shown to have low plasma levels after nursing. Nevertheless, the risk of impaired renal or hepatic function and decreased weight gain must still be considered.
Alphagan has been shown to be excreted in rats' breast milk; however, human data is lacking. In rare cases, Alpha-gan has been shown to cause bradycardia, hypotension, hypothermia, hypotonia or apnea in neonates, so nursing infants are potentially at risk for these complications.
Posted by mmiraftab at 04:13 PM
July 17, 2003
High- and Low-Risk Profiles for the Development of Multiple Sclerosis Within 10 Years After Optic Neuritis
Experience of the Optic Neuritis Treatment Trial
Arch Ophthalmol. July, 2003;121:944-949.
To identify factors associated with a high and low risk of developing multiple sclerosis after an initial episode of optic neuritis.
Results; The 10-year risk of multiple sclerosis was 38%. Patients, who had 1 or more typical lesions on the baseline MRI of the brain had a 56% risk. higher numbers of lesions do not appreciably increase that risk. those with no lesions, had a 22% risk. Among the patients who had no lesions on MRI, male gender and optic disc swelling were associated with a lower risk of multiple sclerosis, as was the presence of the following atypical features for optic neuritis: no light perception vision; absence of pain; and ophthalmoscopic findings of severe optic disc edema, peripapillary hemorrhages, or retinal exudates.
Posted by pakravanmd at 10:14 AM
July 16, 2003
New type of cone cell identified
OSN 2003
Researchers at the University of Lyon believe they have found a new type of cone photoreceptor in the human retina containing the photopigment melanopsin, which may play a role in regulating circadian rhythms and other nonvisual but light-dependent mechanisms.The melanopsin was detected by performing anti-melanopsin immunohistochemistry on free-floating sections of retina obtained from human cadaver eyes. Previous studies have shown that melanopsin is expressed in a subpopulation of human retinal ganglion cells that are intrinsically photosensitive.Melanopsin expressing ganglion cells are considered to play a role in a broad range of nonvisual irradiance-detection processes due to their intrinsic photosensitivity and projections to structures mediating circadian rhythms, pupillary reflex and seasonal rhythms. A similar role can be hypothesized for melanopsin in the human retina.
Posted by kjalali at 06:45 AM
Ischemic optic neuropathy may be early sign of high cholesterol
OSN 2003
Idiopathic NAION typically occurs in people between the ages of 55 and 70, with most cases manifesting between the ages of 60 and 68. Cholesterol-associated ischemic optic neuropathy should be suspected in relatively young patients with optic disc edema or optic nerve pallor. Cholesterol-associated ischemic optic neuropathy is otherwise indistinguishable from idiopathic nonarteritic ischemic optic neuropathy (NAION). In a study at Wills Eye Hospital,37 patients (51 eyes) under 50 years old with a clinical diagnosis of NAION were compared with 74 age- and gender-matched NAION controls. The mean follow-up period was 36 weeks. Patients in the NAION group had statistically significant differences in their mean serum levels of total cholesterol, low-density lipoproteins and triglycerides. In this study, patients were unaware of lipid abnormalities until their visual problems developed, according to the researchers. Ischemic vascular disease may be more prevalent in this age group of patients than previously thought.
Posted by kjalali at 06:33 AM
July 15, 2003
LASIK Pearl :Avidance of Flap Complication
Review of Ophthalmology July 2003
Of course, the best way to manage complications is to never have them. You can come closer to this goal by taking certain steps.First, dampen the surgical gauze around the patient’s eye. This decreases the number of fibers that can break loose from the dressing and settle at the stromal interface. After applying the microkeratome’s suction ring, put pressure on both sides of the ring to set it in place for about two or three seconds. This makes an indentation in the conjunctiva, helps achieve better suction and avoids the eye drifting under the microkeratome. Also use a pneumotonometer to ensure that the intraocular pressure is at least 80 mmHg prior to proceeding with the cut. With Hansatome slightly decenter the ring in that direction. Since the flap is not completely circular, this will ensure ample stroma to ablate and won’t hit the hinge with the laser.Another tip with the Hansatome: Make sure the pole on which the keratome sits is tilted a little temporally. This allows the keratome to fit better, because, as you bring it in with your other hand to set it on the pole, it’s never completely vertical. You’ll find it fits in with less manipulation.
Posted by mehdi khanlari at 11:37 PM
LASIK Retreatment Tied to Older Age, High Myopia
Review of Ophthalmology July 2003
Patients with high myopia and astigmatism and over age 40 are more likely to undergo a second surgery to correct residual refractive error than those younger than 40 and with lower initial corrections. So says a retrospective study of the prevalence and risk factors for LASIK retreatments. The study appeared in the April issue of Ophthalmology.In the study, 2,485 eyes of 1,306 patients had LASIK surgery for myopia, hyperopia and astigmatism. Both high myopia and high astigmatism were independent predictors of the need for an enhancement. For instance, a 10-D myope had a retreatment incidence of 14 percent, whereas a 3-D myope had a 7-percent chance of needing enhancement within one year after the initial procedure.Patients between ages 41 and 50 had a one-year retreatment rate of 14 percent, compared to 5 to 9 percent for those ages 18 to 40. No significant differences in the initial refractive error were found in these two groups. Of the total cohort, 288 eyes of 233 people received one enhancement, and one eye in each of three participants with myopia required two additional procedures for undercorrection. The overall one-year incidence of a second surgery was 10.5 percent. The retreatment rates for myopic and hyperopic eyes were 12.1 percent and 6.2 percent respectively. No gender differences existed.Further, approximately 85 percent of enhancements occurred within the first year of LASIK, averaging 7.3 months between initial surgeries and retreatments. Forty-one percent of additional procedures took place between three and six months of the primary correction; the longest was about three years.
Posted by mehdi khanlari at 11:27 PM
July 14, 2003
Xylene Keratopathy: A Case Report and Review of the Literature
Cornea 2003; 22(1):88-90
Xylene keratopathy is a distinct clinical entity characterized by significantly decreased visual acuity, increased corneal thickness, and the presence of corneal epithelial and stromal vacuoles on a diffuse gray stromal background. The vacuoles are diffusely scattered, subtle, and clear on slit-lamp examination. Occasionally, white, round, denser areas can also be observed. Xylene keratopathy disappeared gradually over 4 weeks with topical steroid treatment and did not cause permanent sequelae.Xylene exposure should be considered as possible etiologic agent of vacuolar epithelial and stromal keratopathy. Exposure may occur directly as a splash of liquid or through its vapors.
Posted by mehdi khanlari at 11:07 PM
Effect of phacoemulsification on corneal thickness
AJO July 2003
To determine the immediate effect on corneal thickness of cataract extraction using phacoemulsification.Corneal thickness was measured immediately preoperative and postoperatively in 58 consecutive patients undergoing phacoemulsification in the absence of other ocular abnormalities. Corneal thickness was determined centrally and in the midperiphery of four quadrants. The last 17 eyes were also evaluated for the effect of pressure from a Honan balloon on corneal thickness.The cornea thinned in all five of the measured locations, with statistical significance being reached only in the four midperipheral quadrants. Pressure from the Honan balloon resulted in a negligible increase in corneal thickness preoperatively. Conclusions : Corneas were found to have thinned statistically significantly immediately after phacoemulsification; however, the degree of thinning has doubtful clinical significance and does not represent a significant dehydration of the cornea during the surgical procedure.
Posted by mehdi khanlari at 10:52 PM
Noninfectious uveitis and pregnancy
AJO July 2003
Many women with noninfectious uveitis will experience a flare-up in disease activity within the first 4 months of pregnancy. Later pregnancy appears to be a time of relative disease inactivity. Many will experience a rebound in activity within 6 months of delivery.
Posted by mehdi khanlari at 10:44 PM
Interferometry gives eye camera a new lease of life
Opto & Laser Europe May 2003
A retina camera that combines adaptive optics with optical coherence tomography is generating images of retinal cells with unprecedented resolution. Rob van den Berg discovers that it could lead to early detection of glaucoma.Ever since German physiologist Hermann von Helmholtz first observed the inside of the human eye with his ophthalmoscope, physicians have striven to obtain better images of the retina and unlock its secrets. Now a US expert in retinal imaging is pushing ophthalmoscope technology to its limits to try to achieve that goal. Donald Miller - who carried out much of his initial research at the University of Rochester, US, but now heads his own group at the University of Indiana - has developed a highly sensitive camera that can generate image slices of the retina to a lateral and depth resolution of just a few micrometres (2 and 4 µm respectively).
Posted by mmiraftab at 09:21 PM
July 13, 2003
Incidence of intraoperative corneal abrasions and correlation with age using the Hansatome and Amadeus microkeratomes during laser in situ keratomileusis
J Cataract Refract Surg 2003; 29:1174–1178
To compare the incidence of intraoperative corneal abrasions using the Hansatome® (Bausch & Lomb Surgical) and Amadeus (Advanced Medical Optics) microkeratomes and to determine whether there is a correlation between patient age and the occurrence of intraoperative corneal abrasions.The incidence of intraoperative corneal abrasions was significantly higher with the Hansatome microkeratome than with the Amadeus microkeratome (P =.014). There was a significant correlation between increasing patient age and the incidence of corneal abrasions with both microkeratomes (P<.05). Conclusions: Laser in situ keratomileusis surgeons should be aware that certain microkeratome designs pose a higher risk for intraoperative corneal abrasions and that older patients are more susceptible to intraoperative corneal epithelial injury. These patients should be informed accordingly for appropriate consent.
Posted by mehdi khanlari at 11:18 PM
Effects of losartan on diabetic maculopathy in type 2 diabetic patients
J Intern Med 2003; 254: 147-158.
Diabetic maculopathy (DMa) is a leading cause of visual loss in the western world. Preliminary studies have suggested that angiotensin converting enzyme inhibitors might be effective in preventing the progression of diabetic retinopathy, but no studies have quantitatively assessed the effect of this treatment on macular oedema in patients with DMa. We evaluated the effect of treatment with the angiotensin II receptor antagonist losartan on macular oedema and hard exudates in patients with an advanced stage of DM .Main outcome measures. (i) Degree of macular oedema as estimated by optical coherence tomography scanning of the retina; (ii) fundus photography and flourescein angiography; (iii) 24-h ambulatory blood pressure (BP); (iv) urinary albumin excretion (UAE); and (v) transcapillary escape rate of albumin (TERalb Conclusions. Type 2 diabetic patients with maculopathy do not seem to benefit from short-term treatment with losartan (50 mg once daily) as far as retinal thickness is concerned, as this dose may increase retinal thickness in the central macular area. Long-term studies are required to assess the clinical implications of these findings.
Posted by mehdi khanlari at 11:14 PM
Limbal Stem Cell Deficiency Following Phototherapeutic Keratectomy
Cornea 2003; 22(5):482-484
To describe a case of limbal stem cell (LSC) deficiency following phototherapeutic keratectomy (PTK).We analyzed the case of a 67-year-old man who developed LSC deficiency in his left eye following PTK for recurrent epithelial erosions. Predisposing factors included diabetes mellitus and rosacea.Surgical treatment consisted of debridement of the diseased corneal epithelium, followed by limbal autografting from the fellow eye. The cornea healed and remained transparent after 1 year. Histologic examination confirmed the diagnosis of LSC deficiency, showing the presence of goblet cells and inflammatory cells within the epithelium.The extensive corneal mechanical debridement and laser photoablation incurred during phototherapeutic keratectomy can cause clinical LSC deficiency in patients with predisposing external diseases.
Posted by mmiraftab at 09:43 PM
Decreased Pigment Epithelium-Derived Factor and Increased Vascular Endothelial Growth Factor Levels in Pterygia
Cornea 2003; 22(5):473-477
Pterygia exhibit significantly lower PEDF but higher VEGF levels than those in normal corneas and conjunctivae. The decreased PEDF level in pterygia may play a role in the formation and progression of pterygia
Posted by mmiraftab at 09:40 PM
Photorefractive Keratectomy for Treatment of Flap Complications in Laser In Situ Keratomileusis
Cornea 2003; 22(5):399-404
PRK was performed on 13 patients from 2 weeks to 6 months after LASIK flap complications. The technique used for the PRK varied. Epithelial removal was performed using no-touch phototherapeutic keratectomy (PTK) in six of the 13 patients and manual debridement in the other seven patients. A dilute solution of 20% ethanol was used to facilitate manual debridement in five of the seven patients. In two of these five patients, the epithelium was replaced as in laser-assisted subepithelial keratomileusis (LASEK). A solution of 0.02% mitomycin C was used after laser ablation to prevent haze formation in three patients. After an average 7 months of follow-up, uncorrected visual acuity was 20/20 in six patients, 20/25 in four patients, and 20/30 in two patients. The visual acuity in one patient was 20/80, purposely left undercorrected for monovision. Best spectacle-corrected visual acuity was 20/20 in 10 of 13 patients. Three patients were 20/25, losing one line of best spectacle-corrected visual acuity. On slit-lamp examination, at last follow-up appointment, stromal haze was graded from trace to none in all patients.
Posted by mmiraftab at 09:35 PM
Risk factors for hypotony maculopathy
Ophthalmology (2003) 110: 1185-1191
Young age, male gender, and myopia are significant risk factors for hypotony maculopathy. A history of diabetes and the presence of choroidal effusion are associated with a decreased risk for hypotony maculopathy.
Posted by pakravanmd at 04:17 AM
Conjunctival ulcers in behçet’s disease
Ophthalmology (2003) 110: 1137-1141
In addition to the oral and genital ulceration, ulcers can also be found in the conjunctiva of patients with Behçet’s disease. Although this is a rare clinical sign, when accompanied by uveitis or orogenital ulcers, it may suggest a diagnosis of Behçet’s disease.
Posted by pakravanmd at 04:06 AM
July 12, 2003
Phacoemulsification without intraocular lens implantation in patients with high myopia
Long-term results
J Cataract Refract Surg 2003; 29:1127–1131
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 mehdi khanlari at 11:05 PM
Outcomes of phacoemulsification in patients with and without pseudoexfoliation syndromeJ
Cataract Refract Surg 2003; 29:1080–1086 © 2003 ASCRS and ESCRS
The increased frequency of intraoperative 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.
Posted by mehdi khanlari at 10:56 PM
Ultrasound biomicroscopy for the assessment of zonules after ocular trauma
Ophthalmology July 2003
UBM is an effective method for identifying occult zonular damage in patients with anterior segment trauma. There is a significant learning curve in the examination technique. The ability to diagnose zonular rupture preoperatively is of significant benefit to the surgeon and might reduce the chance of intraoperative complications
Posted by mmiraftab at 10:58 AM
Detection of oncogenic human papillomavirus in sporadic retinoblastoma
Acta Ophthalmologica Scandinavica Volume 81 Issue 4 Page 396 - August 2003
Purpose: To investigate the presence of human papillomavirus (HPV) DNA in tumour tissue from patients with unilateral retinoblastoma.
Methods: Samples of paraffin-embedded tumour tissue from 43 children with unilateral retinoblastoma were collected to investigate the presence of HPV DNA using polymerase chain reaction (PCR) and dot blot hybridization.
Results: Oncogenic HPV DNA types 16 and 35 were detected in 12 (27.9%) of 43 tumour specimens. A higher frequency of differentiated tumours (63.3%) was observed among the HPV-positive tumours.
Conclusions: Future studies are necessary to demonstrate an association between HPV and sporadic retinoblastoma.
Posted by mmiraftab at 10:19 AM
Spontaneous retinal venous pulsation: aetiology and significance
Journal of Neurology Neurosurgery and Psychiatry 2003;74:7-9
In conclusion, SVPs ( spontaneous retinal venous pulsation ) are an important clinical sign caused by a fluctuating intravascular pressure gradient between the intraocular retinal veins and the retrolaminar portion of the CRV. The pulsations are observed as a subtle narrowing and expansion of one or more retinal veins on the optic disc and are present in 90% of normal persons. The examination technique requires adequate visualisation and magnification. The presence of SVPs allows the examiner to conclude that the patient does not have optic disc swelling and that the patient’s CSF pressure at that time is < 190 mm H2O.
Posted by pakravanmd at 03:29 AM
July 11, 2003
A New Number in the Glaucoma Equation : pac-hymetry
Ophthalmology review July 2003
The ability to create a corrected value for intraocular pressure affords the clinician a greater confidence in his assessment of a particular patient. If the cornea looks healthy and it measures within the normal limits of thickness (around 540 µm), you can believe that the pressure read by the tonometer is reasonably accurate.If however the patient comes in with a pressure of 25 mmHg and the cornea measures 650 µm, then you know that the patient has a thick cornea and the applanation tonometer has overestimated the pressure.This is where the fudge factor comes in .In general, we equate 1 mmHg for every 20 µm. That’s a total guess, but it’s the relationship we’ve decided to use, at least until somebody comes out with better evidence.” Dr. Fellman suggests entering the corrected IOP in the patient chart in parentheses next to where the pressure measurement is normally written. He believes that the indications for performing pachymetry fall into three categories. 1- on “a patient who has ocular hypertension with a normal nerve and a normal field, 2-a patient who has a suspicious nerve with low pressure in order to see if the pressure is really higher than that which you are reading, and3- on those pa-tients already diagnosed with glaucoma, so that you can feel confident in your treatment plan Finding a corneal thickness of more than 600 µm might cause a physician to dramatically alter the treatment plan; that is, to stop glaucoma treatment altogether . Dr. Fellman prefers to have the pachymetry done by the technician before he sees the patient. “The order of events that seems to work best is measuring CCT after the patient has had her acuity checked. Then, when she is seated in the exam lane for the doctor, that CCT number is ready.” Dr. Herndon’s leading caution is to make sure that the reading is taken in the center of the cornea, not in the periphery, where the reading will naturally be thicker.
Posted by mehdi khanlari at 05:21 PM
New Keratome and Epithelial Separator : BioVision AG's Centurion SES microkeratome
Ophthalmology Management July 2003
The device, which has 510(k) approval, has a proprietary cutting system that integrates the blade and cartridge into one component. It also uses a bar applanator, rather than a plate applanator, to flatten the cornea. The bar design applanates only the section of the cornea directly in front of the blade, resulting in a feathered cut and smoother-edged, "gutterless" flaps. It uses a blunt blade and low suction to mechanically separate a hinged epithelial flap. A dry, custom contact lens is placed over the flap; the flap sticks to the lens, making it easy to lift and flip over nasally. After laser ablation the flap, together with the contact lens, is placed back on the eye. This procedure has been named epi-LASIK.
Advantages of the new procedure include:
The flap separates below the basement membrane. (When alcohol is used, the cleavage plane falls within the basement membrane.) Dr. Pallikaris says that leaving the membrane intact provides much more stability and support for the epithelium. Electron microscopy has confirmed that the basement membrane is preserved.
Using the SES and contact lens minimizes flap manipulation.
Unlike a LASIK microkeratome, the separator doesn't cut into the stroma. As a result, accidental loss of the flap isn't the kind of major problem it can be in LASIK.
Early trials have shown that patients have high-quality vision by the first day post-op.
Posted by mehdi khanlari at 12:23 PM
Corneal Thickness in Patients Wearing Frequent-Replacement contact lens
Eye & Contact Lens: Science and Clinical Practice 2003; 29(1):23-26
Twenty-eight patients were fitted with ACUVUE (Johnson & Johnson) contact lenses. Central and peripheral corneal thickness was measured before contact lens fitting and after 2, 4, and 6 weeks of wearing.Analysis of variance shows that the period of contact lens wearing has no influence on central corneal thickness. After a small increase in the second week, central corneal thickness returns to the initial values in the fourth and sixth weeks of contact lens wearing. Peripheral corneal thickness was statistically related to the time of contact lens wearing (P <0.01). A statistically significant difference was observed between the baseline and peripheral corneal thickness measurements in the second, fourth, and sixth week of contact lens wearing (P <0.01).
Frequent-replacement contact lenses (ACUVUE) cause a small amount of corneal edema, which is higher in the periphery than in the center. Central corneal swelling disappears after 6 weeks of wearing, but in the periphery it remains stable throughout the period of observation.
Posted by sedigheh chinichian at 09:54 AM
Here’s how to protect your practice from a DLK outbreak
Eyeworld July 2003
Francis S. Mah, M.D
recommends the following safety procedures with any manufacturer’s microkeratomes:
1) Clean the inside of sterilizer tubing every day with alcohol.
2) Operate with one microkeratome and blade per eye.
3) Use approved detergents to clean the microkeratome head.
4) If you suspect your blades as a DLK cause, you can prevent an outbreak by investing in disposable microkeratome head and blade. Use them once then throw them away.
5) Adhere to excellent sterile surgical techniques by wearing gloves, a gown, a mask and use drapes around patient eyelids.
6) Apply a topical antibiotic before
Posted by mehdi khanlari at 08:34 AM
Cost of Smartplug
Eyeworld
Medennium is offering a $250 package for new customers. The package includes five pairs of plugs, one pair of forceps, and an instructional CD and literature.Smart Plug has very low extrusion rate. Another benefit to using Medennium’s plugs is that there is no need to have a stock of various size plugs.
Posted by mehdi khanlari at 08:10 AM
Restasis : Educating patients
Eyeworld July 2003
Because Restasis is the first medication of its kind, some patient education is usually needed. Patients should be reminded that this is a prescription medication . Restasis is not to be used as an artificial tear, which is on a PRN [as needed] basis . This is a prescription medication to be used twice daily.” With Restasis, patients can still use artificial tears with the exception of Refresh Endura (Allergan), which is the equivalent of the vehicle for the drug. Patients need to understand that Restasis can take months to work. “They have to understand that they are getting benefit of the drug even though it is not like an antibiotic where the bacteria go away and everything is fine with 48 hours. With Restasis, you get relief based upon resolution of the disease and not just based upon palliation of the ocular surface, which is a new paradigm.
Posted by mehdi khanlari at 07:55 AM
July 10, 2003
Delayed Suprachoroidal Hemorrhage Following Viscocanalostomy
OPHTHALMIC SURGERY, LASERS AND IMAGING Vol. 34 No. 3 May/June 2003
Delayed suprachoroidal hemorrhage is a rare complication of conventional glaucoma surgery. Viscocanalostomy is one of the new surgical techniques used in glaucoma surgery that may theoretically protect against suprachoroidal effusion and hemorrhage due to the nonpenetrating nature of the procedure. Delayed suprachoroidal hemorrhage developed in a 92-year-old white woman following viscocanalostomy. This case demonstrates that the risk of suprachoroidal hemorrhage may not be completely eliminated after a nonpenetrating glaucoma procedure such as viscocanalostomy.[Ophthalmic Surg Lasers Imaging 2003;34:209-211.]
Posted by mehdi khanlari at 11:36 PM
The flap’s important role in LASIK-induced dry eye
Eyeworld July 2003
When a flap is cut for LASIK, the nerves of the cornea are severed, and the eye becomes anesthetic. Because there is reduced sensation, tear production and blink rate decrease, causing dry eye.In fact, this problem is greater than simple dry eye .This is really a neurotrophic keratitis rather than a truly dry eye. Part of neurotrophic keratitis is a dry eye, but besides being dry, the cells themselves are not as healthy as they would otherwise be and they don’t heal as well Fortunately, two-thirds of patients recover corneal sensation within three months postop, and 95% recover within six months postop. For the remaining 5%, dry eye can be a permanent problem.while nasal-hinged flaps may reduce the likelihood of dry eyes, they can cause other problems. “Many believe that flap displacement and flap folds are more common with nasal hinges than with superior hinges. So it is possible that using a nasal-hinged flap may reduce the likelihood of dry eye, but it may increase the likelihood of flap folds and flap displacement. Larger flaps, particularly those made in hyperopic LASIK, tend to cause more dry eye than smaller flaps.“For hyperopic LASIK, you have to make a 9.5- or 10-mm flap, so you are cutting farther out and you are cutting more nerves. Lindstrom said that hyperopic women are particularly at risk for experiencing post-LASIK dry eye symptoms.
Posted by mehdi khanlari at 11:15 PM
Rhegmatogenous Retinal Detachment With Schwartz’s Syndrome Following Nd:YAG Laser Peripheral Iridectomy in the Management of Pigmentary Glaucoma
OPHTHALMIC SURGERY, LASERS AND IMAGING Vol. 34 No. 3 May/June 2003
A case of rhegmatogenous retinal detachment complicated by Schwartz’s syndrome following Nd:YAG laser peripheral iridectomy in the management of pigmentary glaucoma is described. A 36- year-old man underwent Nd:YAG laser peripheral iridectomy for pigmentary glaucoma. Three days later, he had a rhegmatogenous retinal detachment. The break remained open following scleral buckling with persistent subretinal fluid, “iridocyclitis,” and elevated intraocular pressure. Two months later, the patient underwent revision of the scleral buckle. Following closure of the retinal break, the retina flattened, and within 2 weeks the “iridocyclitis” resolved and the intraocular pressure decreased to approximately 20 mm Hg. Rhegmatogenous retinal detachment may occur following laser peripheral iridectomy, and suggests the necessity for a prospective clinical trial to evaluate the role of laser peripheral iridectomy in the management of pigmentary glaucoma. [Ophthalmic Surg Lasers Imaging 2003;34: 206-208.]
Posted by mehdi khanlari at 11:00 PM
Dementia with Lewy bodies :A ‘new’ type of dementia with visual symptoms
Optometry Today 2002
Patients with Alzheimer’s disease may develop a range of visual problems during the course of the disease. Those include defects in primary vision, eye movement, pupillary function, and in complex visual functions involving the ability to judge distance or to make out the shape of an object. Dementia with Lewy bodies (also known as Lewy body dementia or diffuse Lewy body disease)now recognised as the second most common type of dementia after Alzheimer’s disease and may account up to a quarter of all cases in elderly people.This disorder is characterised by a progressive, disabling mental impairment and includes fluctuating attention and alertness, visual hallucinations and the symptoms of Parkinson’s disease as typical features. Dementia with Lewy bodies is of particular interest because disorder is common and associated with a range of visual problems that, although they may overlap with those of Alzheimer’s disease, may be distinctive enough to help in clinical diagnosis.
Posted by mmiraftab at 08:57 PM
Wavefront-guided contact lens design :Principles, techniques and limitations
Optometry Today January 2003
The concept of wavefront-guided contact lens design is presented from three vantage points – ray optics, wavefront aberrations, and optical path-length errors. The most intuitive of these three is the last; an optically perfect contact lens makes all of the paths from a distant object to the retina equal in optical length, regardless of where the path penetrates the plane of the pupil. The prescription for such a lens is an aberration map which specifies how optical path differences vary across the pupil. Practical barriers to the successful correction of ocular aberrations with contact lenses include residual sphero-cylindrical errors, chromatic aberration, alignment instability, and variability of measured aberration maps.
Posted by mmiraftab at 08:43 PM
July 08, 2003
Central serous chorioretinopathy associated with administration of sympathomimetic agents
AJO July 2003
To report central serous chorioretinopathy associated with excessive use of compounds with sympathomimetic activity.Four patients presented with clinical and fluorescein angiographic evidence of central serous chorioretinopathy. All patients expressed a concomitant psychogenic stress and high-dose ingestion of pseudoephedrine, oxymetazoline, or 3,4-methylenedioxymethamphetamine, all of which possess sympathomimetic properties.In all cases, resolution of central serous chorioretinopathy coincided with cessation of the medication.Patients afflicted with central serous chorioretinopathy should be notified about its possible association with sympathomimetic medications.
Posted by mmiraftab at 10:34 PM
Changing concepts in the management of choroidal melanoma
AJO July 2003
Large choroidal tumors continue to be managed primarily by enucleation. The large tumor trial of the Collaborative Ocular Melanoma Study (COMS) demonstrated neither a positive nor negative effect on 5- and 8-year mortality rates among more than 1,000 patients whose eyes containing large choroidal melanomas were randomized to treatment between enucleation alone or enucleation preceded by external radiation. The medium-size tumor trial of the COMS randomized more than 1,300 patients between iodine-125 brachytherapy and enucleation. Mortality rates following brachytherapy did not differ from mortality rates following enucleation for up to 12 years after treatment. Iodine-125 has become the most commonly used isotope for brachytherapy in North America. Ten-year follow-up of eyes treated with helium ion and 20 years of experience with proton beam confirm the relative safety and efficacy of these modalities for treatment of choroidal melanoma. Although there is a trend toward earlier treatment of small melanomas, controversy exists regarding the indications for treatment as well as the choice of specific therapy. Recurrences of melanoma after eye-sparing treatment appear to be associated with an increased rate of metastatic disease. Effective adjunctive therapy to prevent or treat melanoma metastasis is lacking.Choroidal melanoma is a lethal tumor. Although evidence suggests that patients with untreated choroidal melanomas have a poorer prognosis than patients who receive treatment, our current treatments are unable to prevent tumor-related deaths for many patients. The use of preoperative external radiation as an adjunct to enucleation for large choroidal melanomas is unsupported by data from the COMS trial. The use of radiation with either brachytherapy or charged particles for the management of medium-size choroidal melanomas is well supported on the basis of long-term follow-up studies. There is a trend toward treatment of smaller choroidal melanomas. Treatment of melanomas should be directed toward minimizing the potential for recurrences as recurrent melanomas are associated with an increased rate of metastatic disease. Gains in our ability to manage choroidal melanoma will likely be modest at best until effective systemic therapies can be identified
Posted by mmiraftab at 10:31 PM
Glaucoma clinical trials and what they mean for our patients
AJO July 2003
Glaucoma clinical trials and observational studies strongly support the need to reduce intraocular pressures (IOP) substantially and to maintain those pressures in patients with advanced glaucoma. Whether this aggressive therapy occurs by medications or by filtering surgery does not seem as important as that the treatment is effective and sustained. However, there is not the same strength of evidence for aggressive treatment or even any treatment for most patients with ocular hypertension and for some cases of early glaucoma. Because about half of the patients with open-angle glaucoma will have IOPs less than 21 mm Hg, these patients need to be detected through careful optic disk and visual field assessment. Once patients are detected and treated appropriately, blindness from open-angle glaucoma is unlikely.The goal of managing ocular hypertension and glaucoma is not to preserve every ganglion cell, but rather to preserve a patient's visual ability to conduct activities of daily living. Risk factors for damage need to be assessed for individual patients and each patient managed as an individual and not as the ''average'' patient depicted in the results of clinical trials. In the future, neuroprotective therapy other than IOP reduction will provide another means to control glaucoma damage
Posted by mmiraftab at 10:28 PM
July 07, 2003
A randomized trial of rigid gas permeable contact lenses to reduce progression of children's myopia
AJO July 2003
Rigid gas permeable lenses did not slow the rate of myopia progression, even among children who used them regularly and consistently. It is unlikely that this intervention holds promise as a method by which to slow the rate of progression of myopia in children.
Posted by mmiraftab at 10:47 PM
Plasma homocysteine is elevated in patients with exfoliation syndrome
AJO July 2003
To compare plasma homocysteine concentrations among patients with exfoliation syndrome, exfoliative glaucoma, normal-tension glaucoma, and normal control subjects without vascular or inflammatory ocular disease or glaucoma.Although exfoliative glaucoma and normal-tension glaucoma patients were not signficantly different with respect to hyperhomocysteinemia, logistic regression modeling of exfoliative glaucoma vs normal-tension glaucoma patients showed that an increased homocysteine concentration was a significant risk factor for exfoliation syndrome in the presence of glaucoma (odds ratio per 1.0 mol/l increase in HOMOCYSTEINE = 1.2, 95% CI = 1.0–1.4). These relationships were not affected by adjustment for potential confounding due to sex, history of hypertension, or other factors.Elevated plasma homocysteine, a risk factor for cardiovascular disease, is more common in exfoliation syndrome and exfoliative glaucoma patients than healthy controls. Patients with exfoliation syndrome may benefit from measurement of homocysteine levels
Posted by mmiraftab at 10:45 PM
July 06, 2003
Tonometer tracks IOP at home :Vibration tonometry
Eyeworld July 2003
Unique technology may soon offer ophthalmologists an additional way to keep tabs on intraocular pressure in patients suspected to have glaucoma.The Eric system(Eric Technologies, Calgary, Alberta, Canada, )the home care device resembles a small pair of binoculars. Applied very lightly to closed eyelids, the system produces vibrations in the eye at amplitudes of approximately 1 mm and then measures the vibrations to determine IOP readings in both eyes simultaneously.These measurements are likely to be more accurate than are possible by measuring the changes occurring in the corneal curvature or the force or time required to indent or flatten it,. The reason for this is that the system does not change the volume of the eye and thus does not substantially affect the pressure.Because it doesn’t change the volume measurements can be repeated constantly without interfering with IOP later.Furthermore, readings with the Eric system probably will not be influenced by variations in corneal thickness, scleral rigidity, blood reflux, and other factors that can affect Goldmann tonometer readings, “Vibration tonometry is less invasive than conventional tonometry, which means a reduced risk of infection, abrasion, or other potential damage to the patient’s eye,”The system is also very simple to use, lowering training and operational costs.” The company expects to begin clinical trials in the fall and hopes to receive approval from the Food and Drug Administration early next year.
Posted by mehdi khanlari at 11:01 PM
July 04, 2003
Cataract Challenge: Piggyback implantation with an Array multifocal lens in a high myope for unilateral cataract.
Cataract & Refractive Surgery Today June 2003
CASE PRESENTATION
A 34-year-old white male contact lens wearer presented for cataract evaluation. His past ocular history was significant for a blunt injury during a hockey game to his right eye 5 years earlier. The patient’s BCVA was 20/30 OD, glaring down to 20/100, and 20/25 OS, with no change on glare testing. The examination revealed significant posterior capsular opacification of the right lens and a clear left lens.and no phacodonesis. The patient’s manifest refractions were -17.25 + 1.00 X 100 OD and -11.25 + 1.25 X 135 OS. His keratometry measurements were 41.00/42.00 D OD and 41.00/42.00 D OS. Contact A-scan biometry measured axial lengths of 31.37 mm OD and 28.99 mm OS. I found the patient’s anterior chamber depths to be 3.68 mm OD and 3.18 mm OS. Using an IOLMaster (Carl Zeiss Meditec Inc., Dublin, CA), I found the patient’s axial lengths to be 31.95 mm OD and 29.90 mm OS, and his keratometry readings were 41.36/ 42.78 @ 95 OD and 40.81/41.93 @ 120 OS.
The patient requested cataract surgery for his right eye.
HOW WOULD YOU PROCEED?
1. Would you defer cataract surgery until the patient’s left eye developed a cataract?
2. Plan cataract surgery with a highly myopic outcome so as to balance the degree of myopia?
3. Choose to follow cataract extraction by implanting an IOL that will render the patient’s right eye emmetropic?
4. Perform cataract surgery and implant a multifocal lens?
Posted by mehdi khanlari at 11:58 PM
Elevated flare may predict later graft rejection
OSN ,TOP STORY for July 4, 2003
Elevated aqueous flare after penetrating keratoplasty may be associated with later graft rejection, a long-term observational study suggests. The preoperative diagnosis and a history of implant surgery may influence aqueous flare counts in the early postoperative period, according to the study authors.
David Hui-Kang Ma, MD, PhD, and others at Taiwan’s Chang Gung University reviewed the records of 86 eyes of 86 patients who had undergone penetrating keratoplasty (PK) with a follow-up of up to 76 months. PK alone was performed on seven eyes with keratoconus, 19 with corneal scar, 16 with pseudophakic bullous keratopathy and 14 who needed regraft. PK was combined with cataract extraction and IOL implantation in 17 eyes with corneal scar and with IOL exchange in 13 eyes with bullous keratopathy.
Aqueous flare was measured with a laser flare-cell meter at 1 week and 1, 3, 6, 12 and 24 months postoperatively. Follow-up ranged from 7 to 76 months, with an average of 25 months.
Endothelial rejection occurred in 11 cases. Of those, seven cases failed. An additional 10 grafts failed from other causes. At the last follow-up, 69 grafts remained clear, according to the study authors.
There was a significant difference in aqueous flare values among eyes undergoing PK only for keratoconus, corneal scar, pseudophakic bullous keratopathy and regraft from 1 week to 3 months postop. Within the corneal scar group, aqueous flare value was significantly higher from 1 week to 3 months when combined with cataract surgery. In the pseudophakic bullous keratopathy group, the value was significantly higher from 1 week to 1 month and 6 months when combined with anterior chamber-IOL exchange.
The study is published in Cornea.
Posted by mtmdop at 08:02 PM
July 02, 2003
AcrySof Natural gains U.S. approval
O.S.N ,July 2, 2003
An IOL that filters ultraviolet and blue light has been approved for marketing in the United States, according to Alcon. The company’s AcrySof Natural is a single piece IOL “designed to approximate the light filtration properties of a healthy human lens,” the company stated in a news release.
In a clinical trial, 297 patients were randomized to bilateral implantation with either the AcrySof Natural IOL or an AcrySof lens with UV absorption only. Visual acuity outcomes were not statistically significantly different between the two types of lenses, and both types exceeded the standard Food and Drug Administration grid, according to the company. Color perception also was not statistically significantly different between the two IOLs.
“A growing body of evidence shows high frequency blue light may cause retinal damage. Knowing the AcrySof Natural IOL filters out this potentially dangerous light without negative visual consequences.
The AcrySof Natural IOL received approval for European marketing in September 2002.
Posted by afarahi at 04:47 PM
July 01, 2003
Acute retinal necrosis following epidural steroid injections
AJO July 2003
Two patients developed acute retinal necrosis syndrome following epidural corticosteroid injections for back pain. Referral was delayed in one patient. One patient developed bilateral secondary rhegmatogenous retinal detachment, and both developed secondary macular pucker.Acute retinal necrosis can follow epidural corticosteroid injections. Patients should be warned about this possibility and advised to report should photopsias, photosensitivity, blurred vision, or new floaters develop after treatment. Orthopedists should be aware of the complication and promptly refer patients with symptoms for dilated fundus examination by an ophthalmologist.Acute retinal necrosis syndrome (ARN) is a devastating viral retinitis usually caused by centrifugal spread of reactivated herpes zoster or herpes simplex virus from a dormant reservoir in the central nervous system. In this report, epidural corticosteroid injections for low back pain were followed by ARN suggesting that they were related to the viral reactivation.This study is a small case series based on review of clinical records and case photographs. Data were accumulated in conformity with all Federal and State laws.
To my knowledge, these are the first reported cases of the acute retinal necrosis syndrome developing after epidural injections of corticosteroids. Schwartz and coworkers 2 reported a case of acute retinal necrosis accompanying herpes zoster ophthalmicus occurring 7 days after initiation of oral prednisone for rheumatoid arthritis. Matsuo and coworkers 3 reported ARN in a patient on prednisolone for nephrotic syndrome who developed chicken pox. Latent herpes zoster virus is considered to be actively contained by an intact immune system. Short-lived synthesis of new virions is thought to occur intermittently as evidenced by intermittent rises in specific IgM antibody levels in asymptomatic infected patients. 4,5 4,5 Should an epidural corticosteroid injection coincide with such an episode, containment of the virus could be breached with subsequent clinical infection, such as acute retinal necrosis.
Corticosteroid injections are used in many cases for treatment of back pain. Previously reported ophthalmic complications include precipitation and exacerbation of central serous retinopathy and acute bilateral visual loss due to intraretinal hemorrhages
Posted by mmiraftab at 10:00 PM
A new, Non-contact wide field viewing system for vitreous surgery
AJO July 2003
Gholam A. Peyman 
To report a new, noncontact wide field viewing system for vitreoretinal surgery.
Device description: A noncontact wide field viewing system consisting of adjustable hinged arm and a combined condensing lens and reinverting prism has been developed. The arm clamps onto the operating table or wrist rest and holds the lens system in the air above the eye.For vitreoretinal surgery, a new, relatively inexpensive noncontact wide field viewing system consisting of an adjustable hinged arm and a combined condensing lens and reinverting prism has been developed. The combination condensing lens and reinverting prism is used without a microscope–mounted inverter. The optical component may be sterilized with ethylene oxide, peracetic acid, or glutaraldehyde. Other components may be steam autoclaved.The new, noncontact wide field viewing system has been used satisfactorily in more than 200 vitrectomies at seven medical centers. It provides an excellent view of the vitreous and retina.A new, noncontact wide field viewing system for vitreoretinal surgery has been developed with satisfactory image quality and a field of view comparable to contemporary noncontact panoramic viewing systems
Posted by mmiraftab at 09:44 PM
Pupil dilation with intracameral 1% lidocaine during glaucoma filtering surgery
AJO July 2003
The mean male pupil diameter was significantly greater than female dilation at every time point. The mean blue iris diameter was greater than brown at 1 and 3 minutes, but there was no difference at 5 minutes or more. There was no racial difference in the pupil dilation response to intracameral lidocaine.Nonpreserved intracameral 1% lidocaine produces immediate pupil dilation in previously undilated phakic patients during trabeculectomy surgery.Lidocaine is an antiarrhythmic drug as well as an effective local anesthetic. It acts by blocking sodium channels, thereby inhibiting the membrane potential. We have observed intracameral lidocaine to cause immediate pupil dilation.We have successfully used a combination of topical and intracameral nonpreserved lidocaine as a local anesthetic for a variety of glaucoma surgeries. We noticed that intracameral lidocaine usually causes rapid and extensive pupil dilation.To our knowledge, there is only one study reporting pupil dilation following lidocaine administration. In that study, intracameral anterior chamber lidocaine injection in cats caused immediate pupil dilation. There was no comment on the mechanism of action. In addition, cases in which intravitreal lidocaine injection in humans caused pupil dilation have been reported
Posted by mmiraftab at 09:34 PM
Refractive changes in pregnancy
Graefe's Archive for Clinical and Experimental Ophthalmology, 2003
Two hundred forty pregnant women were asked whether they had any alteration in vision. Those who agreed to take part in the study (83) and who complained of vision changes (12) were matched with the next patient seen in the practice who was asymptomatic.
All women who complained of visual changes were found to have experienced a myopic shift from pre-pregnancy levels. (0.87±0.3 diopters in the right eye (P<0.0001) and 0.98±0.3 diopters in the left eye (P<0.0001). Post partum, all subjects returned to near pre-pregnancy levels of myopia.
Conclusions This report links worsening of myopia to pregnancy. The causes of this myopic shift are not readily evident and merit further investigation.
Posted by afarahi at 01:24 AM