Bilateral disc edema and unilateral macular hole in a patient with retinitis pigmentosa.

PURPOSE: A unique case of retinitis pigmentosa (RP) associated with bilateral disc edema and unilateral macular hole is presented. METHODS: A 49-year-old woman, a known RP patient, was found to have bilateral disc edema and a macular hole in the left eye during routine clinical examination. Fluorescein angiography revealed hyperfluorescent leakage of the optic nerve head significantly OD and minimally OS. There was staining in the macular regions which was consistent with retinal pigment epithelium atrophy OD and cystoid macular edema (CME) OS. Cerebrospinal fluid pressure and examination by lumbar puncture was normal. Disc edema spontaneously decreased bilaterally during follow-up. DISCUSSION: Bilateral disc edema was thought to be secondary to inflammation caused by rapid degeneration of photoreceptors and retinal pigment epithelium and macular hole was secondary to CME. CONCLUSIONS: Inflammatory response in the course of retinitis pigmentosa may result in disc edema and cystoid macular edema, which may further progresses to macular hole.

A short duration transient ischemia induces apoptosis in retinal layers: an experimental study in rabbits.

PURPOSE: To investigate retinal cell apoptosis in an experimental transient, short duration ocular ischemia model. METHODS: An experimental ischemia model, which simulates creating temporary high intraocular pressure to control intraocular bleeding during pars plana vitrectomy, was set up. Rabbits were randomly divided into three groups. Group 1 was the control group. In Group 2, intraocular pressure was increased to 97 mmHg for 5 minutes. In Group 3, intraocular pressure was increased to 97 mmHg for 10 minutes. After 24 hours, terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick-end labeling assay was used to detect retinal apoptosis in rabbit eyes. Only nuclear staining in retinal cells was counted. RESULTS: Groups with 5 minutes and 10 minutes of ischemia showed significantly higher amount of ganglion cell layer apoptosis when compared with the control group (p<0.05). Light microscopy and standard hematoxylin-eosin did not show any significant damage in the retina cells. CONCLUSIONS: Apoptotic cell death in the retinal cell layers occurs in temporary ischemia-reperfusion as early as 5 and 10 minutes duration.

Assessment of retinal nerve fiber layer thickness with NFA-GDx following successful scleral buckling surgery.

PURPOSE: To assess the effect of retinal detachment (RD) on retinal nerve fiber layer (RNFL) thickness by using a scanning laser polarimeter (NFA-GDx) after successful scleral buckling surgery for the treatment of rhegmatogenous RD. METHODS: Consecutive patients who had successful scleral buckling surgery in one eye were assessed for RNFL thickness by using NFA-GDx prospectively. Fellow healthy eyes of the patients formed the control group. Eyes with RD surgery were compared with the control group with respect to three variables (superior average, inferior average, and average thickness) of NFA-GDx by using two-sampled t-test. Additionally, a possible effect of duration of RD on RNFL thickness was assessed with a correlation test. RESULTS: The study group consisted of 16 patients with a mean age of 49.8 years. The mean duration of RD was 28 days. Although the retardation values in operated eyes were less than that of the control eyes, the difference was not statistically significant (p > 0.05). However, these three values were seen to increase with increased duration of detachment and this correlation was statistically significant (R > 0.5, p < 0.03). CONCLUSIONS: RD seemed to cause minimal or no change in RNFL thickness as determined by GDx variables. The positive correlation between RNFL thickness and duration of RD, however, may be because of the proliferated Muller cells in eyes with RD, which may be responsible for some of the retardation measurements, which may be even more prominent in longstanding RD cases. This needs to be supported by further studies in larger patient groups with longer duration of RD and with histopathologic studies.

Effect of mechanical vs dilute ethanol epithelial removal on keratocyte apoptosis and polymorphonuclear leukocyte migration.

PURPOSE: To investigate keratocyte apoptosis and polymorphonuclear (PMN) cell infiltration to the corneal stroma after mechanical epithelial scraping and chemical de-epithelialization with 18% ethanol solution. METHODS: Twelve New Zealand Albino rabbits (24 eyes) were randomly divided into three groups. Group A was the control group with no epithelial removal. Group B underwent a 7.5-mm mechanical epithelial removal with a blunt spatula. Group C underwent 7.5-mm chemical de-epithelialization with 18% ethanol-balanced salt solution. Corneas were stained with terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick-end labeling (TUNEL) assay after 24 h. Only nuclear staining in keratocytes was counted. Polymorphonuclear (PMN) leukocyte densities were also assessed by light microscopy. RESULTS: Mechanical de-epithelialization (group B) and chemical de-epithelialization with 18% ethanol (group C) showed no difference in keratocyte apoptosis compared with the control group. There was also no difference between groups B and C. Group B showed no difference in PMN leukocyte counts compared with the control group. But the number of PMN leukocytes observed in group C was significantly higher than those encountered in the corneas of the control group (P < 0.05) and group B (P < 0.05). CONCLUSIONS: Dilute alcohol induces more PMN cell infiltration when compared with mechanical de-epithelialization although there is no difference in the apoptosis rates.

A case of choroidal osteoma with subsequent laser induced decalcification.

A rare benign tumor, choroidal osteoma with accompanying choroidal neovascularization treated with laser photocoagulation is reported. Limited decalcification was noted at the borders of laser photocoagulation.

Topical vitamin E and hydrocortisone acetate treatment after photorefractive keratectomy.

PURPOSE: To investigate the effects of topical vitamin E and hydrocortisone acetate treatments on corneal healing response after -10.0 D photorefractive keratectomy (PRK) in rabbits. METHODS: Thirty-three New Zealand white rabbits were divided into four groups and -10 D PRK was performed under in vivo conditions. Following PRK, group 1 (n = 9) received no topical treatment and served as control. Group 2 (n = 8) received 0.1% hydrocortisone acetate ointment twice a day, group 3 (n = 8) received 1% vitamin E ointment and group 4 (n = 8) received both 0.1% hydrocortisone acetate and 1% vitamin E twice a day for a month. At the end of the third month, corneal haze was graded and the corneal hydroxyproline levels were measured, as a crude indicator of new collagen synthesis. Finally corneal samples were examined by transmission electron microscopy. RESULTS: Non-homogeneously distributed strong haze was identified in group 1 which was greater than in the other groups; haze was least in groups 2 and 4. Corneal hydroxyproline levels were found to be significantly lower in groups 2, 3 and 4 compared with the control (Student's t-test, p < 0.05). Histopathologically, the most aggressive wound healing response was detected in group 1. The corneal wound healing response of group 2 was less than that of group 1 and equal to or more than that of group 4. CONCLUSIONS: Deep corneal photoablation induces an aggressive healing response, and topical hydrocortisone acetate reduces this corneal wound healing effectively. The inhibitory effect of topical vitamin E on corneal wound healing seems to be less than that of hydrocortisone acetate, but combined treatment with these two drugs may have an additive effect in controlling corneal wound healing after PRK.

Scanning laser polarimetry in normal subjects and patients with myopia.

AIMS: To examine the changes in the retinal nerve fibre layer (NFL) thickness with age and myopia in normal population. METHODS: Retinal nerve fibre layer thickness was measured with a scanning laser polarimeter (NFA-I) in 180 normal subjects of varying age (range 7-83 years) and in 110 eyes of 85 patients with myopia of varying degrees (range -1.00 to -15.00D). They were all voluntary Anatolian people. Superior to nasal (S/N), inferior to nasal (I/N), and the superior to inferior (S/I) ratios were used for the assessment of retinal NFL thickness. RESULTS: The mean superior NFL ratio was 2.96 and the mean inferior NFL ratio was 2.93 in normal subjects. There was a gradual decrease in NFL ratio with increasing age (simple regression analysis, p<0.05). The mean S/I ratio was 1.01 with a large variation. In patients with myopia, the mean superior NFL ratio was 2.60 and the mean inferior NFL ratio was 2.72. Superior and inferior NFL retardations, and S/I ratio in myopic patients were significantly (15.5%, 10.8%, and 4.9% respectively) lower than that of age matched normals (t test, p<0.05). There was also a gradual decrease in NFL thickness with increasing degree of myopia (simple regression analysis, p<0.05). CONCLUSIONS: Nomograms we obtained for retinal NFL thickness may serve as reference points for the assessment of normal Anatolian people and myopic patients in future studies. NFL thicknesses gradually decreased with increasing age. Patients with myopia had significantly lower NFL thicknesses than normal subjects and, although weakened by wide age range of myopic group, there is a linear relation between severity of myopia and NFL thickness in myopic patients.

Photorefractive keratectomy for visual rehabilitation of anisometropia induced by retinal detachment surgery.

PURPOSE: To evaluate the efficacy of unilateral photorefractive keratectomy to correct anisometropia induced by retinal detachment surgery. METHODS: Photorefractive keratectomy was performed in 10 eyes of 10 patients with anisometropia induced by previous retinal detachment surgery. The Aesculap Meditec MEL 60 excimer laser was used. RESULTS: Preoperative mean spherical equivalent refraction was -5.20 D. Mean postoperative spherical equivalent refraction was -0.25 D after a mean follow-up of 12.9 months. Mean preoperative spherical equivalent refraction difference between two eyes of 4.87 D was decreased to a mean 0.60 D postoperatively (t-test, P < .0001). All patients were free of anisometropic symptoms after laser surgery. CONCLUSION: Unilateral photorefractive keratectomy seems to be an effective method to correct anisometropia induced by conventional retinal detachment surgery, especially for patients with spectacle and contact lens intolerance.

Corneal iron ring after hyperopic photorefractive keratectomy.

PURPOSE: To report the incidence and course of corneal iron deposition after hyperopic photorefractive keratectomy (PRK). SETTING: Gazi University, Medical School, Department of Ophthalmology, Ankara, Turkey. METHODS: Between January 1995 and December 1997, 62 eyes had PRK to correct hyperopia. RESULTS: Nine eyes developed corneal iron ring 5 to 8 months (mean 6.25 months +/- 1.3 [SD]) after PRK for hyperopia. The rings persisted during the mean follow-up of 19 +/- 11.09 months. CONCLUSION: The ring-shaped iron deposition after PRK for hyperopia must be differentiated from the Fleischer ring. Our results suggest that the slitlamp findings of peripheral corneal iron deposition in hyperopic PRK patients correlate with achieved correction.

Acute corneal decompensation after silicone oil removal.

PURPOSE: To assess acute corneal decompensation after silicone oil removal in some aphakic eyes with clear corneas whose anterior chambers were completely filled with silicone oil for a considerable period of time. METHODS: Eight eyes of 8 patients who underwent vitrectomy and intraocular silicone oil injection were studied. All the eyes were aphakic and anterior chambers were completely filled with silicone oil. In all eyes, corneas were clear and no corneal finding indicating keratopathy was detected by slit-lamp microscopy before silicone oil removal. The mean silicone oil removal time was 4 months (range 2-7 months). A specular microscope was used for the evaluation of corneal endothelial changes and corneal pachometry was performed to observe corneal changes before and after the silicone oil removal in 5 eyes besides slit-lamp microscopy. The follow up period after silicone oil removal was 2-12 months (mean 6 months). RESULTS: In all eyes severe corneal stromal edema and clouding was detected in the first day following silicone oil removal. Increased corneal thickness was seen in all eyes. Decreased (at or below critical levels) corneal cell density was detected by specular microscopy before and after silicone oil removal. No significant improvement was observed during the follow up period. CONCLUSION: Eyes whose anterior chambers completely filled with silicone oil could be evaluated as clear corneas by slit lamp microscopy despite severe endothelial damage. We recommend that eyes with silicone oil in the anterior chambers should be monitored by a combination of slit-lamp microscopic examination and specular microscopy to determine the relative corneal endothelial tolerance to the silicone oil and endothelial damage. Early removal of the silicone oil can be considered when the retinal adhesion allows.

Effects of perfluorophenanthrene on the human corneal endothelium.

PURPOSE: To evaluate long term effects of perfluorophenanthrene (C12F24), a perfluorocarbon fluid, in the anterior chamber of the human eye, where residual perfluorophenanthrene was retained in the eye postoperatively. METHODS: Slit-lamp microscopic and specular microscopic examinations of 4 eyes of 4 patients were performed. All the eyes were operated for complicated retinal detachment and they were aphakic at the end of the operations. Mean follow-up period was 10 months (6-16 months). RESULTS: Perfluorophenanthrene was seen in the anterior chamber in the first or second day postoperatively as a single drop. In the third week, postoperatively, the first signs of splitting the perfluorophenanthrene (fish egging phenomena) was observed. There was no sign of corneal or anterior segment toxicity with the slit lamp microscopic examinations and the intraocular pressure was within normal limits during the follow-up period in all eyes. However, some structural changes of the corneal endothelium were shown by specular microscopy. Decreased endothelial cell density, a reversed illumination pattern in which the normally dark cellular boundaries appear bright and intracytoplasmic light reflecting bodies were signs of cellular damage at the contact sites whereas no significant changes were seen at non contact sites. CONCLUSION: Residual perfluorophenanthrene in the anterior chamber does not induce gross corneal damage or ocular inflammation, although structural changes indicating the damage of the corneal endothelium, can be shown by specular microscopy at the contact sites. Corneal endothelial changes seem to arise from a contact-dependent effect of the perfluorophenanthrene.

Aqueous transforming growth factor-beta-I levels in rabbit eyes after excimer laser photoablation.

Transforming growth factor beta (TGF-beta) plays an important role in anterior segment wound healing, by controlling the cell proliferation and differentiation, angiogenesis, extracellular matrix composition and mediating the immunosuppressive properties of the aqueous humor. The present study was undertaken to clarify the possible changes of aqueous humor TGF-betaI levels after excimer laser photoablation. Twenty-eight New Zealand rabbits were divided into four groups of 7 rabbits each. Group 1 served as control, the central 7 mm of corneal epithelium was removed in groups 2, 3 and 4. We performed 50-microm corneal photoablation in group 3, and 100-microm ablation in group 4. After 48 h we measured the TGF-betaI levels of the aqueous humor by ELISA method. The mean TGF-betaI value of the aqueous humor was found to be 162.94+/-13.73 pg/ml in the control group. Mechanical deepithelialization did not change the TGF-betaI levels of the aqueous humor (p > 0.05). There was no significant difference between the 50-microm photoablated group and the controls (p > 0.05), but the TGF-betaI levels of the 100-microm photoablated group were found to be significantly higher than those of both the control group and 50-microm photoablated group (p < 0.05). Many factors and cytokines may induce corneal haze and myopic regression after excimer laser photoablation; our study demonstrated that TGF-betaI is one of these factors and there is a positive correlation between the depth of corneal photoablation and aqueous TGF-betaI concentrations.

Fluorometholone-induced cataract after photorefractive keratectomy.

The use of topical corticosteroids following photorefractive keratectomy (PRK) is widespread. The major complications of potent corticosteroids are glaucoma and cataract formation; in order to decrease these complications, 0.1% fluorometholone administration is usually preferred after PRK. We report here a case of lens opacification which was induced by 0.1% fluorometholone administration after PRK in a period of 4 months. To our knowledge, this is the first reported case of 0.1% fluorometholone-induced cataract after PRK.