Effect of cysteine in transgenic mice on healing of corneal epithelium after excimer laser photoablation.

PURPOSE: To evaluate the role of prepared cysteine per os in corneal epithelial healing in transgenic mice (B6(A)-Rpe65rd12/J) after excimer laser photoablation. MATERIALS AND METHODS: In our prospective case series, 60 eyes of 30 mice had uneventful bilateral excimer laser photoablation. A first group, composed of 15 mice, received standard topical post-operative therapy with tobramycin, diclofenac and dexamethasone eyedrops, plus cysteine 5 mg 5 microg/10 microl phosphate-buffered saline (3 times a day for 1 week) per os or until corneal re-epithelialization was complete. The control group of 15 mice received standard post-operative therapy plus placebos. The mice were monitored daily, commencing the day after surgery, for 7 days to evaluate the corneal re-epithelialization rate using a video slit-lamp camera with a cobalt blue light. The mean diameters of corneal wounds were measured. Videotaped images were recorded and analysed by computer planimetry. RESULTS: All the eyes of the mice treated with cysteine healed completely by day 5 after surgery, with a mean re-epithelialization time of 92 +/- 10 h (SD); the mean re-epithelialization time was 125 +/- 8 h in eyes that received the placebo. There were no statistically significant differences between the 2 groups in corneal haze presentation during follow-up, perhaps because the time period was too brief (7 days). However, corneal clarity in the study group was greater than in the control group, as shown on slit-lamp biomicroscopy. No side effects or toxic effects were documented. CONCLUSIONS: These data suggest that cysteine significantly accelerates epithelial healing after excimer photoablation. A further clinical study should be performed to confirm the results obtained in this study, and the long-term efficacy of cysteine in preventing corneal haze.

Effect of cytochrome c peroxidase on the corneal epithelial healing process after excimer laser photo-ablation in transgenic mice.

AIM: To evaluate the role of commercially prepared cytochrome c peroxidase eye drops in corneal epithelial healing of transgenic B6(A)-Rpe65rd12/J mice after excimer laser photo-ablation. MATERIALS AND METHODS: In our prospective animal series, 72 eyes of 36 mice had uneventful bilateral excimer laser photo-ablation. In each mouse, one eye received standard topical postoperative therapy with tobramycin, diclofenac, and dexamethasone eye drops plus cytochrome c peroxidase eye drops (two drops three times a day for 1 week or until corneal re-epithelialization was complete, corresponding to 15,000 IU/day). The fellow eye served as the control and received standard postoperative therapy plus placebo. The mice were monitored daily, commencing on the day after surgery, for 7 days to evaluate the corneal re-epithelialization rate using a video slit lamp camera with cobalt blue light. The mean diameter of the corneal wounds was measured. Videotaped images were recorded and analyzed by computer planimetry. RESULTS: All eyes treated with cytochrome c peroxidase eye drops healed completely before day 5 after surgery, with a mean re-epithelialization time of 92 +/- (SD) 10 h; the mean re-epithelialization time was 121 +/- 8 h in the eyes receiving placebo (p < 0.05). There were no statistically significant differences between the two groups in corneal haze presentation during the follow-up period (p = 0.70), perhaps because the observation period was too short (7 days). However, the corneal clarity, on slit lamp biomicroscopy, in the study group was higher than that in the control group. No side effects or toxic effects were observed. CONCLUSIONS: These data suggest that cytochrome c peroxidase significantly accelerates epithelial healing after phototherapeutic keratectomy. Further clinical studies should be performed to prove the results obtained in this study and the long-term efficacy of cytochrome c peroxidase to prevent corneal haze.

Tamoxifen retinopathy: does it really exist?

BACKGROUND: Tamoxifen retinopathy is known to be an adverse effect of high-dose tamoxifen treatment. Evidence of ocular toxicity at lower doses is less convincing: the aim of this study was to assess the prevalence of the above-mentioned retinopathy in a population treated with low-dose tamoxifen. METHODS: One hundred and twenty-nine women treated with low-dose tamoxifen (20 mg/day) were examined. Visual acuity measurement, slit-lamp biomicroscopy and fundus examination were performed. Patients were reexamined after 6-12 months. RESULTS: Refractile retinal opacities, similar to those previously described as tamoxifen retinopathy, were observed in four patients (prevalence 3.1%; mean duration of therapy 806 days). None of them revealed corneal opacities, papillary and/or macular edema, or visual impairment. The ophthalmoscopic aspect did not change after a mean follow-up of 215 days, although one of these patients had interrupted tamoxifen intake. Statistical analysis (Student's t-test) did not reveal any difference between patients with and those without refractile retinal opacities as far as age, treatment duration and ERG values were concerned. An early hyperfluorescence, reminescent of cuticular drusen, was demonstrated by fluorescein angiography in all four cases. CONCLUSIONS: The present study would seem to confirm that low-dose tamoxifen may induce retinal toxicity in a low proportion of patients, but we cannot be certain that the refractile retinal opacities observed are really caused by tamoxifen, as differentiation from age-related macular degeneration with cuticular drusen appears nearly impossible.

Pseudoexfoliation syndrome: a cohort study on intraoperative complications in cataract surgery.

Our aim was to determine the rate of intraoperative complications induced by pseudoexfoliation syndrome (PSX) in cataract surgery. We report our experience regarding 1,052 consecutive patients who underwent phacoemulsification. Exact logistic regression was used to examine the role of PSX in intraoperative complications. Odds ratio for intraoperative complications (vitreous loss, capsular break, zonular break) was estimated to be 5.1 for PSX present as compared to when it is absent. PSX was associated with a statistically significant increase in intraoperative complications during cataract surgery (p<0.0001).

Brain pathology and strabismus.

If we consider the complex and articulate organization of the oculomotor neural system, ie, infranuclear, nuclear, internuclear, and supranuclear levels, how many neuronal structures are implicated and their widespread localization in the central nervous system, and if we understand the various relationships within the oculomotor system and with other cerebral structures, we may easily realize that cerebral diseases and oculomotor disturbances are tightly and reciprocally connected. Many diseases may be associated with ocular movement impairment, sometimes acting on different sites of oculomotor organization. These alterations may have a clear pathophysiologic meaning and a relevant topographic localizing value, otherwise correlations and mechanisms are simply hypothetical. Last but not least for conceptual relevance are the modifications of neuronal anatomy and physiopathologic mechanisms induced by the strabismus. In the past year many articles have been published that analyze the relationships and the pathogenetic role of cerebral anomalies in the context of strabismus syndromes. Of outstanding interest is the proof of cortical and subcortical neural stations' plasticity, and the evidence of a cerebral anatomophysiologic basis of strabismus and amblyopia. In this context the midbrain, pontine, and brain stem nuclei and neuronal organizations have a peculiar importance. We will try to systematically expose, even if briefly, the main contributions in this area.

Effects of oxygen-ozone therapy on age-related degenerative retinal maculopathy.

The effects of oxygen-ozone therapy on 20 patients affected by age-related degenerative maculopathy have been studied. Visual acuity and eye fluorangiography were the parameters used in order to evaluate the efficacy of the therapy. Medical ozone was administered intravenously according to the technique called "ozonized major autohemoinfusion", the total amount of ozone ranging from 1,500 to 2,000 micrograms per session for a 4 months period. The results have indicated that the majority of patients showed an improvement of their ocular condition, suggesting continuation of this type of investigation on a larger group of people.