Effect of Cyclosporine A 0.05% on Human Corneal Epithelial Cells

PURPOSE: To evaluate the toxic effect of topical cyclosporine on cultured human corneal epithelium and to investigate the apoptotic response and cellular morphologic changes associated with cyclosporine in vitro. METHODS: Human corneal epithelial cells were exposed to a concentration of cyclosporine A (0.05%) for a period of 3, 5, and 10 minutes. MTT-based calorimetric assay was performed to assess the metabolic activity of cellular proliferation and lactate dehydrogenase (LDH) leakage assay for cytotoxicity. Apoptotic response was evaluated with flow cytometric analysis and fluorescence staining with Annexin V and propiodium iodide. Cellular morphology was evaluated by inverted phase-contrast light microscopy and electron microscopy. RESULTS: The inhibitory effect of human corneal epithelial cell proliferation and cytotoxicity showed a time-dependent response and had a significant effect when exposed for 10 minutes (P=0.04). The maximun response did not reach the leathal dose (LD)50. Apoptosis was seen in flow cytometry and apoptotic cells were demonstrated in fluorescent micrograph after being treated treating with cyclosporine A (0.05%). Human corneal epithelial cells were more detached from the bottom of the dish and damaged cells show degenerative changes like microvilli disappearance, vacuoles formation, and chromatin of the nuclear remnant condensed along the nuclear periphery. CONCLUSIONS: Cyclosporine A (0.05%) could be used without any significant toxic effect on human corneal epithelial cells except for exposure times longer than 10 minutes. Induction of apoptosis modulation may be one of the cyclosporine's mechanism for inhibiting cellular proliferation.

Diode Laser Endophotocoagulation

To evaluate the utility, safety, and reliability of diode laser endophotocoagulation in proliferative diabetic retinopathy, seventy-two consecutive eyes treated with diode endophotocoagulation were studied. A retrospective control group of 62 consecutive eyes undergoing vitrectoiny with argon laser endophotocoagulation was also studied. Minimal period of follow-up was 3 months. Final visual acuity was improved in 44 eyes (61.1%), and was 5/200 or better in 45 eyes (62.5%) with diode endophotocoagulation. In comparison, final visual acuity was irnproved in 40 eyes (64.5%), and was 5/200 orbetter in 37 eyes (61.6%) for argon endophotocoagulation. A rupture of Bruch`s rneinbrane was developed in 2 eyes with diode laser treatment, and a retinal hemorrhage was developed in one eye with argon laser treatment. No statistically significant difference was found between the two groups regarding the rate of visual iniprovement and final visual results. This study supports the conclusion that the diode laser is as effective for the endophotocoagulation in proliferative diabetic retinopathy as argon laser treatment.

Analysis of Abnormal Heal Posture and Surgical Results in the Patients with Duanes Retraction Syndrome

We evaluated retrospectively the clinical records of 46 cases of Duanes retraction syndrome. The purpose of this study is to demonstrate a clinical characteristics of this syndrome and improvement of abnormal head posture and degree of deviation in 14 cases undergoing operation. Unilateral manifestation was in 42 cases and 4 cases were involved bilaterally. Left eye was involved predominantly in 29 cases (63.0%). The frequencies analyzed according to Hubers classification were that Type I was 64.3%, Type II 7.1%, and Type III 28.6% in unilateral cases. Of unilateral cases, compensatory face turn was exhibited in 65.2% of Type I, 100% of Type II, and 60.0% of Type III. In primary position, 44.4% of Type I had esodeviation, and 100% of Type II ad 83.3% of type III had exodeviation. The major concerns of most patients or their parents were the correction of strabismus and gaze limitation, but they hardly recognized abnormal head posture. The correction of abnormal head posture and strabismus was achieved in 78.6% postoperatively.