Change of Corneal Thickness after LASIK and Relationship be tween Corneal Thickness and Preoperative Factors

We analysed the relationship between preoperative factors and changes of corneal thickness after LASIK.Between January 1997 and October 1998, 124 eyes underwent LASIK procedure using VISX STAR at Kangnam's St. Mary's hospital.In group 1, 39 eyes had corneal thickness 50 micrometer or more after preoperative corneal thickenss was substracted with postoperative thickness.As control group, 33 eyes had the difference of corneal thickness 0 -5 0 micrometer or less.The each difference was calculated at 1 wk, 1 month, 6 months, 1 year postoperatively.We evaluated the preoperative factors, such as corneal thickness, spherical equivalent, corneal keratometer.The attempted correction for refractive errors was determined by cycloplegic refraction.In group 1, the difference in corneal thickness was 77 +/-2.5 micrometer at 1 week.58 +/-1.4 micrometer at 2 months, 57 +/-1.2 micrometer at 6 months and 58 +/-1.4 micrometer at 1year postoperatively. These results statistically greater than those of control group.And the more spherical equivalent, the thinner corneal thickness, the more difference in corneal thickness was, which was statistically signifi-cant comparing with group 2 (P<0.05).But, preoperative keratometry and the difference in corneal thickness was not significant between two groups (P=0.64).

Clinical Evaluation of Epiblepharon and Congenital Entropion

We retrospectively reviewed the sex distribution, age at oepration, chief complaints, peroperative and postoperative refractive errors, and corrected visual acuity in 160 previously operated patients to evaluate the clinical manifestations, reractive error, frequency of amblyopia, age at operation, and the postoperative factors affected by the operation of epiblepharon and congenital entropion itself that influence visual acuity and refractive error. The average age at operation was 7.9 years. The chief complaint was ocular discomfort, followed by visual disturbance, photophobia, eyelid rubbing and epiphora. One hundred thirty-three wyws(41.6%) whose preoperative corrected visual acuity was below 0.6 had a mean visual acuity of 0.7. Ninety-five eyes (29.7%) were preoperative myopes above -1.0D, 77 eyes(24%) were hyperopes above +1.0D, and 163 eyes were astigmatic above -1.0D. Twenty-two out of 76 eyes who were followed up for more than one year had a corrected visual acuity of below 0.6. The difference between the older and less than 7 years groups was significantly not significant. Astigmatic changes were not statistically different at any age group. However, the mean significantly visual acuity at postoperative one year was 0.73, which was significantly different from the preoperative value(P=0.006). In conclusion, concurrent postoperative glasses correction and amblyyopia therapy is indicated because the incidence of refractive errors and amblyopia is higher in epiblepharon and congenital entropion.

The Effect of Transscleral Diode Laser Cyclophotocoagulation in Refractory Glaucoma

The purpose of this study was to validate the efficacy of transscleral diode laser cyclophotocoagulation (CPC)procedure in refractory glaucoma cases for which conventional medical or surgical filtering procedures had failed or were thought to have a poor likelihood of success. Thirty-eight eyes of 38 consecutive patients with refractory glaucoma received transscleral diode CPC. Patients were followed for a mean of 5.5 months. We reviewed available data at preoperative state and at 1 day, 1week, 1 month, 2 months and 4 months postoperatively. Data analyzed were visual acuity, intraocular pressure(IOP)and postoperative complications. There was a statistically significant decrease in IOP at postoperative 1day, 1 week, 1 month, 2 months and 4 months compared with preoperative IOP. Postoperative complications were hyphema in 4 eyes and fibrinousuveitis in 1 eye but all of these complications were controlled with medical treatment. We concluded that transscleral diode CPC could be a good treatment proce-dure for the IOP control in refractory glaucoma cases.

Results of Phacoemulsificatin with PCL Implantation in Post-trabeculectomy Eyes

We evaluated the clinical results of phacoemulsification and posterior chamber lens implantation in posttrabeculectomy eyes. 26 eyes operated during Jan. 1990 to Dec.1995 were evaluated retrospectively with preoperative and postoperative visual acuity, intraocular pressure(IOP) and antiglaucomatous agent usage.The cataract operations were done by clear corneal incisions avoiding the filtering bleb sites. The average interval between trabeculectomy and cataract surgery was 25 months. From a total of 26 eyes 11 had the diagnosis of primary open angle glaucoma(POAG) and 12 eyes chronic angle closure glaucoma(CACG). The preoperative visual acuity was 0.3 or less in 53.8%, and the postoperative visual acuity was 0.4 or better in 57.7%. The preoperative and postoperative IOPs were 14.4+/-4.3mmHg and 15.3+/-4.6mmHg respectively, showing a slight increase. Filtering bleb failure was observed in one eye in which trabeculectomy was formed twice. Antiglaucomatous agent usage decreased to 8 cases from an initial 10 cases. The preoperative IOP of the 8 cases was 17.3+/-5.1mmHg, while it was 13.1+/-3.3mmHg in the 18 cases in which the IOP was controlled without treatment. There was a significant difference between the two(P=0.03). There was a significant relationship between preoperative and postoperative antiglaucomatous agent usage(P=0.01). Taken individually, POAG showed a greater incidence of postoperative antiglaucomatous agent usage than CACG, but was insignificant(P=0.56).