Long-term Course of Induced Astigmatism after Temporal Clear Corneal Incision in Cataract Surgery

Seo, J B; Joo, C K

Abstract

The purpose of the study was to evaluate long-term course of induced astigmatisms after temporal clear corneal incision according to preoperative keratometric astigmatisms. We analyzed cases of 116 eyes which were underwent phacoemulsification and foldable silicone posterior chamber lens implantation using 3.2 mmtemporal clear corneal incision. The subjects were divided into five groups: Group 1[against the rule > OR =1.25D], Group 2[ATR < OR =1.0D], Group 3[keratometric astigmatism =0D], Group 4[with the rule < OR = 1.0D] and Group 5[WTR > OR =1.25D] according to preoperative astigmatisms. Mean keratometric astigmatisms were 0.18+/-0.98D[ATR] preopertively, 0.36 +/-0.96D[WTR] at 2 months and 0.05+/-0.95D[WTR] at 1 year after operation. Mean surgically induced astigmatisms[SIAs] were 0.73+/-1.01D at 1 day, 0.50+/-0.79D at 2 months and 0.27+/-0.72D[WTR] at 1 year after operation. SIAs in group 1, 2 were 0.75+/-0.78D, 0.45+/-0.67D and in group 3, 4 and 5 were 0.08+/-0.66D, 0.02+/-0.70D and 0.06+/-0.86D[WTR] at 1 year after operation. SIAs in group 1, 2[ATR groups] were larger than group 4, 5[WTR groups] and the difference was statistically significant until 1 year after operation[p<0.05]. The results of this study indicates that temporal incision cataract surgery reduce keratometric astigmatism in preoperative ATR groups[group 1, 2]. SIAs in WTR groups[group 4, 5] were regressed to preopertive state at 1 year after operation. Therefore the patients who have preoperative WTR astigmatism lager than 1.25D seem to be needed change the location of incision in temporal clear corneal incision cataract surgery.