A longitudinal study to evaluate effect of surgically induced astigmatism after phacoemulsification clear corneal incision placed in the steepest meridian on eyes with preexisting astigmatism

Abstract

Context: Surgically induced astigmatism (SIA) is the cause of poor postoperative vision even after uneventful cataract surgery. Aims: (1) To evaluate the effect of SIA after phacoemulsification clear corneal incision in the steepest meridian on the magnitude of preexisting astigmatism (PEA). (2) To map the magnitude of SIA by incisions in superior (S) and temporal (T) positions. Settings and Design: KLES Dr. Prabhakar Kore Hospital and Medical Research Centre (MRC), Belagavi, Karnataka. Longitudinal study. Subjects and Methods: The present 1-year study was conducted in the Department of Ophthalmology, KLES Dr. Prabhakar Kore Hospital and MRC, Belagavi, on patients undergoing cataract surgery during the period of January 1, 2014,-December 31, 2014. The patients undergoing phacoemulsification with PEA ranging from 0.5 D to 1.5 D were selected for the study to evaluate SIA after phacoemulsification clear corneal incision in the steepest meridian on the magnitude of the PEA. Statistical Analysis Used: Paired t -test was used to calculate mean SIA. Results: The result showed average SIA recorded was 0.54 ± 0.34 D with P P = 0.145). On taking temporal incision, the mean keratometric difference was 1.03 ± 0.96, which was statistically significant. On taking superior incision, the mean keratometric difference was 0.92 ± 0.95, which was statistically significant. Conclusions: Choosing the clear corneal incision site based on the preoperative steepest meridian significantly decreased keratometric astigmatism at the temporal and superior locations. As well as, temporal incision is evidently better than superior incision in minimizing SIA.