Surgically induced astigmatism comparative study between superior versus superotemporal incision in small incision cataract surgery

Introduction: Cataract surgery incisions have been known to influence astigmatism. It has been found by keratometric measurement, the degree of induced astigmatism was significantly less in superolateral compared to superior incision and the variability of astigmatism was also less. In view of this, we have made an effort to compare the astigmatism following conventional superior scleral incision and superotemporal scleral incision with posterior chamber intraocular lens implantation. Objectives: Of the study were to compare and analyse the astigmatic profile produced by superior scleral incision v/s superotemporal scleral incision and its decay over a period of 6 weeks and the post- operative astigmatic profile in patients having pre- operative against the rule astigmatism Materials and Methods: It was a prospective cross-sectional study done on 96 patients who underwent suture less small incision cataract surgery during the period of 2 years (2014-2016) All patients with cataract were included. All the surgeries were performed by a single surgeon. Results: Most of the patients were in the age group of 50-60 years. Follow-up showed that 18.8% patients undergoing superior scleral incision had >2.5 D astigmatism at any given time, whereas none of the patients in superotemporal group showed such high induced astigmatism. On the contrary <1D astigmatism was seen in 37.5% patients undergoing superior scleral incision and in 85 % patients in Superotemporal group.6 weeks follow up of these patients showed significant difference in astigmatism. Conclusion: Surgically induced astigmatism in superotemporal incision is significantly less compared to superior incision in SICS. Superotemporal incision did not show significant post op against the rule drift. It has the added advantage of being the incision of choice in deep set eyes and in situations where filtration surgery may be required at a future date.