Scleral tunnel based sutureless extracapsular cataract extraction: An approach to astigmatic correction in soft cataracts of nuclear sclerosis grade 1

Abstract

Objectives: A study to see if scleral tunnel based sutureless extracapsular cataract extraction with superior quadrant approach can correct pre-existing corneal astigmatism in soft cataracts of non-structural protein 1 (NS1) grade nuclear sclerosis in patients of younger age profile having “with-the-rule” pattern of corneal astigmatism. Material and Methods: 47 eyes of 41 patients who underwent scleral tunnel based sutureless extracapsular cataract extraction were taken as the study group and a second group of 44 eyes of 38 patients who underwent clear corneal incision based phacoemulsification surgery formed the control group. Soft cataracts of NS1 grade nucleus having “with-the-rule” corneal astigmatism were included in the study. Keratometry measurements were done preoperatively and at 6 weeks post-operative follow-up by Zeiss IOLMaster. Results: Sutureless scleral tunnel based extracapsular cataract extraction was found to neutralize pre-existing corneal astigmatism if it was in range of 1.0–1.5 D. It was also found to change the pattern of astigmatism from “with-the-rule” to “against-the-rule” if the pre-operative astigmatism was in the range of 0.5–1.0 D with little change in the absolute value of the astigmatism. Conclusion: Patients with pre-existing with-the-rule corneal astigmatism undergoing scleral tunnel based sutureless extracapsular cataract extraction had reduced corneal astigmatism. Phacoemulsification, on the other hand, was found to be an astigmatically neutral surgery.