COMPARISON OF POST-SURGICAL CORNEAL ASTIGMATISM WITH PHACOEMULSIFICATION AND SMALL INCISION CATARACT SURGERY

Abstract

Background: Cataract, characterized by opacification of the crystalline lens, remains a leading cause of reversible blindness worldwide. Surgical intervention is the only effective treatment, with modern techniques shifting from large limbal incisions to smaller scleral approaches to improve wound healing and minimize surgically induced astigmatism. Comparative evaluation of incision size and position across surgical modalities is essential to optimize refractive outcomes and ensure faster visual rehabilitation.

Objective: To compare post-surgical corneal astigmatism following phacoemulsification and manual small incision cataract surgery (SICS), focusing on incision position and incision length.

Methods: A longitudinal study was conducted at LRBT Hospital, Lahore, between September 2022 and May 2023. A total of 140 patients aged 45–70 years were enrolled using non-probability convenience sampling. Participants were divided into two main groups: 70 underwent phacoemulsification and 70 underwent SICS. Each group was further subdivided into two subgroups of 35, based on incision position (superior or temporal) and incision length (1.75 mm or 2.75 mm). Visual acuity was assessed using a LogMAR chart, while corneal astigmatism was measured pre- and postoperatively using an autorefractometer and keratometer. Follow-up assessments were performed on Day 1, Week 1, and Week 6 post-surgery. Data were analyzed using Friedman’s and Mann–Whitney U tests in SPSS version 24.

Results: Baseline mean visual acuity for the phacoemulsification group was 0.831±0.199 D, which improved to 0.467±0.218 D on Day 1, 0.353±0.184 D at Week 1, and 0.226±0.152 D at Week 6 (Friedman’s test=177.138, p=0.00). For the SICS group, baseline vision was 0.884±0.178 D, improving to 0.544±0.260 D, 0.437±0.228 D, and 0.280±0.196 D respectively (Friedman’s test=181.158, p=0.00). Mean cylindrical error in phacoemulsification decreased from 0.831±0.199 D at baseline to 0.182±0.914 D at Week 6 (p=0.00), while in SICS it decreased from 0.831±0.199 D to 0.136±0.962 D (p=0.000). Comparisons by incision length revealed no significant difference at 1.75 mm (p>0.05), whereas at 2.75 mm phacoemulsification showed a significantly lower cylindrical error (p=0.007).

Conclusion: Both phacoemulsification and SICS produced significant improvements in visual acuity and reductions in corneal astigmatism. Phacoemulsification offered faster rehabilitation and lower astigmatic error with larger incisions, while SICS demonstrated comparable outcomes at smaller incision sizes. Given its affordability and effectiveness, SICS remains a practical alternative in resource-limited settings.