Changes in Corneal Curvature and Astigmatism After Phacoemulsification Surgery

Abstract

Background: This study aimed to investigate the relationship between anterior corneal curvature and astigmatism before and after phacoemulsification surgery.
Methods: A total of 90 eyes from 90 participants who underwent phacoemulsification with a 3.0 mm superior-temporal clear corneal incision were included in this longitudinal study. Each participant underwent a comprehensive ocular examination, including refraction and keratometry readings (k-readings) obtained using an automated keratometer on the IOL Master. Examinations were conducted preoperatively, on the first postoperative day, at one week, and four weeks postoperatively. The four-week postoperative refractive astigmatism was estimated and predicted with preoperative k-readings.
Results: The mean preoperative and postoperative refractive astigmatism was -0.74±0.49D and -0.36±0.18D, with a mean difference of -0.38±0.46D (p<0.001). The proportion of with-the-rule (WTR) astigmatism increased significantly at four weeks postoperatively (71.1%) compared to preoperatively (16.7%). Linear regression analysis showed that postoperative refractive astigmatism was not significantly influenced only by preoperative anterior k-readings obtained using the automated keratometer (?=-0.046; p=0.77).
Conclusions: A supero-temporal 3.0 mm clear corneal incision has shown stability in minimizing postoperative surgically induced astigmatism (SIA) in phacoemulsification cataract surgery. Postoperatively, posterior corneal curvature changes may attributes to surgically induced astigmatism which may be benefited by toric intraocular lens implantation (IOL) for better visual outcome.
Keywords: Auto refractometer; incision; keratometry-readings; phacoemulsification; surgically induced astigmatism.