Comparison of surgically induced astigmatism in various incisions in manual small incision cataract surgery

AIM: To determine the surgically induced astigmatism (SIA) in Straight, Frown and Inverted V shape (Chevron) incisions in manual small incision cataract surgery (SICS). METHODS: A prospective cross sectional study was done on a total of 75 patients aged 40y and above with senile cataract. The patients were randomly divided into three groups (25 each). Each group received a particular type of incision (Straight, Frown or Inverted V shape incisions). Manual SICS with intraocular lens (IOL) implantation was performed. The patients were compared 4wk post operatively for uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA) and SIA. All calculations were performed using the SIA calculator version 2.1, a free software program. The study was analyzed using SPSS version 15.0 statistical analysis software. RESULTS: The study found that 89.5% of patients in Straight incision group, 94.2% in Frown incision group and 95.7% in Inverted V group attained BCVA post operatively in the range of 6/6 to 6/18. Mean SIA was minimum (-0.88 +/- 0.61D x90 degrees) with Inverted V incision which was statistically significant. CONCLUSION: Inverted V (Chevron) incision gives minimal SIA.