Pre-Operative and Post-Operative Evaluation of Corneal Astigmatism after Pterygium Operation Using Crescent Knife

Abstract

BACKGROUND Smoothening of the corneal surface after primary pterygium excision is a costeffective, time saving technique to treat anterior corneal scars and high corneal astigmatism related to pterygium. We wanted to compare the visual acuity and astigmatism before and after pterygium operation using crescent knife. METHODS This prospective follow up study was conducted on a total of 40 patients with primary pterygium inducing visually significant astigmatism. Visual acuity, K reading, astigmatism were recorded before surgery and at 1 week, 6 weeks and 12 weeks following surgery whereas corneal clarity was assessed post operatively. The pterygium remnant tissue over cornea was polished using a crescent knife. Data was compiled using MS Excel and analysed using SPSS version 2.0. RESULTS Mean age of patients was 48.88 ± 11.72 years and about 30 (75%) of study population was composed of females and only 25% patients were male. Mean Best Corrected Visual Acuity (LogMAR) preoperatively was 0.22 ± 0.16, whereas that at 12 th week was 0.11 ± 0.09 and the improvement was statistically significant. Also a significant improvement in flat K and K average and corneal clarity at various follow up was observed (p<0.01) the mean astigmatism also reduced significantly (p<0.01). CONCLUSIONS There is a significant improvement in vision and corneal clarity following pterygium excision and corneal polishing using crescent knife. Also, corneal polishing led to significant reduction in astigmatism and improvement in flat and average K readings.