The effect of pterygium surgery on contrast sensitivity and corneal topographic changes

Abstract

Purpose: To investigate the effect of pterygium surgery on corneal topography and contrast sensitivity. Patient and methods: The IRB approved this prospective, nonrandomized, self-controlled study. Computerized videokeratography (Orbscan II) was performed in 36 patients with primary pterygia, both before and 1 month after pterygium excision with limbal-conjunctival autografting. The topographic parameters were compared. Spatial contrast sensitivity testing was performed using VCTS 6500. Differences between preoperative and postoperative values were evaluated statistically. Results: The mean Sim K astigmatism and irregularity index, significantly decreased after pterygium surgery. The mean refractive power significantly increased after the operation. The with-the-rule astigmatism induced by pterygium became against-the-rule astigmatism after pterygium removal (P = 0.041). The contrast sensitivity of 6, 12, and 18 cycles per degree, significantly increased from 1.55 ± 0.28, 0.97 ± 0.47, and 0.29 ± 0.16 to 1.72 ± 0.18, 1.21 ± 0.44, and 0.65 ± 0.48, respectively (P = 0.007, < 0.001, < 0.001, respectively). Conclusions Pterygium surgery significantly reduces corneal topographic astigmatism and improves contrast sensitivity. © 2010 Oh and Wee, publisher and licensee Dove Medical Press Ltd.