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

Clin Ophthalmol. 2010 Apr 26:4:315-9. doi: 10.2147/opth.s9870.


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.

Keywords: corneal topography; visual acuity.