The effect of ptosis surgery on corneal topography and aberrometry.

Abstract

Purpose: To evaluate the corneal topography and aberrometry and their changes following ptosis surgery in patients suffering from unilateral congenital blepharoptosis.

Methods: The study included 15 eyes of 15 patients with unilateral congenital blepharoptosis who underwent surgical correction through anterior levator resection. Shack-Hartmann wavefront sensor was employed to assess Zernike coefficients and root-mean-square. Computerized corneal topography, Orbscan and aberrometry were measured pre-and 3 months post-surgery in the healthy and ptotic eyes. Aberrometric changes were compared between patients with more than one diopter of astigmatism and subjects with less amount of astigmatism. Data were analyzed using the SPSS version 16. P < 0.05 was considered as significance level.

Results: Following anterior levator resection, the amount of astigmatism decreased. However, the difference was not statistically significant. Changes in topographic indices were not statistically significant. Regarding tomographic indices, the change in minimum keratometry was significant. The amount of change in total higher-order aberrations (HOAs) was not statistically significant. However, there was a decrease in the amount of third-order aberrations (vertical coma and vertical trefoil) which was statistically significant for vertical coma (-0.002 ± 0.001 vs. -0.08 ± 0.02 µm, P = 0.02). Comparing aberrometric changes in patients with more than 1 diopter astigmatism and less, there was a significant difference in the amount of HOA w/o Z400.

Conclusion: Surgical correction of ptosis could reduce the ocular aberrations, despite no significant change in astigmatism. Nonaxial high-order aberrations are mostly affected probably due to the meridional effect of ptosis on the cornea.