Evaluation of Efficacy of Pterygium Excision on Ocular Higher-order Aberrations

Abstract

Background: Pterygium causes visual disturbance due to ocular surface irregularity. The convenient method to investigate this irregularity is measurement of ocular aberration. The aim of this study to investigate the impact of pterygium excision with conjunctival autograft together with corneal polishing on ocular higher-order aberrations (HOAs). Methods: This study was performed on 34 patients with primary nasal pterygium who had an indication for surgical excision in November 2013. All patients underwent a detailed ophthalmologic examination preoperatively and at the third postoperative months. Pterygium excision was performed by the same surgeon. Corneal topography and ocular higher-order aberration were measured by ITRACE. Results: Numerous parameters including mean value cylinder and spherical refractive error, visual acuity, root mean square values of total HOAs were found to be significantly improved at 3 month after pterygium surgery. There was significant difference between preoperative and postoperative mean refractive cylinder (- 6.77 ±1.08 diopter (D) vs. 2.25 ± 0.34 diopter (D), respectively, P < 0.0001). Log Mar best corrected visual acuity (0.11±0.03) was significantly higher than preoperative values (0.04±0.02)(p<0.001) . Preoperative mean refractive sphere was 4.92±0.79 diopter (D) which was significantly higher than postoperative refractive sphere 0.66±0.41 diopter (D) (P< 0.0001). All parameters (Total, Lo total, Defocus, Astigmatism, Coma, Trefoil: P<0.001 and Ho total: P=0.001 and secondary: P=0.04) except for total spherical aberration (P = 0.38) were found to be lower when compared with the preoperative values.. None of the patient harbor against the rule astigmatism preoperatively and a significant scope of with the rule cases changed to oblique astigmatism at 3 month which statistically significant (P<0.001). Conclusion: Pterygium excision can significantly improve visual acuity and most of the pterygium-induced HOAs.