Assessment of the corneal high-order aberration changes after pterygium surgery

Corneal high-order aberrations due to pterygium have a significant impact on patients' visual quality. This study aims to assess changes in corneal high-order aberrations following pterygium surgery.

This hospital-based prospective study included 51 eyes of 51 patients with primary pterygium who underwent pterygium excision with conjunctival autograft. Corneal topography and ocular high-order aberrations (HOA) were measured using corneal topography and aberrometry scans with a Sirius Scheimpflug-Placido topographer, both preoperatively and 6 weeks postoperatively. These values were derived for both 3 and 5 mm pupillary diameters using Zernike polynomial expansion. The relative risk of residual postoperative aberrations was assessed in relation to increasing pterygium size.

The mean age of patients enrolled in the study was 40.3 ± 7.4 years. The root mean square value of total HOA significantly decreased at 6 weeks after uneventful pterygium surgery. Excision of pterygium significantly reduced all parameters (coma: 95% CI, p < 0.05; trefoil: 95% CI, p < 0.05; quadrafoil: 95% CI, p < 0.05), with trefoil being the main contributor. Astigmatism values also showed a significant postoperative reduction. In 15.9% of patients, preoperative "with-the-rule astigmatism" changed to postoperative "against-the-rule astigmatism." A notable increase in the relative risk of residual postoperative HOA was observed when the pterygium length exceeded 4 mm.

Pterygia are associated with corneal higher-order aberrations, particularly trefoil, which were largely eliminated by surgery. Earlier excision of pterygia reduces the likelihood of significant residual aberrations.