Material and methods: Patients with nasal, primary pterygium were included. Exclusion criteria were a history of previous ocular surgery, recurrent pterygium, anterior segment pathologies that affect corneal aberrations and refraction such as keratoconus, corneal scarring. Anterior segment photos of the patients were taken in primary position before surgery (Haag-Streit BQ 900 imaging, Koeniz, Switzerland). The length and area of pterygium on the cornea were calculated from by AdobePhotoshop 6.0.1 programme. Topographic fi ndings and HOAs data were evaluated preoperatively and one month postoperatively. Topographic astigmatism and HOAs [coma, trefoil, spherical aberration, higher order root mean square (HOA-RMS) and total RMS] of the anterior surface of the cornea were evaluated with Pentacam HR (Oculus OptikgeräteGmbH).

Results: Thirty seven eyes of 37 patients were enrolled. The mean age was 37.9±7.3 (17-56 years), the pterygium length was 3.43±1.17 mm (2.10-4.10 mm) and the pterygium area was 6.43±2.14 mm2 (3.85-7.93 mm2). Decrease in astigmatism (p<0.01), coma (p<0.01), HOA-RMS (p=0.01) and total RMS (p=0.01) after surgery were signifi cant but trefoil (p=0.64) and spherical aberration (p=0.22) were not. Improvement in the astigmatism, coma, HOA-RMS and total RMS after surgery had a positive correlation with pterygium length (r =0.712, r =0.624, r =0.562, r=0.813 respectively) and pterygium area (r=0.568, r=0.524 r=0.483, r=0.623; respectively). However, the correlation with pterygium length was stronger than with the pterygium area.

Conclusion: Pterygium surgery provides substantial improvement on corneal astigmatism and aberrations thus increases the visual quality. Keywords : Pterygium surgery, corneal astigmatism, corneal aberration