Título

THE IMPACT OF PTERYGIUM EXCISION ON CORNEAL ASTIGMATISM.

Objetivo

To compare the corneal astigmatism before and after the excision of pterygium (Pt) and also to determine the correlation of pterygium grade with the postoperative corneal astigmatism. STUDY DESIGN: Cross-sectional interventional study.

Método

Twenty-five patients underwent pterygium excision. Pre-operatively Snellen visual acuity, manifest refraction and slit lamp examination was done. The grade of the pterygium was recorded 2 or 3 by projecting a horizontal slit lamp beam from the limbus to the apex. Twenty patients with grade 2 and 5 with grade 3 patients were selected. The surgeries were performed following the same techniques of asepsis, antisepsis and with the following surgical technique: topical anesthesia, associated with subconjunctival anesthetic infiltration at the Pt site; delamination of the lesion head with scalpel blade 15 to the limbus and removal of the head along with adjacent fibrovascular tissue; which was sutured with unabsorbed braided wire Sedal 7-0® Keratometry was performed with an automated topography. Keratometric data was recorded pre-operatively and at 30 days postoperatively. Wilcoxon signed rank test was used for comparing the pre-operative and the postoperative corneal astigmatism. Spearman's rank order was calculated to observe correlation of pterygium grade with the preoperative astigmatism.

Resultado

The mean difference between (k2-k1) of 3 mm before surgery was 3,01 ± 3,57 and after 2,21 ± 2,1; The mean difference between (k2-k1) of 5 mm before surgery was 3,74 ± 3,86 and after 2,17 ± 2,45; The mean difference between (k2-k1) of 7 mm before surgery was 2,28 ± 3,05 and after 1,76 ± 1,52. Only there was a statistically significant correlation between the preoperative astigmatismo (7mm) and the pterygium grade (rs = -0.48, p = 0.013).

Conclusão

Pterygium excision caused significant reduction in corneal astigmatism. The grade of pterygium induce corneal astigmatism.