Purpose: To identify the exact time point during after following pterygium excision with a modified technique of sutureless, glueless limbal-conjunctival autograft, when stabilization of the change in corneal curvature is achieved; correlate size of pterygium with uncorrected visual acuity and astigmatism at baseline, and assess changes in these parameters postoperatively over time.
Methods: This prospective study longitudinally assessed 30 eyes of 30 north Indian adults with primary pterygium encroaching upon ≥1 mm of the cornea pre- and postoperatively at 1 week and then monthly for 4 months, recording uncorrected (UCVA) and best-corrected logMAR visual acuity, astigmatism and keratometry. Results were analyzed using ANOVA, Mauchly's test of sphericity with Greenhouse-Geisser correction, and post-hoc test using Bonferroni correction. Pearson's correlation coefficient r > 0.5 was considered clinically significant, and P < 0.05 statistically significant.
Results: Pterygium size was well correlated with pre-operative astigmatism (r = 0.867, P < 0.001) and pre-operative UCVA (r = 0.856, P < 0.001). There was mean improvement of 0.43 logMAR units of visual acuity (P < 0.00001), a mean increase of 0.79D of keratometric value for the flatter meridian (P < 0.00001) and a mean reduction of 2.00D of astigmatism (P < 0.00001). At 2-month follow-up, the keratometric value for the flatter meridian approached the final keratometric reading at 4 months such that the difference was not significant (t = 1.185, P = 0.245). There were no significant complications or recurrence during the follow-up period.
Conclusion: Pterygium excision with modified autograft reduced corneal astigmatism and improved visual acuity comparable to classical technique. Alteration in corneal curvature stabilizes 2 months after surgery, when spectacle correction can be given to patients.
Keywords: Astigmatism; autologous fibrin tissue adhesive; corneal topography; pterygium surgery; visual acuity.