CHANGE IN CORNEAL ASTIGMATISM AFTER PTERYGIUM EXCISION USING BARE SCLERA TECHNIQUE

Abstract

Objective: This study aimed to evaluate and compare the changes in corneal astigmatism following pterygium excision using the bare sclera and conjunctival autograft techniques.

Methods: The study was conducted as a prospective comparative study carried out at the Combined Military Hospital in Gujranwala in the period between March and September 2024. A total of ninety patients (45 per group) with primary nasal pterygium, were randomly divided into two groups where they were expected to undergo excision with the bare sclera approach or conjunctival autograft method. Uncorrected and best-corrected visual acuity, keratometry values with the Topcon RM 8000B autorefractometer, and slit-lamp test were used as pre- and postoperative measures.

Results: The two groups of surgical individuals showed a significant improvement in corneal astigmatism postoperative (p < 0.05). The range of the mean change of the astigmatism in the bare sclera group (3.28 with 1.01 SD to 1.17 with 0.88 SD) was higher than the conjunctival autograft group (3.34 with 1.07 SD to 1.74 with 1.01 SD). There was a positive significant correlation (r = 0.712, p < 0.001) between the size of preoperative pterygium and the level of astigmatism. 

Conclusion: The bare sclera technique was shown to have better refractive results compared with the conjunctival autograft procedure with a stronger and quicker reduction in corneal astigmatism in the first three months after surgery. The bare sclera method has low cost, shorter operation time and is very easy to perform, thus it has been found to be still a useful surgery in ophthalmic centres with limited resources and high volume, especially when used together with proper patient selection and good follow-up methods in order to check recurrence