Changes in Astigmatism and Visual Acuity after Pterygium Excision in the Ashanti Region of Ghana

Abstract

Background: Pterygium is a conjunctival subepithelial fibrovascular growth commonly occurring in the inter-palpebral conjunctiva nasally or temporally. It tends to grow over the cornea, leading to visual impairment due to various factors, including astigmatism. Methods: This was a prospective, multi-centered, hospital-based, interventional study carried out within 12 months in three eye centers in the Ashanti region of Ghana. One hundred eyes of 100 adults (≥18 years) with primary pterygia were recruited. Operated eyes had measurements of uncorrected visual acuity (UVA), aided visual acuity (AVA), and keratometry readings (K-readings) before pterygium excision with conjunctival autograft (CAG), 2 weeks after surgery, and 6 weeks after surgery. Results: The mean age of patients was 47.1±11.5 years. The mean pre-operative astigmatism was 5.0±5.9 D. The mean astigmatism values at 2 and 6 weeks post-operatively were 1.7±1.5 and 1.3±1.0 D, respectively. Eighty-nine eyes had AVA ≥6/12 (0.11 mean logMAR) before surgery, whereas 97 eyes had AVA ≥6/12 (0.02 mean logMAR) 6 weeks after surgery, and the increase was statistically significant. Conclusion: Pterygia excision with CAG leads to an approximately fourfold reduction in mean pterygium-induced astigmatism by 6 weeks after surgery.

Keywords

• pterygium
• astigmatism
• visual outcomes
• visual acuity