Comparison of Corneal Astigmatism Before and After Pterygium Excision and Associated Factors Among Patients Attending the Ophthalmology Department of St. Paul’s Hospital Millennium Medical College, Addis Ababa ,Ethiopia,2026.

Abstract

ABSTRACT. Background: Pterygium is a wing‑shaped fibrovascular growth of the conjunctiva that extends onto the cornea, often leading to corneal distortion, astigmatism, and reduced visual acuity. Although surgical excision remains the mainstay of treatment, recurrence and inconsistent outcomes regarding corneal astigmatism reduction remain challenges. In Ethiopia, the prevalence of pterygium is high, particularly among outdoor workers exposed to ultraviolet (UV) radiation, yet limited data exist on the effect of excision on astigmatism and vision in Addis Ababa. Objective: To assess the mean change in corneal astigmatism before and after pterygium excision and to identify associated factors among patients attending the ophthalmology department at St. Paul’s Hospital Millennium Medical College (SPHMMC). Methodology: A hospital‑based cross‑sectional study was conducted among 65 eyes of 65 patients diagnosed with primary pterygium. Consecutive sampling was applied. Pre‑ and postoperative corneal astigmatisms were measured using an automated autorefractokeratometer, while visual acuity was assessed with a Snellen’s E chart and converted to logMAR. Data were collected via structured questionnaires and ocular examinations, then analyzed using SPSS version 26. Paired t‑tests compared pre‑ and postoperative corneal astigmatism mean, and multiple linear regressions identified associated risk factors. Statistical significance was set at p < 0.05. Results: Of the 65 patients, 61.5% were females, with a mean age of 37.8 years. Most resided in urban areas (72.3%), and merchants formed the largest occupational group (26.2%). Nasal pterygia were the most dominant (90.8%), and grade II lesions were most frequent (40%). Outdoor activity (73.8%) and sun exposure (66.2%) were common. Mean corneal astigmatism decreased significantly from 0.83 D preoperatively to 0.59 D at 1 month and 0.27 D at 3 months (p -0.000). UCVA improved from 0.21 logs MAR preoperatively to 0.14 at 1 month and 0.12 at 3 months (p -0.000). Conclusion: Pterygium excision with conjunctival autograft significantly reduces corneal astigmatism and improves visual acuity, supporting its role in restoring ocular function. Preventive strategies such as UV protection and early surgical intervention are essential, particularly for high‑risk groups. This study provides baseline evidence for Addis Ababa and contributes to improved clinical management and preventive measures against pterygium‑related visual impairment. Keywords: Corneal astigmatism, Pterygium, Conjunctival autograft.