Time to Keratometric Stability after Pterygium Excision Surgery in a Tertiary Hospital in the Philippines

Background. Pterygium is a common benign fibrovascular growth of the conjunctiva extending onto the cornea that induces corneal distortion and astigmatism as it progresses. Following excision, transient keratometric instability may occur, making the timing of refractive procedures dependent on the restoration of corneal stability.

Objectives. The study aimed to identify the time to achieve keratometric stability after pterygium excision surgery and associated factors.

Methods. This was an observational retrospective cohort study of patients who underwent pterygium excision within a period of 6 months. Data were abstracted from electronic medical records. The Kaplan-Meier method and log-rank test were used to analyze the time to keratometric stability. Cox proportional hazards regression analysis was used to identify the associated factors.

Results. A total of 58 eyes that underwent pterygium excision from January 2022 to December 2023 were included in the analysis. There was no statistically significant difference in terms of age, sex, laterality, polarity, and surgical technique. Ninety-one percent (n=53) demonstrated keratometric stability three months after pterygium excision. All eyes (100%) reached keratometric stability at the post-operative six-month period. The median time to reach keratometric stability was 4 weeks (1 month), and the maximum time is six months.

Conclusion. Higher-grade pterygia required longer to achieve postoperative keratometric stability, informing optimal timing of subsequent procedures. Biometry for cataract surgery is best performed ≥3 months after excision (≈6 months for Grade 3) to ensure accurate IOL calculation, with further studies needed to evaluate varied cases and long-term outcomes.