UTILITY OF AS-OCT IN PTERYGIUM SURGERY: CAN AS-OCT IDENTIFY PREDICTIVE FACTORS OF RECURRENCE?

The main objective of the study is to determine the anatomical characteristics both preoperatively and postoperatively by anterior segment optical coherence tomography (AS-OCT) that correlate with a higher rate of pterygium recurrence after surgery with exeresis and conjunctival autograft with biological glue.

50 patients which were listed for primary pterygium surgery at an Ophthalmology Tertiary Centre were treated with standard pterygium excision and conjunctival autograft with tissue glue and followed up during one year.

10 anatomical variables of the pterigyum or the graft were measured with AS-OCT (Casia 2; Tomey Corp., Nagoya, Japan) in 6 control visits in all patients before and after surgery. Finally, statistical analysis was performed using SPSS software, including a descriptive analysis and an inferential analysis studying prognostic factors of recurrence and their predictive capacity.

Among the 50 patients who underwent surgery, recurrence was detected in 8 cases (rate 16%; 95%CI: 5.8-26.2%). Most cases (n=6) were detected 3 months after surgery. The pattern of recurrences was atrophic in two thirds of the cases. Pre-operative total conjunctival thickness at 3mm was significantly increased in patients who developed recurrence. One week after surgery, epithelial and stromal thickness at 1mm and total thickness at 3mm proved to be useful for predicting recurrence. Both models have significant discriminant capacity.

By imaging the graft with AS-OCT at 7 days after surgery, the risk of future recurrence can be predicted. This could help to establish a standardized follow-up protocol in patients who undergo pterygium surgery in centers with AS-OCT.