Risk Factors for Recurrence After Pterygium Surgery: An Image Analysis Study

Purpose: To determine the risk factors related to recurrence of pterygium using automated image analysis.

Methods: This study included 149 eyes of 149 patients who underwent pterygium excision and limbal-conjunctival autograft. Demographic variables including age and sex were collected. Image analysis was performed using anterior segment photographs taken preoperatively to measure relative length (horizontal length of pterygium invading cornea/horizontal corneal diameter), relative width (width of pterygium invading cornea/vertical corneal diameter), relative area (RA; area of pterygium invading cornea/total corneal area), and vascularity index (VI; degree of vascularity). In all patients, recurrence of pterygium was determined at 1 year after surgery. Association between these factors and recurrence rate was evaluated with univariate and multivariate analyses.

Results: Recurrence at 1 year was reported in 18.8% (28/149) of the patients. Univariate analysis showed that relative length (P = 0.001), relative width (P = 0.031), relative area (P = 0.009), and VI (P < 0.001) were significantly associated with increased risk of recurrence, whereas age and sex had no significant association with recurrence. In multivariate analysis, only VI (P < 0.001) had significant correlation with recurrence. Patients with VI ≥30 had significantly higher recurrence rate than those with VI <30 (33.3% vs. 8.1%, P < 0.001).

Conclusions: Increased vascularity was associated with a higher risk of recurrence. Quantification of vascularity using automated image analysis might be useful in predicting the risk of recurrence.