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Seasonal Effects on Pterygium Surgery Outcome: Implications for the Role of Sunlight Exposure

Purpose: The aim of this study was to compare the results of pterygium surgery in patients when performed in the summer with the results of surgery performed in the winter. Methods: This retrospective study enrolled 55 eyes of 53 patients with primary pterygia who underwent a surgery between December 2011 and January 2012 (winter group, 32 eyes) or between June and July 2012 (summer group, 23 eyes). All the patients were followed up for at least 1 year. Pterygium recurrence, ocular discomfort, persistent conjunctival inflammation, and graft complications were evaluated postoperatively. Results: There was no significant difference between the groups in terms of age or gender. All the patients were farmers in rural areas. The overall pterygium recurrence rate was 14.5% (8 of 55 eyes). The recurrence rate in the summer group was significantly higher than in the winter group (26.1% vs. 6.2%, P = 0.048). Persistent conjunctival inflammation was also significantly higher in the summer group than in the winter group (30.4% vs. 6.2%, P = 0.022). Pterygium recurrence was significantly higher in eyes with persistent conjunctival inflammation than in eyes without inflammation (66.6% vs. 4.3%, P < 0.001). Mild and moderate ocular discomfort was significantly more frequent in the summer group than in the winter group (69.5% vs. 34.3%, P = 0.01). Conclusions: Pterygium recurrence rates were higher, and postsurgical discomfort was more common when pterygium surgery was performed in the summer compared with that in the winter, potentially because of the increased exposure to sunlight during the summer.