Understanding Pterygium Surgery Outcomes: Revisiting Definitions of Recurrence and Postoperative Complications

BACKGROUND: Pterygium surgery results in various postoperative outcomes, but inconsistency in standard benchmark reporting for recurrence and postoperative complications hinders meaningful comparisons within the literature. PURPOSE: This structured narrative review aims to synthesize the existing literature on pterygium surgery outcomes, focusing on how recurrence and postoperative complications have been defined and reported. METHODS: A structured literature search of PubMed was performed to identify studies reporting definitions of pterygium recurrence and postoperative complications through June 2025. Studies were reviewed and categorized narratively according to recurring patterns in outcome definitions and reporting practices. Eligible studies included case series, clinical trials, and randomized controlled trials that reported postoperative recurrence or complications. Exclusion criteria included case reports (≤3 cases), non-English publications, inaccessible full texts, reviews, and unrelated topics. Recurrence definitions were categorized into four groups according to descriptive patterns across studies, while postoperative complications were thematically classified into seven major categories. Findings were synthesized narratively. Due to heterogeneity in definitions, a quantitative meta-analysis was not feasible. RESULTS: Out of the 1,264 articles screened, 527 met the inclusion criteria. Among these, 330 studies provided a clear definition of recurrence, while the remaining studies did not specify criteria. The 330 studies were categorized into four main groups for recurrent definition. Category A, the most commonly reported definition, was described as fibrovascular regrowth extending beyond the limbus onto the cornea and included 169 studies. In addition, 83 studies reported the same definition but specified a minimum corneal extension of 0.5-2 mm. Category B included 49 studies that used the Prabhasawat Tseng four-stage grading scale, which classifies recurrence based on the extent of fibrovascular tissue from the limbus onto the cornea. Category C consisted of 12 studies that distinguished between conjunctival and corneal recurrence, and Category D included 17 studies that employed author definitions.Additionally, postoperative complications were classified into seven major groups based on the clinical characteristics of graft-related issues, toxic effects, inflammation, infection, healing abnormalities, drug-induced, and other less frequently reported issues. Each category was further subdivided into specific clinical complication entities. CONCLUSION: Substantial variation exists in the literature on how recurrence and post-operative complications are defined following pterygium surgery. Establishing standardized classification systems is necessary and will enhance consistency in outcome reporting, improve clinical decision-making, and facilitate future meta-analyses and research goals.