Incidental ocular surface squamous neoplasia in pterygia: a systematic review and meta-analysis

Clinical Snapshot

Key Findings

• P Value: Not reported for primary outcome

• Effect Size: 1.32% prevalence

• Primary Outcome: Pooled prevalence of incidental OSSN in clinically diagnosed pterygia

• Nnt Or Sensitivity: Regional variation: Europe 0.29%, Asia 0.76%, North America 1.03%, Oceania 8.57%, South America 14.97%

• Confidence Interval: 95% CI 0.41% to 4.21%

Clinical Application

Routine histopathological examination of pterygium specimens is standard practice and feasible in Australian healthcare settings Highly relevant given Australia's high UV exposure and Oceania regional prevalence of 8.57%. Supports current Australian practice of routine histopathology for pterygium specimens. No specific PBS or TGA implications, but reinforces RANZCO guidelines for comprehensive pterygium management Patients with clinically diagnosed pterygia, particularly in high UV exposure regions like Australia

Abstract

AIMS: Differentiating pterygium from ocular surface squamous neoplasia (OSSN) is important for guiding management. This meta-analysis evaluates the prevalence and risk factors for incidental OSSN in clinically diagnosed pterygia. METHODS: Ovid Embase, MEDLINE, Cochrane Library and Web of Science were systematically searched from January 2000 to February 2025. Included studies analysed ≥100 clinically diagnosed pterygia via histopathology. Random-effects meta-analysis assessed the prevalence of incidental OSSN among pterygia. Risk factors were evaluated using the Mantel-Haenszel and inverse variance methods, and meta-regression analysed the influence of publication year, geographic proximity to the equator, and country-level ultraviolet (UV) radiation exposure. RESULTS: 12 studies, comprising 8688 specimens, identified 202 cases of incidental OSSN (pooled prevalence=1.32%, 95% CI 0.41% to 4.21%, I2=95.3%). Meta-regression revealed that lower OSSN prevalence was associated with greater distance from the equator (OR 0.49, 95% CI 0.28 to 0.83, p<0.01), while higher prevalence was associated with greater UV exposure (OR 2.20, 95% CI 1.17 to 4.14, p=0.01). Publication year had no effect (p=0.98). Age (p=0.18), sex (p=0.45) and lesion location (p=0.60-0.82) did not differ between incidental OSSN cases and benign pterygia. Incidental OSSN prevalence also did not differ between primary and recurrent pterygia (p=0.23). Regional analyses revealed variation in prevalence: Europe (0.29%), Asia (0.76%), North America (1.03%), Oceania (8.57%) and South America (14.97%). CONCLUSIONS: This meta-analysis, based on low- to very low-certainty evidence, identified a 1.32% pooled prevalence of incidental OSSN in clinically diagnosed pterygia, highlighting the potential influence of UV exposure and equatorial proximity. The overlap in demographic and lesion characteristics between benign pterygia and OSSN underscores diagnostic challenges.

References

1. 1.Mihalache, A., Huang, R. S., Balas, M., Bert, B., Godiwalla, R. Y., Hsu, H., Popovic, M., & Chan, C. C. (2026). Incidental ocular surface squamous neoplasia in pterygia: a systematic review and meta-analysis. British Journal of Ophthalmology. https://doi.org/10.1136/bjo-2025-328299