A study on the association of ocular surface squamous neoplasia with pterygium

Background & Objectives: Pterygium is a fibrovascular degeneration of the conjunctiva. Ocular surface squamous neoplasia encompasses a wide spectrum of dysplastic changes including corneal and conjunctival intraepithelial neoplasia and squamous cell carcinoma. They both share common risk factors and can coexist concomitantly. This study aims to determine the association between OSSN and pterygium which will help to improve the management of pterygia cases with or without OSSN. Methods: This interventional prospective study has evaluated histopathological changes of excised pterygia of 51 patients (52 eyes) over a period of 14 months attending the outpatient department of Vydehi Institute of Medical Sciences and Research Centre, Bangalore. Results: The prevalence of OSSN coexistent with pterygium was found to be 1.92% and that of dysplasia was 9.61%. Also, these patients were found to have risk factors for malignancy like old age, smoking, recurrent pterygium, actinic keratosis. Interpretation and Conclusion: All cases of pterygium, especially those with risk factors need histopathological examination after surgical excision without fail. These pterygia need to be screened for dysplasia, metaplasia, anaplasia, ocular surface squamous neoplasia and to be managed accordingly. Chemotherapy with MMC, 5 FU if dysplastic cells are present. Immunotherapy with Interferon alpha 2b, excision with no touch technique and 4-5mm free margins excision around lesion and alcohol epitheliectomy and application of cryotherapy to surgical margins for OSSN is ideal treatment of cases with risk factor.