Supplementary Material for: Corneal Actinic Keratosis in an Elderly Farmer: A Rare Case Report

Introduction:
Actinic keratosis (AK) is a premalignant epithelial lesion primarily associated with chronic ultraviolet exposure. While it commonly affects sun-exposed skin, its occurrence on the ocular surface is rare. Clinically, it may resemble ocular surface squamous neoplasia (OSSN), necessitating histopathological confirmation for accurate diagnosis and appropriate management.
Case Presentation:
A 78-year-old male, HBsAg positive, presented with progressive diminution of vision in the right eye for 6 months and a visible mass over the right eye for the past 2 months. Best-corrected visual acuity was 6/12p in the right eye and 6/9 in the left eye. Slit-lamp examination of the right eye revealed a 4×1 mm keratotic lesion with surrounding hyperpigmentation on the corneal surface. Both eyes were cataractous. Fundus evaluation was within normal limits in both eyes. A clinical diagnosis of ocular surface squamous neoplasia was considered. The lesion was excised and sent for histopathological analysis, which revealed features consistent with actinic keratosis. The patient was treated with topical mitomycin C 0.02% and topical prednisolone acetate 1% postoperatively. No recurrence was observed on follow-up.
Conclusion:
Ocular surface actinic keratosis is a rare and potentially premalignant lesion that may mimic OSSN. Clinical suspicion, combined with histopathological examination, is crucial for diagnosis. Surgical excision followed by topical chemotherapy offers effective management and reduces the risk of recurrence or malignant transformation.