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.

引言：
光化性角化病（Actinic keratosis, AK）是一类主要与慢性紫外线暴露相关的癌前上皮病变。该病虽常累及日光暴露部位的皮肤，但在眼表的发病较为罕见。临床上，其表现可与眼表鳞状上皮肿瘤（ocular surface squamous neoplasia, OSSN）相似，因此需通过组织病理学检查以实现精准诊断与合理治疗。

病例报告：
患者为78岁男性，乙型肝炎表面抗原（hepatitis B surface antigen, HBsAg）阳性，因右眼视力进行性下降6个月、右眼可见肿物2个月前来就诊。右眼最佳矫正视力为6/12p，左眼为6/9。右眼裂隙灯检查可见角膜表面有一处4×1 mm的角化性病变，周围伴色素沉着。双眼均存在白内障。双眼眼底检查未见明显异常。临床初步考虑为眼表鳞状上皮肿瘤。遂切除病变组织并送检组织病理学分析，结果证实符合光化性角化病的病理特征。术后患者予以局部使用0.02%丝裂霉素C与1%醋酸泼尼松龙滴眼液治疗。随访期间未观察到复发。

结论：
眼表光化性角化病是一种罕见的潜在癌前病变，易与眼表鳞状上皮肿瘤相混淆。临床怀疑结合组织病理学检查是确诊的关键。手术切除联合局部化疗可实现有效治疗，并降低复发或恶性转化的风险。