Case Report: Successful control of ocular surface squamous neoplasia complicated by Alternaria alternata infection

Background Ocular surface squamous neoplasia (OSSN) is relatively common, but the cases complicated by fungal infection are quite rare. This study reviewed a rare case of OSSN complicated by Alternaria alternata infection. Case presentation A 59-year-old male patient presented with a one-month history of foreign body sensation and photophobia in the left eye. Diagnostic and evaluative procedures, including a series of pathogenic microorganism staining microscopy and culture, in vivo confocal microscopy, anterior segment optical coherence tomography, ultrasound biomicroscopy, and histopathological examination, were performed to assess the condition of the cornea, conjunctiva, and sclera. The patient received topical and systemic medication to control infection. Subsequently, he underwent surgical intervention for the left eye consisting of excision of the corneal and conjunctival lesions, cryotherapy, corneoscleral collagen cross-linking, and conjunctival autograft transplantation. Fungal culture of the conjunctival lesion tissue confirmed that the pathogen was Alternaria alternata (AA). Histopathological examination revealed ocular surface squamous neoplasia. The diseases were successfully controlled. Conclusion To our knowledge, this is the first case report of OSSN with Alternaria alternata infection. Microbiological culture remains the gold standard for diagnosing ocular infectious diseases. For this patient, the combined treatment achieved favorable local clinical control. This highlights the importance of combining multiple treatment methods when dealing with such cases.