Ocular Surface Squamous Neoplasia With Coexistent Microbial Keratitis: Incidence, Risk Factors, Clinical Features, Microbiological Profile, and Treatment Outcome.

Purpose The purpose of this study was to evaluate the incidence, clinical features, microbiology, risk factors, and treatment outcomes in cases of ocular surface squamous neoplasia (OSSN) with coexisting microbial keratitis (MK). Methods This was a retrospective case-control study from a cohort of 939 cases with OSSN. Results Twenty eyes (2%) with OSSN and MK were included in the study group and 100 age-matched eyes with only OSSN as controls. Most common presentation was a combination of pain, redness, watering, and decreased vision (50%) over a median duration of 14 days. Mean corneal surface involvement by MK was 48% with corneal perforation in 6 cases (30%). Microbiology showed 10 culture positive cases for Gram-positive organisms (n = 5), fungus (n = 4), or mixed infection (n = 1). In the salvaged eyes, MK resolved in 9 eyes (90%) on medical treatment at a mean duration of 30 days and keratoplasty was performed in 1 eye. OSSN treatment included wide excisional biopsy (n = 9/18; 50%), extended enucleation (n = 7/18; 39%), and orbital exenteration in 1. Over a mean follow-up of 12 months, vision salvage was achieved in 7 of 18 (39%) and globe salvage in 10 of 18 (55%). Logistic regression analysis showed the following significant risk factors for MK in OSSN: male sex, human immunodeficiency virus seropositivity, increasing tumor diameter, limbal epicenter, temporal quadrant, noduloulcerative morphology, pigmentation, scleral invasion, keratin, and corneal component of the OSSN lesion. Conclusions Rarely, MK can coexist with OSSN leading to a poor treatment outcome. Male sex, human immunodeficiency virus seropositivity, large limbal pigmented OSSN lesion with keratin and corneal component, noduloulcerative morphology, and scleral invasion were risk factors for this association.