Vision-Threatening Ulcerative Infectious Keratitis in Diabetic Patients: A Retrospective Case Series

Purpose: This retrospective case series investigates the clinical manifestations, microbiological profiles, and therapeutic responses of ulcerative infectious keratitis in patients with diabetes mellitus (DM), aiming to highlight the challenges diabetes imposes on disease progression, treatment efficacy, and corneal healing.Materials and Methods: Three adult patients with confirmed DM presented between August 2022 and April 2023 with unilateral ulcerative infectious keratitis following ocular trauma. Data were collected from medical records, including systemic and ocular history, clinical findings, microbiological results, treatments, and follow-up outcomes. All patients underwent standardized ophthalmic and microbiological evaluations. Broad-spectrum empiric antimicrobial therapy was initiated and subsequently adjusted based on culture results. Concurrent glycemic optimization was maintained throughout the treatment course due to its impact on healing and infection control. Results: Two patients were diagnosed with fungal keratitis (Case 1: Fusarium solani, Case 2: Aspergillus spp.), and one with bacterial keratitis (Case 3: Staphylococcus aureus). Case 1, with poorly controlled type 2 DM, had the most aggressive disease course, requiring therapeutic penetrating keratoplasty (TPK) and resulting in poor visual outcome. Case 2 showed partial clinical improvement with prolonged antifungal therapy but residual stromal scarring. Case 3 demonstrated resolution of infection with targeted antibiotics; however, visual recovery was limited despite clinical stabilization.Conclusion: Ulcerative keratitis in diabetic patients presents a multifactorial clinical challenge. Managing such infections requires early diagnosis, prompt initiation of targeted antimicrobial therapy, and strict glycemic control. Addressing these factors collectively is essential for improving prognosis and preserving vision in this high-risk population.