Comparison Of Culture-Negative Vs Culture-Positive Fungal Keratitis: Clinical Features And Treatment Outcomes

To compare the clinical features and treatment outcomes between culture-negative (CN) and culture-positive (CP) fungal keratitis.

L V Prasad Eye Institute, Bhubaneswar

Clinical and microbiology data of patients diagnosed with fungal keratitis at a Tertiary Eye Care Centre in eastern India between January 2021 and December 2022 were retrospectively reviewed. Collected data included demographic details (age, gender, profession), ocular and systemic predisposing factors, history of ocular trauma, clinical presentation, smear and culture reports, management modalities and treatment outcomes.

Age, gender,  and duration of symptoms were comparable between CP and CN cases (P= 0.1082, 0.4411,0.7920, respectively). The absence of prior antimicrobial therapy was more common in the CP group (P=0.0004). CP cases presented with a poorer visual acuity (P<0.0001) and a larger infiltrate area (P<0.0001). CN cases had a better outcome with medical management (P=0.0028) a). In contrast, CP cases required greater number of surgical interventions (P=0.0081), of which a significantly higher proportion were ‘major’ surgical interventions, including therapeutic penetrating keratoplasty, vitreoretinal surgery and evisceration (P=0.0125). CP cases had higher rates of treatment failure (P=0.0442) and worse visual acuity outcomes (P=0.2831).

CP fungal keratitis is associated with worse presenting visual acuity, larger infiltrate, and poorer treatment outcomes compared to CN fungal keratitis. Culture positivity in fungal keratitis can therefore serve as a prognostic indicator for disease severity and may necessitate more aggressive medical management or earlier surgical intervention.