Clinical analysis of fungal keratitis according to prior topical steroid use: A retrospective study

Abstract

Background: To compare the clinical characteristics and treatment outcomes of microbiologically-proven fungal keratitis between prior topical steroid users (PS) and no prior topical steroid users (NPS). Methods: Eighty-three cases with microbiologically-proven fungal keratitis between January 2000 and December 2016 were reviewed retrospectively. Diagnosis of fungal keratitis was made through potassium hydroxide smear, culture, PCR, or biopsy. Baseline epidemiology, predisposing factors and clinical characteristics, microbiological profiles, and treatment outcomes were compared between the PS and NPS groups. The treatment failure was defined as any case with complications or requiring surgery. The risk factors for treatment failure were evaluated on the bases of the total cohort and analyzed using multivariate logistic regression. Results: A total of 30 cases with PS group and 53 cases with NPS group were included. No significant differences were observed in mean age, sex, occupation, and baseline clinical characteristics between the two groups. Differences were observed between the PS and NPS groups in the cases of previous ocular surface disease (43.3% vs. 22.6%, p=0.048), identified fungal isolates (53.3% vs. 26.4%, p=0.014), and diagnosed by repeat microbiological tests (40.0% vs. 17.0%, p=0.020). Candida was the most common organism in both groups (6 cases, respectively), while the Aspergillus (4 cases) was found only in the PS group (p=0.015). Regarding treatment outcomes, the use of voriconazole (topical 10% vs. 0%, p=0.044; systemic 23.3% vs. 1.9%, p=0.003), surgical intervention (43.3% vs. 20.8%, p=0.029) and treatment failure (46.7% vs. 22.6%, p=0.023) were more common in the PS group than in the NPS group. The risk factors for treatment failure were hypopyon (odds 5.95, p=0.003), prior topical steroid use (odds 3.45, p=0.034), and non-vegetable corneal trauma (odds 4.46, p=0.037). Conclusions: The PS group was more associated with previous ocular surface disease, and no significant differences were observed in the baseline clinical characteristics between the two groups. Diagnosis was more difficult and treatment results were worse in the PS group in this study. Repeat microbiological tests can be helpful in diagnosing fungal infections especially in the prior topical steroid used group. Keywords: Fungal ocular infection, Steroids, Ulcerative keratitis.