Microbiological Profile of Culture-Positive Fungal Keratitis.

PURPOSE: To examine the microbiological profile of cases of culture-positive fungal keratitis presenting to a tertiary eye care center in eastern India. METHODS: Microbiology records of all culture-positive microbial keratitis patients presenting to L V Prasad Eye Institute, Bhubaneswar, between January 2020 and December 2021, were retrospectively reviewed. Collected data included smear results of culture-positive fungal or mixed infections, the species isolated, and the time taken for organisms to grow in each media. RESULTS: Fungal keratitis formed 36% of all culture-positive microbial keratitis, whereas mixed infections (fungi and other organisms) formed 8.5%. The most common fungal species isolated was Fusarium spp. (25.8%). The most common bacteria involved in mixed infection with fungi was Staphylococcus spp. (54.8%). The positivity of potassium hydroxide+calcofluor white stain in detecting fungal filaments was 89.0% and that of Gram stain was 76.1%. Culture-positive cases of fungal keratitis showed most frequent growth on potato-dextrose agar (77.6%). A similar pattern was observed in culture-positive mixed infections (Sabouraud dextrose agar [SDA]: 84%). Most frequent growth of bacteria in mixed infections was seen in thioglycolate broth (54.7%). The shortest time to achieve significant fungal growth was observed in blood agar (BA) and chocolate agar (CA) (2.2/2.3 days, and 1.8/2 days for fungal keratitis and mixed infections, respectively). Filamentous hyaline fungi took the shortest time to achieve significant growth (2.8 days), whereas yeast forms took the longest (5 days). CONCLUSION: This study highlights the importance of combined use of both solid and liquid culture media, especially potato dextrose agar (PDA)/SDA and CA, to arrive at a definitive diagnosis of fungal keratitis and possible bacterial co-infection, which forms a significant proportion of cases with fungal keratitis. In resource-poor laboratories, two culture media, either SDA or PDA, along with BA, may be plated to detect mixed infections. Examination of stained smears of corneal samples provides an inexpensive method of rapid diagnosis of fungal keratitis when culture media is not available.

Keratic Precipitates: An Overlooked Sign of Microsporidial Stromal Keratitis?

PURPOSE: To elucidate a distinctive clinical feature in cases of microsporidial stromal keratitis (MSK). METHOD: A retrospective observational study of cases with a histopathological and/or microbiological diagnosis of MSK on corneal biopsy or host corneal button between 2016 and 2022 was conducted. RESULTS: Eighteen cases with a confirmed histopathological and/or microbiological diagnosis of MSK were detected. Careful review of slit-lamp photographs revealed the presence of pigmented keratic precipitates (KPs) beyond the area of stromal keratitis in five out of eighteen cases (27.7%). CONCLUSION: The presence of pigmented KPs beyond the area of lesion can alert the clinician to keep microsporidia as a differential cause for stromal keratitis. Management can be tailored accordingly for a better outcome.

Use of Ethylenediaminetetraacetic Acid in Chronic Calcium-Based Chemical Injury.

PURPOSE: This study presents the successful management of a patient with chronic chemical-based injury using ethylenediaminetetraacetic acid (EDTA) chelation. METHODS: This is a case report of a 59-year-old man who presented to us 2 months after a bilateral, accidental, ocular injury with lime particles at his workplace. RESULTS: The patient was initially managed with extensive debridement and amniotic membrane grafting for both eyes. At 4-month follow-up, the left eye appeared to have extensive calcium-based plaques. 0.02N EDTA chelation was performed for his left eye. Postchelation, the visual acuity improved to 20/800. At 1-week follow-up, a repeat EDTA chelation was performed. The corneal clarity improved further, and the patient recovered a visual acuity of 20/200. CONCLUSIONS: EDTA chelation in the setting of calcium deposition in the chronic phase of chemical injuries can be reasonably effective.