Acremonium keratitis: Risk factors, clinical characteristics, management, and outcome in 65 cases

Purpose: To study the risk factors, clinical presentation, management options, and outcomes in cases of culture?proven Acremonium keratitis. Methods: Medical and microbiology records of culture?proven Acremonium keratitis from Jan 2007 to Dec 2019 at a tertiary eye care center were reviewed. Details of clinical findings on each visit and operating notes were reviewed from the medical records. All cases were subjected to corneal scraping at the first visit for microbiological investigation consisting of direct smear examination and culture. Topical natamycin 5% was the mainstay of medical treatment. Surgical treatment was considered for nonresponding patients. Results: During the 13?year study period, 65 cases of culture?proven Acremonium keratitis were identified out of 1605 cases of fungal keratitis. Trauma was the most common predisposing factor in 32 cases (49.2%). The average area of the corneal stromal infiltrate was 24.8 mm2 at the initial presentation. Hypopyon at the time of presentation was evident in 28 (43.1%) cases. Staphylococcus spp. was the most common (n = 22, 33.8%) organism coexistent with Acremonium. Direct microscopy of corneal scraping was positive for fungal filaments in 57/65 (87.6%) cases. Medical management alone was given in 44 patients (67.6%). Age (>50 years) and treatment delay (>15 days) were found to be independent risk factors for the poor final visual outcome (VA <20/60). Conclusion: When treated early, Acremonium keratitis responds well to medical therapy with currently available topical antifungals. However, advanced and nonresponding cases require surgical intervention for resolution of the infection

Sensitivity and specificity of potassium hydroxide and calcofluor white stain to differentiate between fungal and Pythium filaments in corneal scrapings from patients of Pythium keratitis

Purpose: To assess the sensitivity of potassium hydroxide and calcofluor white (KOH+CFW) mount in the diagnosis of Pythium keratitis and concordance among microbiologists. Methods: Three microbiologists evaluated the microscopic images of KOH + CFW mounts of confirmed cases of Pythium and fungal keratitis seen between January 2019 and February 2021. The filaments were compared using specific differentiating features. The sensitivity and specificity of KOH + CFW in diagnosing Pythium infection were evaluated along with concordance among the microbiologists. Results: Sixty consecutive cases with confirmed growth of fungus or Pythium insidiosum (n = 29) were evaluated. The sensitivity of KOH + CFW in the correct identification of Pythium filaments ranged from 79.3% to 96.5% among three microbiologists. There was good interobserver (k = 0.76–0.90) and intraobserver (k = 0.70–0.97) agreements among three microbiologists. The differentiating findings (P < 0.0001) suggestive of Pythium filaments were the absence of septae in 23 (79.3%) and collapsed walls in 22 (75.9%) cases. Conclusion: KOH + CFW has good sensitivity and specificity in the diagnosis of Pythium keratitis with good interobserver and intraobserver concordance.

Efficacy of voriconazole and amphotericin B in corneal preservative media

Purpose: To evaluate the efficacy of voriconazole and amphotericin B in McCarey–Kaufman (MK) media. Methods: MK media vials were supplemented with either voriconazole at 1, 2, 20, 50, 100 ?g/mL or amphotericin B at 0.5, 1, 2, 10, 20 ?g/mL. The standard inoculum of the American Type Culture Collection (ATCC) strain of Candida albicans, Aspergillus flavus, and Fusarium keratinoplasticum was added to the set of vials. The efficacy outcomes were calculated as ‘viable fungal colony counts’ determined from the samples taken on Days 0 and 4. MK media containing fungal inoculum but without antifungal supplements were used as control. Results: In the voriconazole arm, on Day 4, a reduction in the colony count was observed for Candida albicans (1 ?g/mL, 36%; 100 ?g/mL, 100%), Aspergillus flavus (1 ?g/mL, 53.8%; 100 ?g/mL, 80.4%), and Fusarium keratinoplasticum (1 ?g/mL, 39.0%; 100 ?g/mL, 72.2%). Similarly, in the amphotericin B arm, on Day 4, a reduction in the colony count was observed for Candida albicans (0.5 ?g/mL; 99.9%; 20 ?g/mL, 100%), Aspergillus flavus (0.5 ?g/mL, 65.2%; 20 ?g/mL, 84.8%), and Fusarium keratinoplasticum (0.5 ?g/mL, 90.1%; 20 ?g/mL, 100%). Conclusion: Compared to voriconazole, the addition of amphotericin B significantly reduces fungal contamination in MK media.