From the diagnosis of infectious keratitis to discriminating fungal subtypes; a deep learning-based study.

Infectious keratitis (IK) is a major cause of corneal opacity. IK can be caused by a variety of microorganisms. Typically, fungal ulcers carry the worst prognosis. Fungal cases can be subdivided into filamentous and yeasts, which shows fundamental differences. Delays in diagnosis or initiation of treatment increase the risk of ocular complications. Currently, the diagnosis of IK is mainly based on slit-lamp examination and corneal scrapings. Notably, these diagnostic methods have their drawbacks, including experience-dependency, tissue damage, and time consumption. Artificial intelligence (AI) is designed to mimic and enhance human decision-making. An increasing number of studies have utilized AI in the diagnosis of IK. In this paper, we propose to use AI to diagnose IK (model 1), differentiate between bacterial keratitis and fungal keratitis (model 2), and discriminate the filamentous type from the yeast type of fungal cases (model 3). Overall, 9329 slit-lamp photographs gathered from 977 patients were enrolled in the study. The models exhibited remarkable accuracy, with model 1 achieving 99.3%, model 2 at 84%, and model 3 reaching 77.5%. In conclusion, our study offers valuable support in the early identification of potential fungal and bacterial keratitis cases and helps enable timely management.

Fungal keratitis in Iran: Risk factors, clinical features, and mycological profile.

Introduction: This study was intended to investigate the clinical features and predisposing factors of fungal keratitis (FK), as well as molecular identification and antifungal susceptibility of causative agents in Tehran, Iran. Methods: This cross-sectional study was carried out from April 2019 to May 2021. All fungi isolates were identified using conventional methods and were confirmed by DNA-PCR-based molecular assays. Matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) was used to identify yeast species. Minimum inhibitory concentrations (MIC) of eight antifungal agents were assessed according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) microbroth dilution reference method. Results: Fungal etiology was confirmed in 86 (7.23%) of 1189 corneal ulcers. A significant predisposing factor for FK was ocular trauma caused by plant materials. Therapeutic penetrating keratoplasty (PKP) was required in 60.4% of cases. The predominant fungal species isolated was Fusarium spp. (39.5%) followed by Aspergillus spp. (32.5%) and Candida spp. (16.2%). Discussion: The MIC results indicate that amphotericin B may be appropriate for treating FK caused by Fusarium species. FK caused by Candida spp. can be treated with flucytosine, voriconazole, posaconazole, miconazole, and caspofungin. In developing countries such as Iran, corneal infection due to filamentous fungi is a common cause of corneal damage. In this region, fungal keratitis is observed primarily within the context of agricultural activity and subsequent ocular trauma. Fungal keratitis can be managed better with understanding the "local" etiologies and antifungal susceptibility patterns.

Fungal keratitis caused by Pseudallescheria boydii: clinical and mycological characteristics.

BACKGROUND: Pseudallescheria keratitis is rare but important type of fungal keratitis because of the inherently resistance of the organism to many existing antifungal agents. METHODS: Slit-lamp and confocal microscopy were used for clinical examinations. Fungal isolates were identified based on morphological characteristics and DNA sequence of the internal transcribed spacer region (ITS). In vitro antifungal susceptibility testing for fungal isolates was performed according to the Clinical and Laboratory Standards Institute (CLSI, M38-A2). RESULT: All patients had a history of ocular trauma. In clinical examination hypopion were seen in three patients. The main antifungal medications were topical voriconazole. After treatment the visual acuity of all patients improved in 2-3 weeks. CONCLUSION: All four patients of Pseudallescheria keratitis had similar clinical features. Accurate and rapid identification of species should be helpful in treating p. boydii keratitis.

Clinical and mycological characteristics of keratitis caused by Colletotrichum gloeosporioides: A case report and review of literature.

INTRODUCTION: Colletotrichum species are well-known plant pathogens, which have been increasingly reported as the cause of keratitis or subcutaneous lesions in humans. In this study we reported a rare case of fungal keratitis from Iran and reviewed the literature. CASE PRESENTATION: A 69-year-old man whose right eye was injured by herbal material was examined by slit-lamp biomicroscopy and mycology investigation of corneal scrapings was done. The grown filamentous fungal was identified as Colletotrichum gloeosporioides based on morphological characteristics and DNA sequence of the internal transcribed spacer region. The isolated strain was sensitive to amphotericin B, caspofungin, anidolafungin, micafungin, voriconazole, and relatively resistant to fluconazole, and itraconazole. Patient was successfully treated with voriconazole. CONCLUSIONS: This report highlights that the early and accurate identification and therapy can helpful to management keratitis caused by C. gloeosporioides.