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Aim: To report a case of bilateral microsporidiosis with coexisting fungal infection in one eye., Method: Retrospective interventional case report., Results: A 61-year-old man with uncontrolled diabetes presented with clinical and microbiological features of non-resolving fungal keratitis in the right eye since 3 months and underwent therapeutic penetrating keratoplasty (TPK) for the same. Fungal filaments along with oval bodies suspicious of microconidia were noted on calcofluor stain. A week following TPK, the patient presented with features of viral keratouveitis in the left eye which on microbiology was confirmed as microsporidiosis. Retrospectively, the right eye microbiology slides were reassessed, which confirmed the coexistence of fungus with microsporidiosis by acid-fast stain and polymerase chain reaction., Conclusion: Structural resemblance of microconidia with microsporidial spores can be misleading, thus creating a need for awareness regarding the possible coexistence along with a need to suspect microsporidiosis in nonresponding clinically resembling viral keratitis.

Purpose: To present a case of necrotizing sclerokeratitis in a patient with multidrug-resistant tuberculosis and study the challenges in diagnosis and management of anterior tuberculous scleritis., Methods: Retrospective observational case report and review of anterior tuberculous scleritis., Results: A 28-year-old woman, previously diagnosed as presumed tubercular panuveitis, presented with necrotizing sclerokeratitis and progressed to develop panophthalmitis. Laboratory investigations revealed multidrug-resistant Mycobacterium tuberculosis as the etiological agent. We reviewed cases of anterior tuberculous scleritis published in the literature, with regards to clinical features, microbiological investigations, treatment, and outcomes. Treatment includes standard antitubercular therapy, with or without systemic corticosteroids. Poor response to treatment is seen either due to delayed diagnosis or drug resistance, and the significance of the same is highlighted in our case., Conclusion: Diagnosis of tuberculous scleritis is a challenge. Therapeutic failure must alert the clinician for drug resistance which is diagnosed early, can prevent the devastating outcomes.

Infectious keratitis is a medical emergency resulting in significant visual morbidity. Indiscriminate use of antimicrobials leading to the emergence of resistant or refractory microorganisms has further worsened the prognosis. Coexisting ocular surface diseases, delay in diagnosis due to inadequate microbiological sample, a slow-growing/virulent organism, or systemic immunosuppressive state all contribute to the refractory response of the ulcer. With improved understanding of these varied ocular and systemic factors contributing to the refractory nature of the microbes, role of biofilm formation and recent research on improving the bioavailability of drugs along with the development of alternative therapies have helped provide the required multidimensional approach to effectively diagnose and manage cases of refractory corneal ulcers and prevent corneal perforations or further dissemination of disease. In this review, we explore the current literature and future directions of the diagnosis and treatment of refractory keratitis., Competing Interests: None

Pythium insidiosum is an oomycete and is also called "parafungus" as it closely mimics fungal keratitis. The last decade saw an unprecedented surge in Pythium keratitis cases, especially from Asia and India, probably due to growing research on the microorganism and improved diagnostic and treatment modalities. The clinical features such as subepithelial infiltrate, cotton wool-like fluffy stromal infiltrate, satellite lesions, corneal perforation, endoexudates, and anterior chamber hypopyon closely resemble fungus. The classical clinical features of Pythium that distinguish it from other microorganisms are reticular dots, tentacular projections, peripheral furrowing, and early limbal spread, which require a high index of clinical suspicion. Pythium also exhibits morphological and microbiological resemblance to fungus on routine smearing, revealing perpendicular or obtuse septate or aseptate branching hyphae. Culture on blood agar or any other nutritional agar is the gold standard for diagnosis. It grows as cream-colored white colonies with zoospores formation, further confirmed using the leaf incarnation method. Due to limited laboratory diagnostic modalities and delayed growth on culture, there was a recent shift toward various molecular diagnostic modalities such as polymerase chain reaction, confocal microscopy, ELISA, and immunodiffusion. As corneal scraping (10% KOH, Gram) reveals fungal hyphae, antifungals are started before the culture results are available. Recent in vitro molecular studies have suggested antibacterials as the first-line drugs in the form of 0.2% linezolid and 1% azithromycin. Early therapeutic keratoplasty is warranted in nonresolving cases. This review aims to describe the epidemiology, clinical features, laboratory and molecular diagnosis, and treatment of Pythium insidiosum keratitis., Competing Interests: None

Purpose: To study the efficacy and safety profile of topical absolute ethanol in the treatment of Pythium insidiosum keratitis., Method: Microbiological, clinical, and histopathological assessments were performed to study the effects of absolute ethanol on P. insidiosum keratitis. In addition, infrared spectroscopy was performed to assess the corneal penetration of ethanol., Results: Microbiological tests revealed that ethanol inhibited the growth of P. insidiosum at concentrations even as low as 20% as compared to Candida albicans and Aspergillus flavus, where minimal growth was noted. However, at 40%, 60%, 80%, and 99.9% of ethanol, complete inhibition of growth was noted for all organisms. Histopathology of the absolute ethanol-treated cadaveric cornea showed the compaction of collagen and no stromal necrosis. Infrared spectroscopy revealed secondary structural changes in collagen in the ethanol-treated cadaveric corneas as compared to controls. Clinically, 1 case with a recurrence of P. insidiosum after therapeutic penetrating keratoplasty resolved with the topical application of absolute ethanol, and the other case, where corneal scraping had grown Pythium within 24 hours, failed to grow the organism from the corneal button which was treated with absolute alcohol preoperatively. After therapeutic penetrating keratoplasty, there was no recurrence, and the graft epithelized well., Conclusions: Ethanol can be considered an option for treating P. insidiosum keratitis; however, the exact dose and strength of ethanol which will be most effective needs further work.

Purpose: To report the clinical profile and role of perioperative adjunctive measures to reduce the risk of recurrence in Pythium insidiosum keratitis., Methods: Retrospective analysis of 10 eyes of 10 patients with P. insidiosum keratitis. Diagnosis was confirmed by PCR DNA sequencing., Results: 7out of 10 patients were from urban locales, and none had any obvious history of injury with vegetative matter and were being treated for fungal keratitis. 6 eyes presented with central full thickness infiltrates with subepithelial and superficial stromal infiltrates radiating in a reticular pattern. Corneal scraping in all eyes revealed sparsely septate fungal-like filaments on potassium hydroxide/Calcofluor. All eyes underwent the first therapeutic penetrating keratoplasty (TPK) based on worsening or non-responsiveness of clinical features to the antifungal regimen. Recurrence was noted in 7 out of 10 eyes of which 2 eyes underwent evisceration. Of the six eyes that underwent cryotherapy following confirmation of microbiological diagnosis of Pythium (along with primary TPK-1, with re-TPK-5), only one eye had a recurrence and had to be eviscerated. Of the two eyes that did not undergo cryotherapy during re-TPK, following microbiological diagnosis, one eye had a recurrence and had to be eviscerated. In two eyes with adjoining scleritis, the host bed was swabbed using absolute alcohol of which one eye was salvaged., Conclusion: This series highlights the need to be aware of this entity in the management of refractory fungal keratitis. It also brings to fore the adjunctive measures that could have a beneficial role in the management of pythium keratitis., Competing Interests: Competing interests: None declared., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Purpose: To analyze the influence of infiltrate size, depth, and organism on the outcome of microbial keratitis. Design: Retrospective comparative study. Methods: Medical records of patients with infective keratitis, who reported from January 2015 to December 2019 to a tertiary eye care center, were analyzed. Size and depth of ulcer at presentation were the factors used to group patients, and the influence on the outcome of the organism causing it was analyzed. Grouping was as follows: group A: ulcer size <6 mm/anterior to midstromal infiltrate, group B: ulcer < 6 mm/full-thickness infiltrate, group C: ulcer >6 mm/anterior to midstromal infiltrate, group D: ulcer > 6 mm/full-thickness infiltrate. Patients with viral keratitis or unidentified organism were excluded. Response to treatment and best-corrected visual acuity (BCVA) at the final follow-up were the outcome measures. Results: In the study, 1117/6276 patients were included, with 60.8% patients in group A. A significant improvement in visual acuity was noted in groups A/B compared to groups C/D. Group A had the best response to medical management, irrespective of the organism. Higher risk for surgery was noted in group C compared to group B, with group A as the reference. Overall resolution with medical treatment was noted in 70% miscellaneous keratitis, 64.8% bacterial keratitis, 64.3% mixed keratitis, 62.5% acanthamoeba keratitis, 52.6% fungal keratitis, and 12.1% Pythium keratitis. Bacteria and acanthamoeba responded better to medical management than fungal keratitis, whereas Pythium had the highest risk for surgery. Conclusion: An interplay between virulence of the organism along with depth and size of the infiltrate determines the outcome of microbial keratitis. [ABSTRACT FROM AUTHOR]

The document is a response to comments on a paper titled "Depth, size of infiltrate, and the microbe – The trio that prognosticates the outcome of infective keratitis." The authors acknowledge previous reports that mention larger ulcer size and deeper infiltrates, with some species like Aspergillus having poorer outcomes. The study aims to analyze whether infiltrates of similar size and depth caused by different microorganisms exhibit similar behavior, grouping patients based on ulcer size and infiltrate depth to compare outcomes. The conclusion suggests an interplay between the size of the infiltrate, depth of involvement, and the virulence of the organism in determining the outcome of microbial keratitis. [Extracted from the article]

Pythium insidiosum is an oomycete and is also called "parafungus" as it closely mimics fungal keratitis. The last decade saw an unprecedented surge in Pythium keratitis cases, especially from Asia and India, probably due to growing research on the microorganism and improved diagnostic and treatment modalities. The clinical features such as subepithelial infiltrate, cotton wool-like fluffy stromal infiltrate, satellite lesions, corneal perforation, endoexudates, and anterior chamber hypopyon closely resemble fungus. The classical clinical features of Pythium that distinguish it from other microorganisms are reticular dots, tentacular projections, peripheral furrowing, and early limbal spread, which require a high index of clinical suspicion. Pythium also exhibits morphological and microbiological resemblance to fungus on routine smearing, revealing perpendicular or obtuse septate or aseptate branching hyphae. Culture on blood agar or any other nutritional agar is the gold standard for diagnosis. It grows as cream-colored white colonies with zoospores formation, further confirmed using the leaf incarnation method. Due to limited laboratory diagnostic modalities and delayed growth on culture, there was a recent shift toward various molecular diagnostic modalities such as polymerase chain reaction, confocal microscopy, ELISA, and immunodiffusion. As corneal scraping (10% KOH, Gram) reveals fungal hyphae, antifungals are started before the culture results are available. Recent in vitro molecular studies have suggested antibacterials as the first-line drugs in the form of 0.2% linezolid and 1% azithromycin. Early therapeutic keratoplasty is warranted in nonresolving cases. This review aims to describe the epidemiology, clinical features, laboratory and molecular diagnosis, and treatment of Pythium insidiosum keratitis. [ABSTRACT FROM AUTHOR]