Shweta Agarwal1, Bhaskar Srinivasan1, Narayanan Janakiraman2, Lily K Therese3, KrishnaKumar S4, Nilay Patel1, Thenmozhi V5, Geetha Iyer1. 1. CJ Shah Cornea Services, Dr G Sitalakshmi Memorial Clinic for Ocular Surface Disorders, Medical Research Foundation, Sankara Nethralaya, Chennai, India. 2. Department of Nano Biotechnology, Vision Research Foundation, Sankara Nethralaya, Chennai, India. 3. L&T Microbiology Research Centre, Vision Research Foundation, Sankara Nethralaya, Chennai, India. 4. L&T Ophthalmic Pathology Department, Vision Research Foundation, Sankara Nethralaya, Chennai, India; and. 5. Elite School of Optometry, Birla Institute of Technology and Science, Chennai, India.
Abstract
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 study the efficacy and safety profile of topical absolute ethanol in the treatment of Pythiuminsidiosum 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.