S1.5a Epidemiology of myotic keratitis in developing countries

Abstract

S1.5 Mycotic keratitis, September 21, 2022, 11:00 AM - 12:30 PM Mycotic keratitis (corneal infection due to a fungal etiology) is a well-recognized ophthalmological emergency warranting rapid initiation of specific antifungal therapy. However, the magnitude of the problem of mycotic keratitis in the community, especially in the Indian subcontinent and the developing world, is, perhaps, less apparent. A minimal annual incidence estimate of 1051, 787 cases (23.6/100 000 population [popln]) globally has recently been reported, with the highest rates being in Asia (33.9/100 000 popln, an absolute number of 939 895) and Africa (13.5/100 000; 75 196); if all culture-negative cases are assumed to be fungal, especially where the incidence of mycotic keratitis is known to be high, then the annual incidence would be about 1480 916 cases. A fungal etiology has been found to account for a very high proportion (> 45%) of microbial keratitis cases in countries in the Indian subcontinent. Countries where a fungal etiology accounts for >25% of microbial keratitis mostly tend to abut the equator. Interestingly, the proportion of microbial keratitis patients with a proven fungal etiology shows a significant negative correlation with the gross domestic product per capita. Although it is clear that the most common fungal species are Fusarium, Aspergillus, and Candida species, marked regional variations in fungal etiology have been noted. It is important to realize that sensitivity of the culture of ocular fungal pathogens can vary, depending on the pathogen, as well as the competence of the testing laboratory. For some countries, multiple reports over time have been noted, with there being some evidence of an increasing trend in the proportion of all microbial keratitis cases being diagnosed as mycotic keratitis. Even in a single geographical location, cases of mycotic keratitis may be higher than the yearly average at certain times of the year, such as during the harvest or windy seasons, or when there is increased relative humidity. A disturbing statistic to note is that, in 8%-11% of patients with mycotic keratitis, the affected eye needs to be removed, representing an irreversible annual loss of 84 143-115 697 eyes. It is recognized that many people suffering from mycotic keratitis in rural distant communities never present to health care workers due to financial and other constraints. Hence, the actual number of people afflicted by mycotic keratitis, man-days lost due to the disease and during therapy, and reduced quality of life due to persistent disability (corneal scarring) in the Indian subcontinent and developing countries requires further study.