How common is microbial keratitis in children wearing orthokeratology?

This study estimated the incidence of microbial keratitis (MK) in children wearing overnight orthokeratology lenses in a group practice in Russia. The study observed a rate of MK of approximately 5 cases per 10,000 patient years, which is lower than previous reports from clinical data gathered over a decade ago, and similar to that associated with daily-wear soft contact lenses. The previous reported rate of MK was around 14 per 10,000 patient years,¹ utilizing data gathered from a survey of almost 200 eye care practitioners in the United States, with the clinical care occurring between 2004 and 2006. In this new study, data was gathered from a single, large group of eye care practices, with OK fits occurring between 2010 and 2018 and outcomes surveyed from 2018. The improved safety profile in this recent study likely reflects the effect of gathering data from a single group of practices with standardized training, whereas the previous study obtained data from numerous different practices. It could also reflect a concerted effort to improve OK safety and compliance in the past decade or so. 

This should give both practitioners and parents confidence in considering overnight orthokeratology as a means of myopia control. The mean age of MK was 15.2±1.1 versus the mean age of fitting 12 years, indicating children are more likely to experience MK years after being fitted, rather than in the first few months. This highlights the importance of remaining vigilant in educating patients on good hygiene and lens care for the duration of their treatment period. The finding of a higher safety profile compared to previous reports could be due to the data being gathered from a single group of practices with standardized training and care protocols, and/or reflecting a concerted effort to improve OK safety and compliance in the past decade or so.