Turning the tide on myopia

First it begins with the blackboard, then the teacher, then a friend at a neighbouring desk.

The subtle but steady course of myopia is eroding the eyesight of millions of children globally, with familiar objects and faces fading away on a blurry tide.

A $1.9m (£1.5m) funding grant from the National Eye Institute will go towards unravelling the mystery of why growing numbers of patients are being stranded on diminishing islands of visual acuity.

Dr Earl Smith, dean of the University of Houston College of Optometry, told OT that myopia was a serious public health concern.

“It’s prevalence and severity is increasing. In East Asia myopia is the first to third most frequent cause of permanent blindness, in Caucasian populations it’s between the second and fifth most common cause,” he emphasised.

“Myopia is central to our profession. I view it as our responsibility to the world to try and reduce the effect that myopia has on society,” Dr Smith added.

There are three elements to the research that Dr Smith and his team will undertake as a result of the funding boost.

One project will investigate light levels and their impact on the risk of developing myopia, while another strand will focus on spectral composition. A third element of the research will examine the effects of a new pharmaceutical agent that has shown promise in reducing myopia.

Dr Smith explained that the same mechanism that gave most children normal vision at the age of five or six, was probably responsible for myopia.

“Understanding those mechanisms and why our behaviour and environment is promoting myopia at a higher rate than in the past is, I think, a fascinating question,” he highlighted.

Some factors were more clear-cut than others, Mr Smith noted. It was generally accepted that time spent outdoors was protective against myopia, but determining the cause of myopia was more difficult.

“There are a lot of reasons why that literature is murky. It probably has to do with the integration properties of these mechanisms. It makes it much more complex to understand what causes myopia, versus, in certain circumstances, what prevents it,” Dr Smith outlined.

Near work has been implicated in the development of myopia for a long time, but the data was not robust, he highlighted.

“It’s clearly significant but the strength of the association is not nearly as high as the protective effects that we see with outdoor time,” Dr Smith elaborated.

Dr Smith believes that the onset and intensity of education is a factor in the increasing prevalence of myopia, combined with a lack of outdoor time.

“If you look at East Asia, it’s not surprising that the epidemic of myopia has essentially run its course. They start formal education very, very early. Children go to school, they go to after school and then they do homework. It’s very intense – it dominates their behaviour and stops them from doing things like going outside,” Dr Smith highlighted.

The pharmaceutical agent that Dr Smith’s team is investigating through its research is a metabolite of caffeine, which does not have the psychoactive effects of caffeine found in coffee and energy drinks.

Dr Smith emphasised that the preliminary data on the drug was very strong.

“We are quite excited about it – it seems to be a very safe agent and it is a common dietary component,” he concluded.