Researchers are beginning to address the increasing incidence of myopia
Currently, more than 1.6 billion people in the world are myopic, and this number is expected to increase. Although today’s conventional contact lenses and spectacles correct this refractive error, they do not slow the progression of the condition. Because myopia can progress rapidly in childhood and adolescence, some doctors feel that more proactive anti-myopia strategies should be began as early as possible.
The limitation of many current myopia correction methods has led to a great deal of research into new optical approaches that can cause the slowing myopia progression. One of the newest studies are the use of peripheral defocus lenses. A state of defocus on the peripheral rather than the central retina is thought to be an important mechanism in controlling the myopic progression. The goal is to impose the defocus on the periphery of the retina without compromising vision in the central retina.
Ortho-K has shown to be effective in cases of high myopia. However Ortho-K lenses are more complicated and intrusive than regular contact lenses. Another approach to myopia control is the use of a new type of contact lenses specifically designed to decrease peripheral focus. These new contact lenses are still under research but do suggest that by manipulating peripheral focus it can change refractive development and slow myopic progression. Another approach currently used to slow myopia is treatment with bifocal contact lenses. In many circumstances bifocal contact lenses can slow myopic progression by 40%. However it depends on the level of visual compromise those bifocal contact lenses produce in children.
Pharmaceutical agents such as atropine have been used to slow myopic progression. However follow-up data has shown that there is a rebound effect and the eyes can become more myopic when the medication is discontinued.
What does the future hold? I believe that future myopic interventions will address the problem using a variety of therapeutic approaches, from the use of environmental lifestyle changes to new optical appliances.
Despite the clear need, the industry has not been aggressive in developing anti-myopic lenses. However it is exciting to see what might come over the horizon in the near future.
Dr Joseph Bebber