Eyeworld Daily News

EW SHOW DAILY 36 ASCRS Symposia Tuesday, April 21, 2015 by Lauren Lipuma EyeWorld Staff Writer treatment shown to have a signifi- cant effect. Donald T.H. Tan, MD, Singapore, shared results from the studies conducted at the Singapore Eye Research Institute (SERI) on the use of atropine, an anti-muscarinic agent, for myopic prevention in the Richard L. Lindstrom Lecture, "The Use of Atropine for Myopia Preven- tion." Atropine 1% eye drops have been available for more than 40 years and have been used in East Asian countries to slow the progres- sion of myopia since the 1990s, Dr. Tan said. Atropine's mechanism of action is unclear, but studies have shown that it does not work by blocking accommodation. Dr. Tan and colleagues per- formed 2 randomized controlled trials at SERI to determine atropine's effectiveness in halting distance vi- sual acuity decline and axial elonga- tion. The first study, named ATOM1, compared 1% atropine to placebo drops in 400 children studied over 3 years. The second study, ATOM2, compared the effects of lower doses of atropine—0.5%, 0.1%, and 0.01%—to placebo drops in 400 children over a period of 5 years. The major conclusions from these studies are that atropine drops slow myopia progression and axial elongation in children in a dose-re- lated manner, but a rebound effect occurs with higher doses—axial length and myopia increase again after the drops are stopped. Atropine 0.01% has the best therapeutic in- dex, slowing progression of myopia by as much as 50–60%. There are many more questions to be answered, but Dr. Tan believes that this is a huge step forward. "It's fascinating that now we're reaching a time when a lot of these studies are showing promise," he concluded. EW Editors' note: Dr. Tan has financial interests with Carl Zeiss Meditec (Jena, Germany), Eye-Lens Pte Ltd (Singapore), Network Medical Products (Ripon, England), and Santen Pharmaceutical (Osaka, Japan). Drs. Khandelwal and Coroneo have no financial interests related to this article. "If this was a stagnant disease, it would be manageable, but the fact that we see increasing prevalence at a younger age is probably of the most concern," said Sumitra Khandelwal, MD, Houston. The protective effect of out- door activity on myopia has been shown in several prospective studies and randomized clinical trials. The exact mechanism for this effect is unknown, but it could be due to looking at far distances, ocular sun exposure, vitamin D, or other fac- tors, Dr. Coroneo said. In several studies, conjunctival autofluorescence staining has been used as a measure of ocular sun exposure and found to be associated with a higher prevalence of myopia. In one study, myopes were found to have lower vitamin D levels, but fur- ther studies are needed to determine if vitamin D itself has a protective effect or if it is a proxy for some oth- er biological mediator, he said. Can progression be stopped? Spectacles, multifocal contact lenses, overnight corneal reshaping, and anti-muscarinic eye drops have all been studied as methods to halt myopic progression, but anti-mus- carinic eye drops are the only myopia progression and highlighted the treatments that show the most promise. Understanding the disease The mechanisms behind myopia progression are not clearly un- derstood, but it is most likely due to a combination of genetic and environmental factors. The steep rise in prevalence of myopia over the past 50 years suggests than the environment plays a key role, and reduced outdoor activity could be the culprit, said Minas T. Coroneo, MD, Sydney. T he prevalence of myopia is increasing so rapidly that it's becoming an epidemic in the Asian world, and the western world is not far behind. Physicians have made many attempts over the years to slow the progression of myopia, but whether these methods are effective remains an unanswered question. In Monday afternoon's "My- opia: Can Progression be Halted?" session sponsored by the Contact Lens Association of Ophthalmolo- gists (CLAO), leading experts dis- cussed the current understanding of Can progression of myopia be stopped? Deborah S. Jacobs, MD, and Deepinder K. Dhaliwal, MD, present Dr. Tan with the 2015 Richard L. Lindstrom Award. " If this was a stagnant disease, it would be manageable, but the fact that we see increasing prevalence at a younger age is probably of the most concern. " –Sumitra Khandelwal, MD

• Cover