Disclosure: Lindstrom says it has financial disclosures for Bausch + Lomb, Eyenovia, Harrow Health, Imprimis, Johnson & Johnson Vision, Minnesota Eye Consultants/Unifeye Vision Partners, Sydnexis, Visionary Ventures and Zeiss.
In 1980, while helping the late George O. Waring III prepare the grant application for the soon to begin prospective review of the radial keratotomy study, I reviewed the world literature on the incidence and prevalence of myopia.
At that time in the United States, approximately 25% of the population was myopic, 25% was hyperopic, and 50% was emmetropic within ±0.5 D of plano, while 30% had astigmatism of 1 D or more. I was amazed to learn that in some Asian countries up to 50% of the population was myopic. Today, 4 decades later, the prevalence of myopia has increased from 25% to nearly 45% in the US, and in some Asian countries myopia is approaching 90%.
Richard L Lindstrom
In the United States today there are approximately 30 million children with some degree of progressive myopia, and an additional 1 million join each year. While there are multiple theories as to the cause and this extraordinary increase in myopia is likely multifactorial, most experts believe that a major factor is the increasing near demands placed on children during their developmental years. In today’s digital world, many of our youngsters spend 12 or more hours a day concentrated near printed material, a mobile phone, a tablet or a computer.
One might ask, does progressive myopia require treatment? After all, it is just an ametropia that can be corrected with glasses, contact lenses or even surgery. There is evidence that just as with glaucoma, where every millimeter of increased intraocular pressure counts, in myopia every one diopter progression is important and increases the risk of vision-threatening comorbidities.
The most common comorbidities are cataract, glaucoma, retinal detachment and the most feared myopic maculopathy. Even with a slight myopia of -2 D, the risk of cataracts is increased twice, for glaucoma four times, for retinal detachment three times and for myopic maculopathy twice. With moderate myopia between -2 D to -6 D, the risk of cataracts increases threefold, glaucoma fourfold, retinal detachment ninefold and myopic maculopathy tenfold. From -6 D to -9 D the risk of cataracts increases 5-fold, glaucoma 14-fold, retinal detachment 22-fold and myopic maculopathy 41-fold. Above -9 D, the risk of retinal detachment is an alarming 44 times greater and the risk of myopic maculopathy 348 times greater than in a normal or hyperopic patient. Every dioptre counts in progressive myopia.
The basis of the therapeutic pyramid in treating progressive myopia is behavior modification. One to two hours of outdoor play a day is therapeutic, perhaps by switching from near to far vision and perhaps by increasing exposure to more violet and blue light. In addition, it is recommended to follow the 20-20-20 rule, which involves staring at an object 20 or more feet away for at least 20 seconds after every 20 minutes of close-up prompting. The best way to achieve this goal is to place a child’s study and computer desk in front of a window rather than a wall. During these periods of rest, frequent blinking can also help bypass the symptoms of digital eye strain caused by decreased blink rate caused by dry eye evaporation.
The next level of therapy is the visual one. The ideal optical therapy remains controversial and requires further study, but all agree that full correction of distance refraction with frequent upgrade to new fully corrected glasses is preferred. This means that as myopia progresses, the child needs to be looked after by an ophthalmologist with an interest in and knowledge of progressive myopia. Some clinicians prefer single vision glasses or contact lenses, some bifocal or varifocal glasses or contact lenses, some orthokeratology, and each year more special glasses and contact lenses specifically designed to treat progressive myopia become available. Although optical recommendations vary, adequate monitoring and optical correction of progressive myopia with regular prescription corrections are essential.
The third adjunct to treatment is pharmacological therapy for progressive myopia. My first encounter with this treatment method was the use of 1% atropine sulfate drops in the 1970’s by John Dyer, MD, a prominent pediatric ophthalmologist at the Mayo Clinic. Side effects were significant and many patients became intolerant, but effectiveness was evident in reducing the rate of myopia progression. The important Singapore National Eye Center studies by Donald Tan, MD, and colleagues have shown that even lower concentrations of atropine eye drops are effective. Most market leaders in this field use concentrations between 0.01% and 0.1%.
Today, there are no FDA-approved and labeled eye drops to treat progressive myopia, so current therapy requires the use of atropine drops prepared by prescription from a specialty pharmacy. I have been advised by reliable sources that well over 1 million prescriptions for low dose atropine drops in America have been filled by these specialist compounding pharmacies. Several companies around the world are involved in well-designed clinical trials seeking regulatory approval. In the US, the interested reader can look at the websites of Eyenovia, Ocumension Therapeutics, Sydnexis and Vyluma.
I believe that it will be important to enroll all young myopes aged 4-5 in an ophthalmologist’s office and treat them appropriately until their myopia stabilizes, which may be into their mid-20’s. We will learn more every year as this therapeutic area attracts significant human and financial capital as the overall progressive myopia addressable market is extremely large. The amazing cycle of innovation is about to work its magic for the progressive myopic.