Optometry Myopia Management
By Dennis Leung O.D., F.I.O.A.M.C.
It’s estimated that by 2050 more than 50% of the world population will be myopic1. About 10% of the myopes in the world are high myopes of more than 5 diopters. High myopia is associated with many sight-threatening eye diseases such as retinal detachment, glaucoma, and myopia maculopathy among others.
Traditionally, optometry has managed myopia with only a palliative approach. For example, we prescribe glasses and contacts for refractive errors. For our adult patients, we may recommend refractive surgery and co-manage these cases. That was about as far we would go in treating myopia.
Today, due to the advent of many effective treatment options for myopia progression, and along with an awareness of the many irreversible diseases associated with high myopia, optometrists can no longer remain passively on the sidelines. The paradigm has changed. It is now our professional, if not legal responsibility, to educate our patients and recommend early intervention in the progression of myopia in children.
It is now known that once a child becomes myopic, the elongation of the axial length also accelerates. The axial length of younger children tends to increase faster than older children. The increase of myopia is likely to slow down more significantly during the late teens, but in some myopes, especially persons of Asian descent, the progression continues to young adulthood. Therefore, we are facing a very large patient population that needs timely myopic treatment intervention. The optometric crusade for myopia control is clearly justified and needed.
Proven treatment options for myopic progression in children can be categorized into five different modes: nightwear orthokeratology, soft multifocal contacts, pharmaceuticals, ophthalmic lenses, and lifestyle changes for our young patients.
Nightwear Orthokeratology allows many myopic children to see well during the day without glasses nor contacts, and also slows down myopic progression among children in many prospective and retrospective studies. It has been the gold standard for myopia control for many years. Over time, improvements in the manufacturing technology for these reverse geometry lenses, and lens designs, has further improved treatment effectiveness. One should expect a close to 50% controlling effect when Ortho-K is utilized for myopia management2,3,4. Although Ortho-k lenses such as CRT and others are not FDA approved for myopia control, they are routinely prescribed off-label by many proactive eye care practitioners.
Soft multifocal lenses, much like Ortho-k lenses, alter the corneal shape, enabling the eye to project light images with a myopic defocus shell onto the retina which is believed to be the mechanism that causes the decrease in myopia progression. Just this year, the FDA approved MISIGHT multifocal daily use soft lenses with an indication for slowing down childhood myopia progression. The MISIGHT lens design contains two concentric defocus rings to give the necessary periphery myopia defocus necessary to slow down axial length increase by more than 50% based on a well-designed three-year double-masked randomized study5. Besides MISIGHT lenses, many eye care providers have used off-label with good success custom designed multifocal soft lenses as well as other commercially available multifocal soft lenses indicated for presbyopia correction.
Atropine drops at a concentration of 1% has been used for decades to slow the progression of myopia. The popularity of atropine use in the U.S. at such high concentrations is very limited due to the obvious temporary side effects of photophobia and loss of accommodation. The ATOM 2 study in 2015 revealed a surprising finding that atropine at a 0.01% concentration with little or minimum visual side effect is able to slow down myopia progression by 50% with a minimum rebound rate6. In 2018, the LAMP study showed a dose-response for low concentration atropine eye drops. A 0.05% atropine concentration results in good myopia control with just minimal and mostly tolerable visual symptom7. Prescribing diluted atropine off-label to children in various concentrations has now become another available tool for the battle against myopia. Atropine can be used as a stand-alone myopia treatment as well as in combo-therapy with Ortho-k or soft multi-focal lenses for additive protection from myopia progression8.
Ophthalmic lenses have long been used for myopia control by many eye physicians. There have been studies using executive bifocals with and without prisms, as well as progressive bifocals to slow down myopia. The results of these studies are far from conclusive that ophthalmic lenses are helpful in controlling myopia via the mechanism of reducing accommodative stress and lags. The MYOSMART lens by Hoya, although not available in the U.S., has been used for several years in Hong Kong and several countries in Asia.
MYOSMART’s DIMS technology contains microscopic dots with each projecting myopia defocus images to the retina which gives a reported protective effect that slows down axial length increase by more than 50%. MYOSMART lenses will soon be available in Canada9. There are two other promising ophthalmic myopia preventive lenses on the horizon. One is DOTS lens technology developed by a company in the U.S. and KOBUTA electronic lens developed by a company in Japan. Both have shown some encouraging initial results in their studies10.
Lifestyle changes and visual hygiene advice should be provided by all eye care practitioners to all children who are susceptive to myopia and their parents. It is well-documented that exposure to sunlight is helpful in preventing rapid axial length increase especially before the onset of myopia. The recommended amount of sunlight exposure is a minimum of 12 hours per week. Although the mechanism behind the benefit of sunlight in slowing axial length growth is not yet clear, the effects of exposure to sunlight in delaying the onset of myopia is well-documented11, 12. Accommodative stress is also believed to lead to an increase in myopia by many practitioners and scientists13. Accordingly, books should not be held too close to the eyes and it is important to take frequent breaks from reading and viewing of a computer screen. This lifestyle change should be communicated to patients as part of myopia progression treatment and prophylaxis.
The treatment of progressive myopia in children should include creating a treatment plan for the patient. We need a thorough history of the patient’s lifestyle such as time outdoors and up-close work. It is also necessary to consider genetic factors such as ethnicity, gender, and family history, which are all contributory to the risk exposure for a higher degree of myopia. The degree of myopia in the child’s parents is also an important factor to consider. It is vital to creatively design a customized myopia management program for the patient to provide an optimal outcome.
The change in paradigm in optometry is that we now proactively manage myopia and its progression. We can no longer take a palliative approach as we did in the past. There is no question that genetic predisposition has much to do with myopia development. However, early intervention in the case of progressive myopia in children is mandatory for optometry as we now have many effective therapeutic tools.