Long-term multistep treatment needed for progressive myopia
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Myopia is the most common refractive error in the United States and globally. Today, about 42% of Americans, or 141 million individuals, are myopic.
I have written perspectives on the management of progressive myopia twice before. In the Aug. 10, 2021, issue of Healio/Ocular Surgery News, my perspective discussed the need to identify myopia at an early age as we now have effective therapies to reduce myopia progression. And in the May 10, 2022, issue, my perspective emphasized the fact that even low levels of myopia increase the risk for developing significant sight-threatening ocular pathology including cataract, glaucoma, retinal detachment and myopic maculopathy.
We have all learned in glaucoma management that every millimeter of mercury reduction matters in reducing the risk for progressive optic nerve damage. In myopia, every diopter of myopia reduction also matters, decreasing the risk for vision-threatening problems in later life. I will disclose that myopia management is an area of personal interest, and I consult with industry in this field. My early career interest was in the surgical treatment of preexisting myopia, including refractive corneal surgery, refractive cataract surgery and phakic IOLs. My current interest is in reducing the impact of the current global pandemic of progressive myopia. I will share three thoughts, some of which are personal opinions and may be controversial.
First, I consider progressive myopia an acquired and potentially treatable disease, not just a refractive error that can be managed with optical correction. The risk for vision loss a patient faces with 6 D or more of myopia is far greater than the risk they face with no or 1 D to 2 D of myopia. I believe eye care professionals should do all they can to reduce the incidence and severity of myopia in children, adolescents and young adults by reducing myopia progression.
Few patients are born with myopia. In one study of 12,237 newborns, only 0.45% were myopic at birth, and most of those were premature deliveries. The typical measured refraction in a newborn is +0.5 D to +4 D of hyperopia. At age 3 years, children typically refract between plano to +1.75 D, and at age 5 years, plano to +1.25 D. A mild hyperopic refraction, if symmetrical, presents no difficulty to a child as they have a large accommodative reserve. This means the presence of even mild myopia at age 5 years when preschool visual screening becomes more accurate is abnormal and requires referral to an eye care professional (ECP) and treatment to reduce progression.
In my opinion, myopia of –0.5 D in a 5-year-old should generate an ECP examination and an ECP-to-parent discussion followed by initiation of therapy to reduce myopic progression. Myopia of –0.5 D or more in a 5-year-old is by definition progressive myopia in 99.55% of patients. The goal of the ECP, child and parents is to reduce myopia progression as much as possible. As treatment tools, we have behavioral modification, which includes outside play of 1 to 2 hours a day and the so-called 20-20-20 rule in which a 20-second distance gaze at something 20 feet or more away is encouraged after every 20 minutes of near work. Adding rapid blinking and forced lid closure to this habit can also positively impact the incidence of computer vision syndrome. This is a good habit for everyone but especially the progressive myope. It can be taught even to young children.
Second, proper optical correction is important, and specialty glasses and contact lenses along with orthokeratology are utilized by many ECP experts in the field. Full correction of the refractive error is desirable, whether with spectacles or contact lenses. Regular eye examinations are required to monitor for myopia progression. Home screening devices that can measure refraction and axial length on an iPhone are being developed by several companies, including OcuDoc Mobile (OcuDoc), and these home monitoring devices will help patients know when to contact their ECP for follow-up care.
Medical therapy with low-concentration topical atropine drops once daily are showing promise globally. While there is still much to learn, my reading of the global literature suggests that 0.01% to 0.05% topical atropine drops are therapeutically effective with a reasonable side effect profile. The typical side effects are pupil dilation with secondary light sensitivity or photophobia along with the expected cycloplegia with reduced accommodative amplitude. These mild side effects are well tolerated by the majority treated with low-dose atropine eye drops. As expected, higher concentrations of atropine eye drops seem to offer higher efficacy but also have more side effects. Just like in glaucoma, the ideal concentration and frequency of topical atropine eye drops and follow-up visits are appropriately personalized for each patient by their ECP. While there is much to learn, current studies and ECP experience suggest the benefit of behavioral modification, proper optical correction and topical atropine therapy are additive and synergistic.
My final thought is likely the most controversial: the duration of therapy. How long do progressive myopes need to be on therapy to minimize their eventual level of myopia? Unfortunately, I believe the evidence suggests that therapy may be required for decades. As a refractive surgeon, it was obvious to me that myopia progressed significantly for many of my patients while completing college and postgraduate studies. In my later years of practice, I encouraged my patients to delay refractive corneal surgery until they completed their schooling.
In the PERK study of radial keratotomy, with patients in their 30s, nontreated second eyes progressed 1 D over 10 years, or 0.1 D a year. Several demographic studies suggest myopia progression often continues until age 40 years and in select cases even longer. The rate of myopia progression definitely declines with age, but if every diopter of myopia matters, some patients may require therapy for 2 to 3 decades to minimize their myopia. Again, therapy is ideally directed by an ECP and personalized for every patient. Hopefully, behavioral modification and proper optical correction will be enough for the older patients with progressive myopia, but topical atropine therapy may be needed for some until they complete their education at age 25 to 30 years.
Progressive myopia is a treatable disease, and it deserves treatment. Every progressive myope is ideally captured by an ECP by age 5 years and treated as appropriate using a personalized therapeutic regimen including behavioral modification, proper optical correction and, in most, low-concentration atropine eye drops. I believe treatment of progressive myopia will create a major new vertical in eye care to the benefit of patients, eye care professionals and industry.
- References:
- Therapeutic pyramid guides treatment of progressive myopia. https://www.healio.com/news/ophthalmology/20220503/therapeutic-pyramid-guides-treatment-of-progressive-myopia. Published May 6, 2022. Accessed May 31, 2023.
- Treatment of progressive myopia needs to begin as early as possible. https://www.healio.com/news/ophthalmology/20210727/treatment-of-progressive-myopia-needs-to-begin-as-early-as-possible. Published Aug. 2, 2021. Accessed May 31, 2023.
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