Lifelong vision correction plan has value for all involved
I like the concept of lifetime management of refractive errors. I have a few thoughts as to how this might be accomplished.
First, the patient has to be under an eye doctor’s care for a lifetime for their refractive error to be managed. Today, in the United States, that would be an ophthalmologist or an optometrist. The childhood epidemic of progressive myopia suggests to me that all children should have a baseline screening for refractive error at an early age, preferably preschool. The natural progression of refractive error is from mild hyperopia as an infant toward emmetropia or myopia as the child ages. In later years, after the age of 45 years, refractive error for the emmetrope begins to shift slightly hyperopic.
I believe children should be monitored for signs of progressive myopia beginning at least by age 5 years. According to my friend Kazuo Tsubota, MD, Japanese children with progressive myopia progress at 0.8 D per year on average, primarily between the ages of 6 and 16 years. Treatments need to be started early, as soon as a patient demonstrates any myopia, and perhaps while they are still mildly hyperopic. There is much to learn, but some combination of 2 hours or more of daily outdoor activity, atropine drops, 10-minute breaks for distance viewing every hour while on a digital device, exposure to violet light for at least some of the day, specialty contact lenses and glasses that correct peripheral defocus, treating convergence insufficiency, spectacles or contact lenses with low adds reducing accommodative demand, and perhaps orthokeratology needs to be instituted early.
We also need to screen for childhood-onset keratoconus and treat with collagen cross-linking as soon as it is diagnosed. In order to do so, the patient must be under the care of an eye care professional, and the eye care professional needs to be willing and able to make the diagnosis and institute treatment. Arguably, progressive myopia requires as much diligence in diagnosis and treatment as progressive keratoconus. We are not there yet anywhere in the world.
As a typical patient with a refractive error travels through life, they usually start with glasses. Many transition to contact lenses, usually starting around age 12 or 13 years. Refractive surgery becomes an interesting option for some patients in their 30s. So, up through the age of presbyopia, most patients either stay with glasses, go from glasses to contact lenses, go from glasses to contact lenses and on to refractive surgery, or start with glasses followed by contact lenses and then return to glasses. As we all know, there are powerful economic interests promoting all three modes of refractive correction.
We are now entering an era in which a fourth mode of refractive error correction will be emerging, the pharmacologic treatment of refractive errors. I already mentioned dilute atropine for progressive childhood myopia. Patients with mild to moderate presbyopia will also soon have the option of miotic drops. Small diameter aperture optics, as popularized in disposable cameras, allow what the camera industry has termed hyperfocality. The hyperfocality of small diameter aperture optics can also correct the blur caused by up to 1 D to 1.5 D of myopia, hyperopia and astigmatism. Small diameter aperture optic hyperfocality also enhances vision in the irregular cornea with significant higher-order aberrations.
Besides presbyopic patients, who represent nearly 2 billion globally, there are another 2 billion potential patients with low refractive errors and significant higher-order aberrations who can benefit from miotic drops. The pharmacologic management and treatment of refractive errors will, in my opinion, be a big part of our future. The drops will be prescription drops, so for a patient to access them, they will need to be under the care of an eye care professional licensed to prescribe. Again, we eye doctors need to capture and follow these patients, diagnose progressive myopia and keratoconus early, and institute treatment.
As the so-called dysfunctional lens syndrome patient progresses past the age of 55 years or so, miotic drops will not be enough to enhance reading vision, and quality of vision will start to decline as the human lens ages. Next in line is natural lens replacement. Today, a number of technologies are converging that promise to provide us with an adjustable accommodating IOL in the next decade. Once this technology is available, I believe it will become a favored treatment for the patient older than age 55 or 60 years. We, of course, have issues with retinal detachment in the high myope, but I anticipate a combination of IOL design, careful monitoring and treatment by our retinal colleagues may mitigate this issue to some extent.
A lifelong vision correction plan requires that all patients first be under the care of an eye care professional. That is the first challenge, but as we attempt to manage the global epidemic of progressive myopia in the advanced countries, I expect most citizens will be able to access an eye doctor from an early age. They should, in my opinion, be encouraged to do so. This will also help enormously in allowing early diagnosis and management of the other causes of vision loss and reduced quality of life including strabismus, amblyopia, glaucoma, cataract, ocular surface disease, diabetic eye disease and age-related macular degeneration. To me, a win-win-win for patients, eye care providers and the multiple industries that support us.
Disclosure: Lindstrom reports relevant financial disclosures with Novartis, Bausch + Lomb, Zeiss, Orasis, Harrow Health, Flying L and Visionary Ventures.