Myopia, dry eye, macular degeneration are linked to digital device use
One clinician insists these conditions are exacerbated by the increasing use of electronics.
The first personal computers hit the market in the early 1980s and have become an inescapable part of modern life – inescapable that is, until they have been replaced or augmented with smaller devices, such as the first iPhone in 2007.
Now there are rarely situations where a digital device is unavailable. With total domination of the market for media and entertainment consumption for adults, these devices have taken over the lives of younger and younger people to the point where children and toddlers are now using them to greater degrees.
Over roughly the same span of time that digital devices have taken over the world, myopia has been increasing rapidly, reaching peaks of mid-90 percentages in the countries of East Asia. One could likely match the market penetration curve of digital devices over time with the increasing prevalence of myopia and wonder if there is a cause and effect or just an interesting pseudo-correlation.
Near work and myopia, dry eye
While there have always been suspicions that near work causes myopia or worsens its progression, the evidence has been a bit sketchy. Recently, a meta-analysis involving 20,000 children in Asia was able to link the number of hours of near work with the level of myopia (Huang et al.). Other studies have linked educational levels to myopia (Mirshahi et al.), and still other studies have linked IQ to myopia (Jung et al.).
While it may take a long time to prove the effects of digital devices on refractive error development, optometrists would do their patients no harm and might help their long-term vision and ocular health if they assume that excessive digital device use may increase the risk of myopia.
Dry eye disease also appears to be increasing in prevalence, and the average age of onset appears to be decreasing. Our understanding of dry eye disease has changed dramatically from the conclusions of the first Dry Eye Workshop panel – that it is primarily caused by aqueous deficiency – to the conclusions of the second panel – that it is more likely caused by evaporative dry eye due to meibomian gland dysfunction (MGD).
The evidence that digital device usage may be contributing to dry eye syndrome and MGD is much stronger than the refractive error story. It is well established that their usage leads to decreased blink frequency as well as incomplete blinking (Cardona et al.). Other studies suggest any detailed near work will decrease blink rate, while others suggest that visual and eye discomfort symptoms are greater with digital device use (Benedetto et al.).
It is also known that macular degeneration is increasing in frequency and, while this may be due to the aging population, there is a chance that excess blue light exposure from digital devices at younger ages and for increasingly greater numbers of hours and years may increase damage to macular pigments.
Young children may be at more risk for blue light and UV light damage, as their crystalline lenses are not as effective at absorbing high energy light as older eyes.
Theory of digital device use
What I am proposing is a grand unified theory of optometry, linking digital device usage to myopia, dry eye and macular damage. It is likely that myopia specialists may not look for dry eyes in their young patients, and dry eye specialists may look neither for myopia risks nor dry eye in children. It is also likely that macular degeneration specialists have few children and young myopes in their waiting rooms.
There are a number of crucial and important parallels among all of these conditions. They are all progressively worsening conditions that lead to irreversible damage to ocular tissues, yet they all are, at least to some degree, easily preventable. Optometry has a real opportunity to dramatically improve the long-term ocular health and visual quality of their patients by thinking of these three conditions as being part of a grand unified theory of optometry.
Practitioners can begin to help their patients by looking for all these conditions in their young patients so that they can help slow myopia progression, improve the ocular surface and protect the retina. Researchers can help our understanding by broadening their lines of inquiry to include young patients in AMD and dry eye studies, to evaluate ocular surface disease and macular pigment density in myopia progression studies, and to look for all these conditions when studying the ocular and visual consequences of digital device usage.
- Benedetto S, et al. PLoS One. 2013;8:e83676. doi:10.1371/journal.pone.0083676.
- Cardona G, et al. Curr Eye Res. 2011;36:190-197. doi: 10.3109/02713683.2010.544442.
- Huang HM, et al. PLoS One. 2015;10:e0140419. doi:10.1371/journal.pone.0140419.
- International Dry Eye Workshop Committee. The Ocular Surface. 2007;5(2).
- Jung SK, et al. Invest Ophthalmol Vis Sci. 2012;53:5579-5583. doi: 10.1167/iovs.12-10106.
- Mirshahi A, et al. Ophthalmology. 2014;121(10):2047-2052. doi: 10.1016/j.ophtha.2014.04.017.
- For more information:
- Thomas Aller, OD, FBCLA, of San Bruno, Calif., is a senior project scientist for the Vision Cooperative Research Centre. He can be reached at email@example.com.
Disclosure: Aller is a member of the Treehouse Eyes board of advisors and a consultant for the Myopia Control Programme at the Brien Holden Vision Institute.