Globally, the prevalence of myopia is increasing at an alarming rate, seen in the increase of dependence on related refractive correction, such as glasses, and significant increases in the risks for vision impairment from conditions associated with higher levels of myopia, such as retinal damage, cataracts and glaucoma.¹ In the United States, the incidence rate of myopia jumped to 41.6% for the years 1999-2004, as compared to 25% for the years 1971-1972.²

As optometrists seek to keep up with the demand of myopia control, and the related clinical research, it can be hard to know where to start.

Here, I discuss the basics of myopia, how one might discuss the condition with a patient’s parents and how to find demographic information that can best help inform your business plan.

THE BASICS

The World Health Organization (WHO) defines myopia as “a condition in which the spherical equivalent objective refractive error is greater than or equal to -0.50 D in either eye” and high myopia as “a condition in which the spherical equivalent objective refractive error is greater than -5.00D in either eye.”¹ More recently myopia has not only been categorized into quantitative traits, but also into descriptive subsets. The descriptive traits include “pre-myopia, myopia, secondary myopia, axial myopia, and refractive myopia.”³

Using the current research, optometrists can be alert to demographic and environmental factors that may put their individual patients at higher risk for progressing to high myopia.

Myopia affects more than 25% of Americans, with consistent demographic trends observed, including younger age, female sex, Asian descent and family history of myopia.^4,5

While demographics is generally the study of the population based on sex, race and age, it also refers to socioeconomic information, including environmental factors a population may be more exposed to. For example, myopia has also been seen to be more prevalent among people who have advanced academic training, due the environmental factor of excessive near work.⁶

The genetic component has generally been considered a small contributing factor, although genes may be directly related to the susceptibility of the environmental influences.⁷ A few optical influences from our environment were identified as possible causes for the onset and continued progression of myopia, specifically the amount of near work and time spent indoors.^8,9 One study found a significant association between outdoor activity time and a primary-school aged child’s spherical equivalent; children who spent more hours outdoors were found to be relatively less myopic than their peers.⁹

THE PARENT DISCUSSION

When discussing myopia with patients, I recommend going back to the basics: “Myopia is a common refractive error where the ocular system does not refract light properly. It tends to occur when the eye is longer than typical. As a result of these anatomical variations, the light rays converge in front of the retina, instead of on it. Myopia can be broken into low myopia and high myopia. High myopia is associated with earlier onset. All myopia can be addressed with basic refraction correction, however, earlier onset myopia requires a more aggressive approach, such as the overnight wear of special contact lenses, special soft lenses, or nightly drops, and we’ll be on the lookout for this form with your child.”

In discussing the possibility of myopia progression with patients, optometrists might find it helpful to use statistics about the changes the eye can go through as they age. Specifically, less than 5% of people who are age 5 are myopic. The percentage increases to 25% by the late teens; 35% for young adults and 42% for the middle-aged. From there, the amount of myopia decreases to 20% by age 65, and less than 13% by age 80.¹⁰

Finally, given the environmental factors that place patients at risk, discussions with parents should also include suggestions on moderating the amount of time participating in near work and the importance of outdoor activities each day.

FIND/UTILIZE DEMOGRAPHIC INFORMATION

Understanding the demographics of the population in relation to the location of one’s practice is useful for a variety of reasons, including knowing how to best include myopia management in a practice’s business plan, such as allotting for marketing dollars.

The U.S. Census Bureau has a portal that allows public access to community-specific information. Optometrists are able to search by city or zip code and can acquire the latest statistics pertaining to the demographics of their practice’s area. The U.S. Census for your area can be accessed simply by going to https://data.census.gov and entering in the zip code you want demographic information for.

The statistics include everything from total population, broken down to ages (by five-year increments from 0 to 85 years and over), sex ratio, race distribution, socioeconomic status, as well as housing estimates. Local and county websites also have information of regionally collected statistics.

If optometrists are considering a specialty in high myopia, they’ll want to know this information to make an informed decision. Additionally, O.D.s should evaluate whether this makes a sound business decision, based on the published research, which continues to grow.

For example: Practice owner A is located in an affluent suburb of a major city on the West Coast of the United States. It is a popular place for personnel from a local university to be housed. Demographic information shows multiple family homes with heads of household who have advanced degrees and a significant Asian population. Practice owner B opened her practice in a rural Midwestern town with a significantly older population of more men than women. Based on this demographic information, Practice owner A is likely to see great need and opportunity for a specialty in high myopia. Meanwhile, Practice owner B might choose not to dedicate a full niche business plan to high myopia and instead, stay current on the research of myopia, including how myopia relates to seasonal changes, as that’s likely a prevalent risk factor for much of her population.

MEET YOUR PATIENTS’ NEEDS

Myopia progression studies are being done at an incredible volume and pace. They have shown promising results heavily dependent on demographic factors. Using the information that we have available by our U.S. Census Bureau and local government agencies can benefit us greatly and allow us to stay on the very edge of patient care. OM

REFERENCES

1. The Impact of Myopia and High Myopia, Report of the Joint World Health Organization- Brien Holden Vision Institute Global Scientific Meeting on Myopia. University of New South Wales, Sydney, Australia 16-18 March 2015.
2. Vitale S, Sperduto RD, Ferris Fl. Increased prevalence of myopia in the United States between 1971-1972 and 1999-2004. Arch Ophthalmol. 2009 Dec;127(12):1632-9. doi: 10.1001/archophthalmol.2009.303.
3. Flitcroft DI, He M, Jonas JB, et al. Imi - Defining and Classifying Myopia: A Proposed Set of Standards for Clinical and Epidemiologic Studies. Invest Ophthalmol Vis Sci 2019;60:M20-M30.)
4. Facts About Refractive Errors. NEI. October 2010. Archived from the original on 28 July 2016. Retrieved 30 July 2016. https://www.nei.nih.gov/learn-about-eye-health/eye-conditions-and-diseases/refractive-errors Accessed April 2020.
5. Eye Disease Prevalence Research Group, The prevalence of refractive errors among adults in the United States, Western Europe, and Australia. Arch Ophthalmol 2004;122495- 505.
6. Rosner M, Belkin M. Intelligence, Education, and Myopia in Males. Arch Ophthalmol 1987;105:1508-11.
7. Holden B, Fricke TR, Wilson DA, et al. Global prevalence of myopia, high myopia, and temporal trends from 2000 to 2050. Ophthalmology. 2016 May;123(5):1036-42. doi: 10.1016/j.ophtha.2016.01.006. Epub 2016 Feb 11.
8. Ghosh A, Collins MJ, Read SA, Davis BA, Chatterjee P. Axial elongation associated with biomechanical factors during near work. Optom Vis Sci. 2014;91:322–9.
9. Lin Z, Vasudevan B, Jhanji V, et al. Near work, outdoor activity, and their association with refractive error. Optom Vis Sci. 2014;91:376–82.
10. Mutti DO, Zadnik K. Age-Related Decreases in the Prevalence of Myopia: Longitudinal Change of Cohort Effect? Invest Ophthalmol Vis Sci. 2000;41(8): 2103–07.

DR. VIRANI is an optometrist at Kleiman Evangelista Eye Center in Dallas. She is a consultant for Alcon and can be reached at drvirani@keec.com.