BACKGROUND

The prevalence of myopia in the US has increased nearly 70% over the past 2 generations, going from 25% of the population in 1972 to about 42% in 2022. ¹  The higher rates are most notable among US children, where myopia prevalence is soaring with one report finding 59.0% of 17- to 19-year-olds myopic.² In many countries myopia is already considered an epidemic, with rates exceeding 90% in parts of Asia.^3,4

The diagnosis of childhood myopia is especially alarming given that the earlier myopia appears the more vulnerable the patient is to develop severe myopia in adulthood. Slowing myopia progression provides hope against the development of sight threatening sequelae associated with myopia such as glaucoma, retinal detachment, cataracts, and myopic maculopathy.

The landmark Collaborative Longitudinal Evaluation of Ethnicity and Refractive Error (CLEERE) Study concluded that myopia can be predicted in a nonmyopic child using a simple, single measure of refractive error and that prevention of myopia should target the child with low hyperopia as the child at risk.⁵

Future myopes show less hyperopic refractions for up to 4 years before onset of myopia compared with age matched cohorts who stayed emmetropic. A study that included more than 4500 ethnically diverse, children in the U.S. found that first grade (age 6) children with +0.75 diopters (D) or less by cycloplegic refraction had increased risk of becoming myopic between second and eighth grades (ages 8-14 years) compared with those with +0.75 D or greater. Myopia risk was found to be significant, when the refraction is +0.50 D or less for ages 7 to 8 years, +0.25 D or less for ages 9 to 10 years, and emmetropia for age 11 years.⁶

To make matters worse, during the recent COVID pandemic, myopia rose significantly for children aged 6 (21.5% vs 5.7% pre-COVID), for age 7 (26.2% vs 16.2% pre-COVID), and 8 (37.2% vs 27.7% pre-COVID). A substantial myopic shift (−0.3 diopters) occurred after home confinement for children aged 6 to 8 years. The prevalence of myopia increased 1.4 to 3 times in 2020 compared with the previous 5 years.⁷

METHODS

Given these population prevalence rates we wondered what the child population at risk for myopia looks like for a typical optometric practice. To answer this, we turned to the GPN database and sampled 2,000 practices disturbed across the US. Looking at years 2021 and 2022 we reviewed prescription data for nearly 4.7 million patients.

RESULTS

Breaking out the results by the 9 US Census Divisions, we see an average of 6.9% of patients in the sample practices are under age 12.  The percent ranged from 4.6% in New England practices to 9.3% for practices in the West South-Central states. 

Using the at-risk criteria by age and mean spherical equivalent among the under 12-year-olds in the sample practices, an average 66.2% are at risk for myopia. The at-risk percentage ranged from 60.3% in practices situated in the East North Central states to 74.6% in the Mid-Atlantic states.  

DISCUSSION

With 2/3 of children under 12 seen in optometric practices at-risk for myopia there is great need (and opportunity) to provide preventive care. The goal is early intervention to slow the progression of myopia during childhood development. 

There are a host of interventions aimed at reducing childhood myopia that include specialty contact lenses, pharmaceutical agents, designed spectacle lenses that optometrists can prescribe to slow myopic progression while also building patient loyalty.  It’s encouraging to learn that 87% of doctors in an AOA survey reported discussing myopia management techniques with parents when the child was between 5 and 8 years of age. The average age was 5.5 years. However, the same survey reported that 73% of the ODs believe an annual progression of 0.5 to 0.75 diopters was warranted before initiating myopia management protocols. According to the criteria for early intervention that may be too late. Following the early intervention guidelines and close follow-up is good for successful patient outcomes and practice success.

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References

¹ Vitale, S et al. 2009. Increased prevalence of myopia in the United States between 1971-1972 and 1999-2004. Arch Ophthalmol 127(12): 1632-1639.
² Myopia prevalence and risk factors in children – PubMed (nih.gov)
³ Morgan, IG, et al. 2012. Myopia. The Lancet 379: 1739-1748.
⁴ Lin LLK, et al. 2004. Prevalence of myopia in Taiwanese schoolchildren: 1983 to 2000. Ann Acad Med Singapore 33: 27-33.
⁵ JAMA Ophthalmol. doi:10.1001/jamaophthalmol.2015.0471
⁶ Gifford KL, Richdale K, Kang P, et al. IMI– Clinical Management Guidelines Report. Invest Ophthalmol Vis Sci. 2019;60:M184–M203. https:// doi.org/10.1167/iovs.18-25977
⁷ https://jamanetwork.com/journals/jamaophthalmology/fullarticle/2774808