This article was originally published in a sponsored newsletter.

Pathological myopia (PM) can be a cause of irreversible vision loss. The presence of various complications in the posterior segment, including posterior staphylomas, myopic maculopathy, or associated optic neuropathy, indicate its main difference from high myopia.¹ An international panel of myopia researchers recently conducted a review resulting in the introduction of a simplified and standardized classification system called Meta-analysis for Pathological Myopia (META-PM).² According to META-PM, PM is defined as the presence of chorioretinal atrophy that is equal to or more severe than diffuse atrophy.²

On the other hand, high myopia is defined as a high degree of myopic refractive error of at least –5.00D.¹ It is important to note that PM has a higher correlation in eyes that have high myopia, but some patients who have low myopia or emmetropia can also develop pathological myopia.¹

There is an increasing incidence of childhood or “school myopia,” likely because of excessive near work and increased screen time.³ As a result, there is an anticipated rise in the prevalence of high myopia as well.³ However, it remains unclear whether PM will also increase.^2,3 Additionally, researchers are still examining which genes are responsible for myopia and whether these genes are different in patients who have PM.²

The prevalence of patients who have PM is 1% to 19% in the low-to-moderate myope population (< –3.00D), but is as much as 50% to 70% in the high myopia population.¹There is a 67% increase in the risk for PM with every 1D increase in myopia.¹ This linear trend is observed until around –7.00D when it becomes an exponential trend with subsequent increases in myopia.¹

Although the prevalence of PM is low in children, it increases with advancing age. Individuals 40 years and older who have high myopia showed a progressive increase in PM prevalence and degree of maculopathy.¹ A long-term study showed that 83% of adults who developed myopic maculopathy already had diffuse choroidal atrophy around the optic disc in childhood.⁴ This finding suggested that children who develop PM may be structurally different from an early age.

It is unclear whether the risk of developing PM depends on patients’ genetic backgrounds or whether mechanical stress and ischemia with aging play a role.^1,2There is no conclusive evidence that school myopia progresses to PM; some studies indicate the latter exhibits different characteristics during childhood.⁴ Genetic studies will face the challenge of determining if there are genes associated with myopic maculopathy independent of high myopia.² Although the precise etiology of PM remains uncertain, the observed correlation between high myopia and PM suggests that effective myopia management strategies may have potential benefits in reducing the risk of developing pathological myopia.

So, how do you know whether a child’s myopia will progress to PM before they develop it? We don’t. Should you treat every child with myopia just in case? That is the question we all need to ask ourselves.

1. Ohno-Matsui K, Wu PC, Yamashiro K, et al. IMI Pathologic Myopia. Invest Ophthalmol Vis Sci. 2021 Apr 28;62:5.

2. Ohno-Matsui K, Lai TY, Lai CC, Cheung CM. Updates of pathologic myopia. Prog Retin Eye Res. 2016 May;52:156-187.

3. Ohno-Matsui K. WHAT IS THE FUNDAMENTAL NATURE OF PATHOLOGICAL MYOPIA? Retina. 2017 Jun;37:1043-1048.

4. Yokoi T, Jonas JB, Shimada N, et al. Peripapillary Diffuse Chorioretinal Atrophy in Children as a Sign of Eventual Pathologic Myopia in Adults. Ophthalmology. 2016 Aug;123:1783-1787.