# Epidemiology of pathologic myopia in UK adults with high myopia

## TL;DR

This study finds that nearly half of UK adults with high myopia have pathologic myopia, mostly with mild symptoms, and myopia severity is the only modifiable risk factor.

## Contribution

The first cross-sectional epidemiological investigation of pathologic myopia in UK adults with high myopia.

## Key findings

- 41.7% of participants with high myopia had pathologic myopia in at least one eye.
- Diffuse chorioretinal atrophy was the most common manifestation of pathologic myopia.
- Myopia severity is the only modifiable risk factor associated with pathologic myopia.

## Abstract

To conduct the first cross-sectional epidemiological investigation of pathologic myopia (PM) in UK adults with high myopia.

Fundus photographs of 3024 highly myopic eyes (spherical equivalent refraction (SER) ≤−5.00D) from 2000 randomly sampled adults (aged 40–70 years) in the UK Biobank were double graded by an ophthalmic reading centre using the Meta-analysis for Pathologic Myopia framework. Adjudication was performed by one of two retinal specialists. Multivariable mixed-effects logistic regression was used to explore potential risk factors and fundus biomarkers—initially adjusting for SER, age and sex, before including these and other variables with p<0.10 in a single model.

PM was present in 1138 of 3006 gradable fundus photographs, with 41.7% (95% CI 39.5% to 43.9%) of participants affected in at least one eye graded. Most eyes with PM exhibited diffuse chorioretinal atrophy (97.4%), while the more severe stages—patchy chorioretinal atrophy and macular atrophy—were observed in only 24 and 5 eyes, respectively. 13 eyes had ‘plus’ lesions or suspected staphyloma. Factors independently associated with increased odds of PM (all p<0.05) included decreasing SER (adjusted OR: 0.22, 95% CI 0.15 to 0.32), older age (2.20, 1.63 to 2.97), female sex (1.87, 1.12 to 3.12), lower deprivation (0.73, 0.56 to 0.94), white ethnicity (52.3, 17.3 to 158.3), lower retinal arteriovenous ratio (0.47, 0.37 to 0.58), increased retinal vascular complexity (4.60, 3.16 to 6.70) and a relatively horizontal disc orientation (2.98, 1.88 to 4.72). None of the explored modifiable lifestyle or health-related variables were associated with PM.

PM prevalence is high among mid-life adults with high myopia in the UK Biobank, although most cases are relatively mild (diffuse chorioretinal atrophy). The only modifiable risk factor identified is myopia severity.