Positive and Negative Associations of Myopia with Ocular Diseases in Population-Based Studies

Abstract

ObjectivePrevalence of myopia and vision impairment due to myopic macular degeneration and myopia-related optic neuropathies have markedly increased worldwide. We evaluated whether myopia is associated with the prevalence of other ocular disorders in a positive or negative sense. DesignPopulation-based studies conducted in Russia, China and India. ParticipantsThe Russian Ural Eye and Medical Study (UEMS) and the Beijing Eye Study (BES) included 5899 individuals and 4439 individuals (all aged 40+ years), respectively, and the Central India Eye and Medical Study (CIEMS) consisted of 4711 individuals, aged 30+ years. The studies were conducted in rural and urban regions in Bashkortostan/Russia, Nagpur/India, and Beijing/China. MethodsThe participants underwent a series of ophthalmological and general medical examinations. Main Outcome MeasuresAxial length as surrogate for myopia, and prevalence of diabetic retinopathy (DR), age-related macular degeneration (AMD), angle-closure glaucoma (ACG), and open-angle glaucoma (OAG). ResultsIn the UEMS, DR prevalence (OR:0.73;95%CI:0.56,0.96), AMD prevalence (OR:0.85;95%CI:0.74,0.98) and ACG prevalence (OR:0.72;95%CI:0.55,0.95) decreased, and OAG prevalence (OR:1.65;95%CI:1.45,1.88) increased with longer axial length in multivariable analyses. In the CIEMS, lower AMD prevalence (OR:0.81;95%CI:0.69,0.95) and lower ACG prevalence (OR:0.55;95%CI:0.36,0.83), and higher OAG prevalence (OR:1.45;95%CI:1.15,1.83) were associated with longer axial length. DR prevalence (0.33%;95%CI:0.16,0.50) was too low for statistical analysis in the CIEMS. In the BES, prevalence (OR:0.64;95%CI:0.50,0.81) and 10-year incidence of DR (OR:0.48;95%CI:0.33,0.71) and prevalence (OR:0.83;95%CI:0.77,0.89) and 5-year incidence of AMD (OR:0.996;95%CI:0.993,0.999) decreased, and prevalence (OR:1.35;95% CI:1.17,1.56) and 10-year incidence of OAG (OR:1.40;95%CI:1.22,1.61) increased with longer axial length. In all three studies, the association between higher OAG prevalence and longer axial length was nonlinear with a slight increase for the moderate myopia range, and a steep increase in the highly myopic range. Conclusions and RelevanceMyopia is associated with a lower prevalence of DR, AMD and ACG and lower incidence of DR and AMD, while high myopia more than moderate myopia is associated with a higher prevalence and incidence of OAG. Future studies may assess whether in myopia, in particular in moderate myopia, the myopia-related advantages, i.e., lower prevalence of DR, AMD and ACG, may outweigh the increased risks for OAG and other myopia-related disorders.