February 1, 2022
By Dwight Akerman, OD, MBA, FAAO, FBCLA, FIACLE
Glaucoma is the leading cause of irreversible blindness worldwide, and open-angle glaucoma (OAG) is the most prevalent form of the disease. Myopia is a well-established risk factor for OAG, the association between them having been thoroughly investigated. However, the evidence on the association of myopia degree with increased risk of OAG is contradictory. The purpose of this meta-analysis was to verify the dose-response relation between the degree of myopia and OAG risk in an ethnically diverse population.
The meta-analysis comprised 24 studies in 11 countries (514,265 individuals). The pooled odds ratio (OR) of any myopia degree’s association with OAG was 1.88 (95% CI, 1.66-2.13: I2 = 53%). The OR differences based on ethnicity (Asians vs. Westerners) or five geographic areas were not statistically significant (P = .80 and P = .06, respectively). The pooled ORs of the associations between low, moderate, moderate-to-high, high myopia, and OAG were 1.50 (95% CI, 1.29-1.76), 1.69 (95% CI, 1.33-2.15), 2.27 (95% CI, 1.74-2.96), and 4.14 (95% CI, 2.57-6.69), respectively. According to the dose-response meta-analysis, the pooled OR (per SE 1.00D change) was 1.21 (95% CI, 1.15-1.28). The OAG risk accelerated at approximately −6.00D and further accelerated from −8.00D, showing a nonlinear concave upward slope (P = .03).
The meta-analysis suggests that individuals with myopia have an approximately doubled risk of developing OAG compared to those without myopia. The increased risks of OAG were consistent between Asian and Western populations. Furthermore, the authors concluded that for each 1.00D increase in myopia, the risk of OAG increases by approximately 20%. The risk more steeply increases in high-degree myopia, representing a significant nonlinear relationship.
From a public health perspective, myopia and glaucoma are among the most prevalent and rapidly increasing eye diseases causing vision impairment and blindness globally. There should be increased awareness of glaucoma among individuals with myopia, regardless of its degree. Notably, more vigilant monitoring is needed in myopia −6.00D or greater given the steeply increasing risk incurred in high-degree myopia.
Abstract
Degree of Myopia and Glaucoma Risk: A Dose-Response Meta-Analysis
Ahnul Ha, Chung Young Kim, Sung Ryul Shim, In Boem Chang, Young Kook Kim
Purpose: To verify the dose-response relation between the degree of myopia and open-angle glaucoma (OAG) risk.
Design: Dose-response meta-analysis.
Methods: We searched the PubMed, EMBASE, and Cochrane Library databases for population-based studies published until November 30, 2020, and reporting on both myopia and OAG. Random-effect models generated pooled odds ratios (OR) and 95% CIs. Results robustness was confirmed by influence and subgroup analyses. A 2-stage dose-response meta-analysis calculated the OAG risk per unit dose of myopia (spherical equivalent [SE] decrease of 1 diopter [D]) and examined the relationship pattern.
Results: The meta-analysis comprised 24 studies in 11 countries (514,265 individuals). The pooled OR of any myopia degree’s association with OAG was 1.88 (95% CI, 1.66-2.13; I2 = 53%). The OR differences based on ethnicity (Asians vs. Westerners) or 5 geographic areas were not statistically significant (P = .80 and P = .06, respectively). The pooled ORs of the associations between low, moderate, moderate-to-high, high myopia, and OAG were 1.50 (95% CI, 1.29-1.76), 1.69 (95% CI, 1.33-2.15), 2.27 (95% CI, 1.74-2.96), and 4.14 (95% CI, 2.57-6.69), respectively. According to the dose-response meta-analysis, the pooled OR (per SE 1-D change) was 1.21 (95% CI, 1.15-1.28). The OAG risk accelerated at approximately -6 D and further accelerated from -8 D, showing a nonlinear concave upward slope (P = .03).
Conclusions: For each unit (1-D) increase in myopia, the risk of glaucoma increases by approximately 20%. The risk more steeply increases in high-degree myopia, representing a significant nonlinear relationship.
Ha, A., Kim, C. Y., Shim, S. R., Chang, I. B., & Kim, Y. K. (2021). Degree of myopia and glaucoma risk: a dose-response meta-analysis. American Journal of Ophthalmology.
DOI: 10.1016/j.ajo.2021.10.007