High-degree myopia related to increased glaucoma risk: Study

Korea: A recent study in the American Journal of Ophthalmology has found that every myopia category, including low, moderate, moderate-to-high, and high, was substantially and dose-dependently related to an elevated risk of glaucoma.

According to the study, for each unit (1 D) increase in myopia, the risk of glaucoma increases by approximately 20%. In high degree myopia, the risk increases more steeply, representing a significant non-linear relationship.

Myopia is a growing public health concern, particularly in East Asia, where it has already reached epidemic proportions. Glaucoma is the primary cause of permanent blindness globally, with open-angle glaucoma (OAG) being the most common kind. 

With the purpose to test the dose-response relationship between myopia and the risk of OAG, Ahnul Ha, and the team from Korea looked through the PubMed, EMBASE, and Cochrane databases for population-based studies published between November 30, 2020, and November 30, 2021, that reported on both myopia and OAG. Pooled odds ratios (OR) and 95 percent confidence intervals were calculated using random-effect models (CIs). Influence and subgroup analysis supported the robustness of the results. The OAG risk per unit dosage of myopia (spherical equivalent [SE] drop of 1 diopter [D]) was estimated and assessed in a two-stage dose-response meta-analysis (DRMA).

According to this meta-analysis, myopia patients have nearly a twofold chance of getting OAG when compared to individuals who do not have myopia. Furthermore, the DRMA depicted the link between myopia and OAG risk as a concave upward slope, with the risk escalating from –6 D and accelerating further from –8 D. Researchers discovered that when the degree of myopia grew from low to high, the chances of acquiring OAG increased steadily from 1.504 to 4.142. Notably, the non-linear dose-response association of myopia with OAG in the DRMA revealed an increased risk in high myopia.

In conclusion, the findings point to a non-linear link between them, with higher-degree myopia resulting in a steeper rise in glaucoma risk. Individuals with myopia, regardless of degree, should be made more alert of glaucoma. Given the sharply growing risk associated with high-degree myopia, more attentive monitoring is required in myopia worse than –6 D.

Reference:

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. In American Journal of Ophthalmology. Elsevier BV. https://doi.org/10.1016/j.ajo.2021.10.007