Risk of Glaucoma and Undergoing Glaucoma Surgery in Myopic and Highly Myopic Eyes

PURPOSE: To evaluate the risk of glaucoma development and the necessity for glaucoma surgery among patients with myopia and high myopia. DESIGN: Longitudinal, nationwide population-based cohort study. PARTICIPANTS: A total of 14 204 347 phakic individuals 40 years of age or older with claims indicating refraction testing between September 2014 and August 2015 were followed up from September 2015 through March 2023. METHODS: Using validated algorithms, participants were classified into 3 groups based on refractive error status: nonmyopia, myopia, and high myopia (spherical equivalent ≤ -6.0 diopters). The high myopia group was considered a subset of the myopia group. The risk of glaucoma developing and the requirement for glaucoma surgery over 7.5 years were assessed through Cox proportional hazards regression, adjusting for potential confounders. MAIN OUTCOME MEASURES: The primary outcomes were the development of glaucoma and the requirement for glaucoma surgery. RESULTS: Among the 14 204 347 participants, 7 478 999 were identified as having any degree of myopia, including 373 232 patients who met the criteria for high myopia. The mean age was 68.8 years in the nonmyopia group and 56.8 years in the myopia group, with women constituting more than 60% of each group. Comorbidities including diabetes, hypertension, and dyslipidemia were more prevalent in individuals without myopia. After adjusting for age, sex, diabetes, hypertension, and dyslipidemia, the adjusted hazard ratio (HR) for glaucoma developing was 1.44 (95% confidence interval [CI], 1.43-1.45) for the myopia group and 2.67 (95% CI, 2.62-2.73) for the high myopia group. Regarding glaucoma surgery, the adjusted HR was 1.71 (95% CI, 1.67-1.75) for the myopia group and 3.07 (95% CI, 2.91-3.25) for the high myopia group. Notably, the adjusted HR for filtering surgery such as trabeculectomy was 2.03 (95% CI, 1.94-2.11) for the myopia group and 4.03 (95% CI, 3.67-4.42) for the high myopia group. CONCLUSIONS: Both myopia and high myopia significantly increase the risk of glaucoma developing and the likelihood of requiring glaucoma surgery, especially for invasive filtering surgeries. These findings suggest a need for diligent glaucoma screening and proactive management for individuals with myopia. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.