To estimate the probability of high myopia-associated glaucomatous or glaucoma-like optic neuropathy (GLON) and non-glaucomatous optic neuropathy (NGON) using data from the Two-Continent Eye Study.
Approach:
Study Design: The study analyzed data from five population-based cohorts, including 35,167 eyes from 17,996 individuals aged six to 100 years.
Assessment Methods: Participants underwent refractometry, ocular biometry, optic nerve and macular photography, OCT, and perimetry.
Definitions: GLON was defined by glaucomatous optic nerve head abnormalities; NGON was defined by normal rim configuration with signs of optic atrophy.
Statistical Analysis: The study population was divided into development and validation cohorts to derive and validate equations for estimating GLON and NGON probabilities.
Key Findings:
GLON was present in 2.7% of eyes and NGON in 0.3%.
Most GLON eyes had intraocular pressure of 21 mm Hg or below.
In the validation cohort, equations achieved areas under the ROC curve of 0.881 for GLON and 0.964 for NGON.
Estimated GLON probability for a non-Indian individual with axial length of 28 mm increased from 3.5% at age 30 to 60.2% at age 75.
Interpretation:
The equations provide estimates of optic nerve risk in highly myopic patients, particularly those with long axial lengths.
Limitations:
The data are cross-sectional rather than longitudinal.
Axial length was assumed to remain constant over time.
The model was not externally validated.
Other factors, such as family history of glaucoma, were not included.
Conclusion:
The study provides a framework for assessing optic nerve risk in highly myopic patients.
