Pathologic Myopia Globe Shape and Long-Term Prognosis

Three-dimensional (3D) eye shape may play a critical role in predicting long-term structural and functional outcomes in high myopia.

To determine whether 3D eye shape subtypes defined by high-resolution magnetic resonance imaging (MRI) predict 15-year structural and functional outcomes in high myopia.

This prospective cohort study involved a subsample of individuals with high myopia (spherical equivalent ≤-6.00 D in both eyes) enrolled in the Zhongshan High Myopia Cohort at a single center in China. Participants underwent biennial ophthalmic examinations over 15 years. Baseline assessments began in August 2011, with biennial follow-ups through September 2025. Data were analyzed from October 2025 through December 2025.

Eye shape was classified into the following 6 categories: spheroidal, ellipsoidal, conical, nasally distorted, temporally distorted, and barrel shaped. Spheroidal and ellipsoidal types were defined as nondeformed and the others as deformed.

The primary outcomes were annual axial elongation rate, rapid elongation (≥0.10 mm/y), macular choroidal thinning (subfoveal choroidal thickness <62 µm), progression of myopic macular degeneration (MMD), incidence of posterior staphyloma, visual impairment (best-corrected visual acuity ≤20/40), and visual field defects.

Of 190 eyes from 95 participants, 152 eyes completed follow-up and were included in the analysis. Of the 152 eyes analyzed, 77 (50.7%) were from female participants, with an overall mean (SD) age of 32.3 (14.1) years. Baseline shapes included spheroidal (83 eyes [54.6%]), nasally distorted (25 [16.4%]), conical (23 [15.1%]), ellipsoidal (11 [7.2%]), temporally distorted (5 [3.3%]), and barrel shaped (5 [3.3%]). Axial elongation followed a morphology-dependent gradient, from slowest in spheroidal eyes (0.045 mm/y) to fastest in nasally distorted eyes (0.095 mm/y). After multivariable adjustment, nasally distorted eyes elongated by 0.050 mm/y (95% CI, 0.020-0.080 mm/y; P = .001) faster and had higher odds of rapid elongation (odds ratio, 5.74; 95% CI, 1.66-19.82; P = .006). Deformed eyes overall had a 7-fold higher risk of macular choroidal thinning (odds ratio, 7.24; 95% CI, 1.77-29.63; P = .006). Nasally distorted and conical eyes showed the greatest risks for both choroidal thinning and MMD progression. For visual field defects, risk was elevated in nasally distorted and conical eyes.

Findings from this prospective cohort study suggest that 3D eye shape is an important determinant of long-term outcomes in high myopia. Nasally distorted and conical phenotypes conferred the greatest risks, highlighting the potential value of baseline eye shape stratification for personalized management, risk prediction, or early intervention.

isrctn.org Identifier: ISRCTN56368396.