The shape a myopic eye takes matters more than how long it gets

Design

15-year two-time-point 3D orbital MRI cohort substudy nested within the Zhongshan High Myopia Cohort, imaged 2011 and rescanned 2025

Population

30 participants (60 eyes) with bilateral high myopia, spherical equivalent -6.00 D or worse, mean age 37.3 years

Primary outcome

distribution of five globe remodelling patterns and their association with myopic macular degeneration, traction maculopathy, posterior staphyloma and visual function

Effect

at similar axial elongation, focal deformation vs not: MMD progression 91.7% (74.2-97.7) vs 58.8% (36.0-78.4), P=.02; staphyloma 91.7% vs 17.6% (6.2-41.0), P<.001; MTM 58.3% vs 11.8%, P=.003

This substudy of the Zhongshan High Myopia Cohort did something rare: it rescanned the same highly myopic eyes 15 years apart on orbital 3D MRI. Thirty participants, 60 eyes, all with spherical equivalent of -6.00 D or worse, imaged in 2011 and again in 2025, with globes classified into six shape categories and change classified into five remodelling patterns.

Thirty-five per cent of eyes were quiescent. The rest expanded proportionally (20.0%), developed new focal deformation (23.3%), progressed an existing one (10.0%), or changed shape category (11.7%). No deformed eye ever reverted to spheroidal. Age at baseline strongly patterned this: 83.3% of eyes in people under 20 expanded proportionally, while 54.2% of those aged 40 and over showed focal progression or shape transition.

The clinically important comparison controls for elongation. At similar axial growth, eyes that developed focal deformation had far more myopic macular degeneration progression (91.7%, 95% CI 74.2 to 97.7, versus 58.8%, 95% CI 36.0 to 78.4; P = 0.02), far more incident or progressive posterior staphyloma (91.7% versus 17.6%, 95% CI 6.2 to 41.0; P < 0.001), and more myopic traction maculopathy (58.3% versus 11.8%; P = 0.003). In other words, two eyes that elongated by the same amount had very different fates depending on whether the elongation was uniform or focal — and axial length alone cannot distinguish them. Sixty eyes and two time points is a small study built on a rare dataset; the authors call this a candidate framework pending prospective validation, and that is the right reading.

• Do not treat axial length as a complete measure of risk in high myopia — the pattern of elongation carried the outcomes
• Expect proportional expansion in younger patients and focal deformation in those over 40
• Take posterior contour on imaging seriously as a prognostic feature, not only as a description
• Focal deformation, once present, did not reverse in any eye over 15 years
• Thirty participants and two time points — a framework worth watching, not a surveillance protocol

The statistics, in plain English

The outcome differences are large and the P values small, but they come from 60 eyes split into five patterns, so several groups contain fewer than ten eyes and the confidence intervals are correspondingly wide (91.7% carries an interval of 74.2 to 97.7). Two time points 15 years apart tell you where an eye started and finished but nothing about the path between, so a pattern labelled quiescent may have changed and returned. Participants were randomly drawn from a larger imaged cohort, which protects against selection within that cohort but not against how the cohort itself was assembled.

Read the rest in the app

You have read your two free briefings this month. The app carries all 27 specialties, every morning, free — and this finding is waiting in it.

Get Daily Doctor — free

Scan to keep reading on your phone. No account needed to start.