Does the Lens Continue to Counteract Axial Elongation in Adults with High Myopia?

To investigate the longitudinal lens thickness (LT) and lens power (LP) change patterns and associated factors in high myopes.

Prospective cohort study.

Chinese individuals with high myopia (spherical power ≤ -6.00 diopters [D]) with a baseline age from 7 to 50 years.

Patients with high myopia from the Zhongshan Ophthalmic Center-Brien Holden Vision Institute High Myopia cohort have been followed up every other year for 8 years. Participants with ≥2 visits were included. At each visit, ocular biometrics, including LT, were measured with Lenstar LS900 (Haag-Streit AG) or IOL Master 500 (Carl Zeiss Meditec). Lens power was calculated with the Bennett formula. Longitudinal changes in LT and LP in individuals at different ages and axial length elongation rates (slow/rapid) were quantified.

Changes in LT and LP.

A total of 708 participants (median age [interquartile range]: 16.84 years [13.52-23.11]; 53.1% female) were included. The lens consistently thickened with age (β = 0.027 mm/year; 95% confidence interval [CI], 0.026-0.028; P < 0.001). The lens lost power from 7 to 18 years, after which LP stabilized for slow progressors (β = 0.003 D/year; 95% CI, -0.026 to 0.033) but continued to lose power in rapid progressors (β = -0.042 D/year; 95% CI, -0.062 to -0.021; P < 0.001). In adults, LP loss was significantly associated with axial elongation (β = -0.469 D; 95% CI, -0.557 to -0.381; P < 0.001), but not with age. Mediation analysis indicated that axial elongation, but not age, had a direct effect on LP loss.

In high myopes, LT consistently increased with age. The lens continued to lose power to counteract axial elongation in adults with high myopia, with rapid axial elongation.

The author has no/the authors have no proprietary or commercial interest in any materials discussed in this article.