Purpose: To investigate the 10-year changes in visual function and incidence of visual impairment (VI) in highly myopic eyes.
Methods: This longitudinal study enrolled highly myopic individuals who were followed up for 10 years. All participants underwent detailed ophthalmic examinations at baseline and follow-up visits. Best-corrected visual acuity (BCVA) was measured using Early Treatment of Diabetic Retinopathy Study protocol, and visual field (VF) was assessed with standard automatic perimetry.
Results: A total of 568 highly myopic eyes (284 participants) were included, with mean baseline age of 22.49 ± 13.07 years, spherical equivalent refraction (SER) of -9.72 ± 3.02 D, and axial length of 27.39 ± 1.53 mm. Over 10 years, the mean BCVA loss was -0.06 logMAR (95% confidence internal [CI], 0.05-0.07). The mean change rates in mean deviation (MD) and pattern standard deviation over time were -0.07 dB/y (95% CI, -0.08 to -0.06) and 0.036 dB/y (95% CI, 0.028 to 0.044), respectively. The 10-year incidence of monocular moderate and severe VI (MSVI), per World Health Organization (WHO) and US criteria, was 3.52% (95% CI, 2.16%-5.39%) and 6.35% (95% CI, 4.46%-8.72%). Higher MSVI incidence, defined by WHO and US criteria, was associated with more myopic SER and lower baseline MD. Additionally, higher US-defined MSVI incidence was correlated with worse baseline BCVA.
Conclusions: In a highly myopic population, both BCVA and VF deteriorated over time, with increasing MSVI incidence. Raising public awareness of vision risks linked to high myopia and implementing strategies to reduce the burden in high-risk individuals are essential.