Myopia Prevalence, Ocular Metrics and Visual Activity in United States Optometry Students

To characterise comprehensively refractive status, ocular biometry, retinal and choroidal thickness and microvasculature, optical quality and visual activity in young adult students in the United States.

First year optometry students (N = 121, age 23.12 ± 1.64 years) underwent cycloplegic autorefraction (Grand Seiko), biometry (LenStar), optical coherence tomography and angiography (Spectralis) and ocular aberrometry (COAS HD). A visual activity questionnaire was administered. Retinal and choroidal thickness and vascular perfusion density were quantified. Ocular data and visual activity were analysed by age and race and compared across refractive error groups.

Mean spherical equivalent refraction (SER) was -2.67 ± 3.00 D, with 12% hyperopes, 18% emmetropes and 70% myopes. Mean axial length was 24.86 ± 1.26 mm. Asian participants were significantly more myopic and had longer axial lengths than Caucasian participants (p < 0.05 for both). Refraction became less myopic with increasing age (p < 0.001). Retinal and choroidal thickness varied by sector, eccentricity and refractive group (p < 0.05 for all). Superficial vascular complex perfusion density decreased with increasing axial length and more myopic SER (p < 0.01 for both). Higher-order root mean squared wavefront error was associated with axial length (p = 0.03), but not SER (p = 0.25). Reported daily near and intermediate viewing (12.43 ± 4.93 h) and outdoor time (2.2 ± 1.57 h) did not vary by refractive error or race (p > 0.05 for both).

Myopia prevalence in this cohort of optometry students was high. Refractive error and axial length were associated with retinal and choroidal structure, vascular perfusion and optical quality. Visual activity patterns were similar across refractive groups. These findings provide a comprehensive ocular profile of contemporary young adult optometry students, a population with high myopia risk, and establish a foundation for longitudinal investigations into mechanisms underlying myopia.