Structure-Function Associations of Choroidal Thickness With Retinal Sensitivity in Myopia

The purpose of this study was to investigate the focal relationship between choroidal thickness and retinal sensitivity in myopic eyes.

Participants underwent swept-source optical coherence tomography (SS-OCT) imaging and microperimetry testing. Choroidal thicknesses were obtained by segmenting the SS-OCT scans using a deep-learning approach. Retinal sensitivity was measured at 33 locations using scotopic microperimetry, and corresponding focal choroidal thickness at these locations were computed. Focal structure-function associations between retinal sensitivity and choroidal thickness across 15 retinal eccentricities were evaluated, and adjusted for retinal thickness, signal strength, age, axial length, and gender.

The analysis included 280 eyes from 155 participants (mean age = 25.8 ± 3.0 years) with myopia with a mean axial length of 26.56 ± 0.99 mm and refractive error of -6.87 ± 2.05 diopters (D). Mean retinal sensitivity was 27.68 ± 1.28 decibels (dB). Mean choroid thickness was 217.85 ± 66.66 µm, with choroidal thickness in the nasal quadrant significantly thinner than in the other quadrants. Choroidal thicknesses were correlated with retinal sensitivity in 14 of 15 retinal regions, including the global eccentricity zone (r = 0.261, P < 0.001). Significant associations were similarly found with retinal thickness (r = 0.305, P < 0.001), age (r = 0.182, P < 0.05), and axial length (r = -0.402, P < 0.001). Focal structure-function models further substantiated these relationships, demonstrating a significant effect size (β = 0.78, 95% confidence interval [CI] = 0.39-1.16, P < 0.001) after adjusting for retinal thickness and other demographic factors.

Significant associations between choroidal thickness measurements and microperimetry were observed in a cross-sectional cohort of myopic eyes, suggesting a structure-function relationship with retinal sensitivity at the choroid. Further studies will be required to evaluate this in other cohorts and in progression.