Subclinical Microvascular Deficits as a Promising Biomarker for Functional Impairment in Non-Pathological High...

Myopia causes retinal structural and microvascular alterations, impairing visual function. This study examined macular vessel density using optical coherence tomography angiography (OCTA) and its relationship with macular light sensitivity (MLS) in myopic eyes, particularly in extreme myopia, to determine if vessel density can serve as an early marker for detection and monitoring of functional changes.

A cross-sectional study included 283 myopic eyes (age 18-60 years) grouped into low/moderate (LM&MM: -0.50D ≥ SE > -6.00D), high (HM: SE -6.00D to -10.00D), and extremely high myopia (EHM: SE ≤-10.00D). All eyes underwent OCT and OCTA (6 × 6mm macular scans) to measure retinal and ganglion cell complex thicknesses and superficial (SVD) and deep vessel densities (DVD), as well as MP-1 microperimetry to assess MLS in central and parafoveal regions. Key outcome parameters were SVD, DVD, GCCT, and MLS.

Macular SVD, DVD, and MLS decreased with increasing myopia severity (p < 0.01). Extremely myopic eyes had significantly lower SVD (47.37 vs 49.57), DVD (52.33 vs 55.55), and MLS (18.54 dB vs 19.24 dB) than low/moderate myopia eyes (all p < 0.01). These reductions were significant in most parafoveal quadrants, sparing the central foveal area (for vessel density) and nasal quadrant (for sensitivity). DVD correlated positively with MLS, especially in EHM and in the overall cohort, whereas SVD showed more limited correlations, primarily in the superior and temporal sectors. Multivariate regression identified DVD as an independent predictor of MLS, alongside SE and axial length.

Macular vessel density, particularly in the deep vascular plexus, declines with greater myopia and correlates with diminished macular function. OCTA-derived macular vessel density could be a promising biomarker candidate for early detection and monitoring of retinal functional impairment in myopic eyes.