Correlation between quantitative OCT metrics and contrast sensitivity function in retinal artery occlusion.

AIMS To investigate the association between optical coherence tomography (OCT) biomarkers and contrast sensitivity (CS) measured by the quantitative contrast sensitivity function (qCSF) in retinal artery occlusion (RAO). METHODS This cross-sectional study included RAO patients and age-matched controls undergoing visual acuity (VA), qCSF testing and spectral-domain OCT. Only eyes with VA≥20/200 were included for reliable CS evaluation. OCT quantified retinal layer thickness, ischaemic lesion size and distance from ischaemia to the fovea. Linear regression analyses were performed. RESULTS 27 RAO eyes (17 branch RAO (BRAO), 63%) and 48 control eyes were included. All qCSF metrics were significantly reduced in RAO and central RAO compared with controls (p≤0.012). In BRAO, AULCSF and low spatial frequency CS (1-6 cycles per degree (CPD)) were significantly lower than controls (p≤0.011), whereas VA showed no significant difference. Univariable regression analysis revealed inner nuclear layer (INL) thickness (0-3 mm) was significantly associated with VA and all qCSF parameters (p<0.05). Larger ischaemic areas and closer foveal proximity correlated with worse AULCSF, contrast acuity and high spatial frequency CS (6-18 CPD; p<0.05), but not VA. Multivariable regression confirmed INL (0-3 mm) thickness was associated with VA and CS at 3 and 6 CPD (p<0.05), and foveal proximity with CS at 18 CPD (p=0.045). CONCLUSIONS qCSF shows strong correlations with INL thickness and ischaemia metrics in RAO eyes, supporting it as a valuable complementary functional measure to VA, and a meaningful clinical endpoint in RAO evaluation, particularly in foveal-sparing cases.