Structure-Function Associations between Contrast Sensitivity (CS) and Vascular Metrics on Wide Field Swept Source Optical Coherence Tomography Angiography (WF SS OCTA) across stages of Diabetic Retinopathy

Abstract

Purpose : To investigate structure-function associations between CS and vascular metrics on WF SS OCTA across stages of non proliferative diabetic retinopathy (NPDR) and proliferative diabetic retinopathy (PDR), in the absence of diabetic macular edema (DME).

Methods : This prospective observational study included 95 eyes of 78 patients, including 20 mild NPDR eyes, 12 moderate/severe NPDR, 22 PDR, 14 diabetic eyes without DR (DMnoDR), and 27 control eyes. LogMAR Visual Acuity (VA) was measured. CS was measured with the active learning quantitative CS function (qCSF) Manifold Contrast Vision Meter (Adaptive Sensory Technology) and outcomes included Area under the Log CSF (AULCSF) and contrast sensitivity (CS) thresholds at 1-18 cycles per degree (cpd). All eyes were imaged using WF SS OCTA (Plex Elite 9000, Carl Zeiss Meditec). The ARI Network (Zeiss Portal v5.4) delivered vascular metrics, including vessel density (VD) and vessel skeletonized density (VSD) in the superficial and deep capillary plexus (SCP, DCP) on 6x6 mm images. Mixed-effects multivariate regression models were used to evaluate associations between CS functional outcomes and WF SS OCTA structural outcomes across DR stages.

Results : Controlling for age and lens status in the whole cohort, VD in the SCP was significantly associated with LogMAR VA (β= -0.02, P<0.001), AULCSF (β= 0.03, P<0.001), and CS thresholds at 1cpd (β= 0.02, P=0.004), 1.5cpd (β= 0.02, P=0.005), 3cpd (β= 0.03, P=0.009), 6cpd (β= 0.04, P=0.002), 12cpd (β= 0.04, P= 0.002) and 18cpd (β= 0.01, P= 0.044).VSD in the SCP was associated with LogMAR (β= -1.19, P= 0.010), AULCSF (β= 1.18, P= 0.010), and CS at 1cpd (β= 1.00, P=0.008), 1.5cpd (β= 0.91, P=0.016), 3cpd (β= 0.89, P= 0.039), 6cpd (β= 1.5, P= 0.011) and 12cpd (β= 1.44, P= 0.008); VD in the DCP was associated with LogMAR (β= -0.01, P=0.008), AULCSF (β= 0.01, P= 0.066) and 12cpd (β=0.18, P=0.013) and VSD in the DCP with LogMAR (β= -0.49, P=0.013), AULCSF (β= 0.47, P= 0.099), 12cpd (β=0.82, P=0.021).

Conclusions : We present novel structure-function associations across stages of DR without DME, leveraging WF SS OCTA imaging and CS metrics. The progressive decline in the OCTA vascular metrics across DR stages seems to be associated with equally large changes in contrast sensitivity metrics as in VA.

This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.