New Frontiers in Noninvasive Analysis of Retinal Wall-to-Lumen Ratio by Retinal Vessel Wall Analysis

PURPOSE: To compare measurement of wall-to-lumen ratio (WLR) by means of high-resolution adaptive optics imaging (AO) with intuitive to use retinal vessel wall (VW) analysis (VWA). Moreover, to validate the techniques by comparing WLR of healthy young (HY) with healthy older patients. METHODS: Ten retinal VW images of 13 HY (24 ± 2 years) and 16 healthy older (60 ± 8 years) were obtained with AO and VWA. The average of five measurements of VW, retinal vessel lumen and WLR of a single vessel from AO and VWA were calculated and compared. RESULTS: WLR of AO and VWA images showed high correlations, r = 0.75, t(27) = 5.98, P < .001, but differed systematically (WLR: VWA, 40 ± 7% and AO, 35 ± 9%; P < .001). Comparable patterns were found for VW and vessel lumen. HY showed significantly lower WLR (AO, 31 ± 8% and VWA, 36 ± 8%) compared with healthy older (AO, 39 ± 9% [P = .012]; VWA, 42 ± 5% [P = .013]). CONCLUSIONS: Assessment of WLR by VWA showed a good correlation with laborious analysis of the microstructure by high-resolution AO. Measurement of WLR in different age groups indicated good validity. Deviations in VW, vessel lumen, and WLR between AO and VWA can be explained by systematic differences in image scale and resolution. Future studies are needed to investigate the clinical relevance of microvascular WLR assessment by retinal VWA and its prognostic value. TRANSLATIONAL RELEVANCE: Additional assessment of retinal WLR by use of digital VWA to evaluate microstructural remodeling may prove to be a valuable extension to the current use of retinal vessel diameters as biomarkers of cardiovascular risk.