Diagnostic ability of retinal vessel diameter measurements in open-angle glaucoma

PURPOSE. To determine the diagnostic ability of retinal vessel diameter (RVD) measurements and the factors related to retinal vascular diameters in patients with open-angle glaucoma (OAG) METHODS. This retrospective observational study included 145 patients with OAG (63 with high-tension and 82 with low-tension glaucoma) and 60 healthy controls. The central retinal arteriolar equivalent (CRAE) and central retinal venular equivalent (CRVE) were measured using the IVAN software version 1.3. Receiver operating characteristic (ROC) curves were obtained for the average retinal nerve fiber layer (RNFL) thickness and RVD indices including CRAE, CRVE, and CRAE/CRVE ratio. Areas under the ROC curves (AUCs), 95% confidence intervals (CIs), and sensitivities at a fixed specificity (>90% and >80%) were calculated. Factors related to CRAE were analyzed by simple and multiple linear regression analyses. RESULTS. Among the RVD indices, the CRAE had the largest AUC for discriminating glaucomatous changes between eyes with glaucoma and those without (0.803; 95% CI, 0.742-0.855). The AUC of CRAE did not significantly differ from that of average RNFL thickness (P=0.134). However, CRAE showed lower sensitivity than average RNFL thickness at a specificity greater than 90%. Factors significantly associated with CRAE in both simple and multiple linear regression analyses were age, spherical equivalent, average RNFL thickness, presence of diabetes mellitus, and a glaucoma diagnosis (all P≤ 0.05). CONCLUSIONS. The diagnostic ability of CRAE for detecting OAG was good, which was not much worse than that of average RNFL thickness. This finding suggests the potential usefulness of RVD for glaucoma detection.