Abstract
Purpose :
Giant cell arteritis (GCA) is a potentially sight threatening disease. Although it is associated with polymyalgia rheumatica (PMR), visual loss is not common in PMR. We performed an observational, cross-sectional study to investigate if retinal oxygen saturation and retinal vessel calibers in GCA- and PMR differed similarly from controls.
Methods :
Retinal oximetry was performed with Oxymap T1 (Oxymap, Reykjavik, Iceland) on 20 GCA-patients (n=38 eyes), 18 PMR-patients (n=33 eyes) and 12 controls (n=20 eyes) at Odense University Hospital, Odense, Denmark. Age < 50 years, poor image quality (<6.0) and eyes with neurodegenerative-, severe retinal-, or optic nerve disease were excluded. Images were analyzed with Oxymap Analyzer software 2.5.0 (Oxymap, Reykjavik, Iceland).
Cluster Robust Standard Error was used in a linear mixed model regression analysis adjusted for age and sex, to determine the principal outcomes consisting of retinal arteriolar- and venular oxygen saturation, retinal arterio-venular difference and retinal vessel diameters.
Results :
Median age (interquartile range) for GCA, PMR and controls were 69.0 years (66.5-76.5), 69.0 years (67.0-72.0) and 75.5 years (71.5-81.0), respectively. According to the age- and sex-adjusted linear mixed model regression, the retinal arteriolar diameters were wider for GCA as compared to controls and PMR as compared to controls (13.4 pixels vs. 12.4 pixels, p=0.02 and 13.5 pixels vs. 12.4 pixels, p=0.04, respectively). There were no differences with respect to retinal venular diameters (17.4 pixels vs. 16.7 pixels, p=0.1 and 17.3 pixels vs. 16.7 pixels, p=0.2, respectively), retinal arteriolar oxygen saturation (92.9% vs. 91.4%, p=0.2, and 93.4% vs. 91.4%, p=0.1, respectively), retinal venular oxygen saturation (53.8% vs. 55.0%, p=0.7, and 52.8% vs. 55.0%, p=0.5, respectively) or retinal arterio-venular difference (39.1% vs. 36.3%, p=0.3, and 40.6% vs. 36.3%, p=0.1, respectively).
Conclusions :
Compared to controls, patients with GCA and PMR both had wider retinal arterioles but unaffected retinal venular diameter and retinal metabolism. While this indicates a similar effect on the retinal vascular structure, prospective studies are needed to determine, if these parameters can be used to predict the clinical outcome.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.