Retinal vessel oxygen saturation in giant cell arteritis patients without ocular symptoms.

The aim of this study was to determine subclinical ocular ischemia related to giant cell arteritis (GCA) by means of retinal oximetry (RO) measurements.,Four test-retest RO images per eye were taken with the retinal vessel analyser (IMEDOS Systems UG, Jena). RO measurements in arterial (A-SO2) and venous (V-SO2) retinal vessels and their difference (A-V SO2) were calculated in GCA patients and compared to those of age-matched controls.,GCA biopsy and duplex sonography positive patients (n=8, 13 eyes) from the Basler Riesenzellarteriitis Kohorte study (BARK) were recruited. In controls (n=6, 10 eyes), the mean (± SD) A-SO2 and V-SO2 were measured at 93.89% (± 3.0) and at 55.60% (± 3.4), respectively. In the GCAs, a reduction in the A-SO2 to 93.37% (± 3.3) and an increase in V-SO2 to 61.13% (± 3.6) were found. The A-V SO2 difference was reduced in the GCAs to 32.24% (± 3.8) whereas in the controls the difference was 38.31% (± 2.8).,Oxygen metabolism is affected in cases with GCA. Thus, RO may provide additional data in the diagnosis of GCA, even when no ophthalmic symptoms have been reported.