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Abstract #47975 Published in IGR 13-4
Retinal oximetry in primary open-angle glaucoma
Olafsdottir OB; Hardarson SH; Gottfredsdottir MS; Harris A; Stefansson EInvestigative ophthalmology & visual science 2011; 52: 6409-6413
See also comment(s) by Makoto Araie •
PURPOSE. To determine whether retinal vessel oxygen saturation is affected in primary open-angle glaucoma (POAG) patients. METHODS. Retinal oxygen saturation in patients with POAG was measured in retinal vessels with a spectrophotometric retinal oximeter in darkness, and visual fields were obtained. Oxygen tension (Po(2)) was calculated from oxygen saturation values. Statistical analysis was performed using Pearson's correlation and Student's t-test. RESULTS. Mean oxygen saturation in venules was higher in persons with poor visual fields (68% (plus or minus) 4%, mean (plus or minus) SD) than in those with good visual fields (62% (plus or minus) 3%; P = 0.0018). The mean arteriovenous difference in oxygen saturation was lower in persons with poor visual fields (30% (plus or minus) 4%, n = 9) than in those with good visual fields (37% (plus or minus) 4%; P = 0.0003; n = 12). No correlation was found between saturation in retinal arterioles and visual field mean defect (n = 31; r = -0.16; P = 0.38). Oxygen saturation in retinal venules correlated positively with worsening visual field mean defect (r = 0.43; P = 0.015). Arteriovenous difference in oxygen saturation decreased significantly as the visual field mean defect worsened (r = -0.55; P = 0.0013). Mean Po(2) in venules was 38 (plus or minus) 3 mm Hg. It was significantly higher in persons with poor visual field fields (40 (plus or minus) 3 mm Hg) than in those with good visual fields (36 (plus or minus) 2 mm Hg; P = 0.0016). CONCLUSIONS. Deeper glaucomatous visual field defects are associated with increased oxygen saturation in venules and decreased arteriovenous difference in retinal oxygen saturation. The data suggest that oxygen metabolism is affected in the glaucomatous retina, possibly related to tissue atrophy.
O.B. Olafsdottir. Department of Ophthalmology, University of Iceland, Reykjavik.
Classification:
6.11 Bloodflow measurements (Part of: 6 Clinical examination methods)