Retinal oxgen metabolism under visual stimulation of neuronal activity in health and disease

• Published in: Acta ophthalmologica (Oxford, England) Vol. 92; no. s253
• Main Authors: HAMMER, M, RAMM, L, PETERS, S, JENTSCH, S, SAUER, L, AUGSTEN, R
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.09.2014; Wiley Subscription Services, Inc
• Subjects: Ophthalmology
• ISSN: 1755-375X; 1755-3768
• DOI: 10.1111/j.1755-3768.2014.3718.x

Goal: To measure retinal vessel oxygen saturation in rest and under stimulation of neuronal activity by flicker light as well as vascular dilation upon flicker. Methods: 18 patients with non‐proliferative diabetic retinopathy (mean age: 62.2±8.3 years), 41 patients with primary open angle glaucoma (64.0+12.8 years) and 40 control subjects (63.6+14 years) were investigated. Vessel diameters (central retinal arterial and venous equivalents – CRAE and CRVE) and oxygen saturation (SO2, dual – wavelength optical oximetry) were determined before and during luminance flicker stimulation (12.5 Hz, modulation depth: 1:20) for 90 s. Results: Flicker light increased CRAE, CRVE, and venous SO2 by 1.42%±3.72%, 2.80%*±2.70%, and 2.03%*±2.43% in diabetic patients as well as 4.98%*±6.23%, 8.94%*±5.26%, and 4.20%*±3.71% in the controls (*: p<0.05). This increase was significantly higher in the controls vs. patients for all parameters (t‐test, p<0.05. In glaucoma, the increase of CRVE (3.7+3.3%, p=0.039) and venous SO2 (2.482+2.453%, p=0.029) was significantly lower than in controls. Conclusions: Combining SO2 and vessel diameter measurements with visual stimulation reveals pathologic alterations in retinal oxygen supply or consumption. Commercial interest