Inner retinal metabolic rate of oxygen by oxygen tension and blood flow imaging in rat

Abstract

The metabolic function of inner retinal cells relies on the availability of nutrients and oxygen that are supplied by the retinal circulation. Assessment of retinal tissue vitality and function requires knowledge of both the rate of oxygen delivery and consumption. The purpose of the current study is to report a novel technique for assessment of the inner retinal metabolic rate of oxygen (MO(2)) by combined measurements of retinal blood flow and vascular oxygen tension (PO(2)) in rat. The application of this technology has the potential to broaden knowledge of retinal oxygen dynamics and advance understanding of disease pathophysiology.

Inner Retinal Oxygen Delivery, Metabolism, and Extraction Fraction in Ins2Akita Diabetic Mice

“…15,25 Briefly, a laser line was projected onto the retina after intravenous injection of the Pd-porphine probe. Due to the angle between the excitation laser beam and imaging path, optical section phosphorescence images were acquired in which the retinal vessels were depth-resolved from the underlying choroid.…”

“…Our previously described prototype blood flow imaging system 15 was used for fluorescent microsphere imaging to assess retinal venous blood velocity and for performing FA to measure retinal arterial and venous vessel diameters. A slit-lamp biomicroscope with the standard light illumination (Carl Zeiss, Oberkochen, Germany) was equipped with a 488-nm diode laser (Melles Griot, Carlsbad, CA, USA) and an emission filter (560 ± 60 nm; Spectrotech, Inc., Saugus, MA, USA) for fluorescent microsphere imaging.…”

“…15 Typically, 20 to 30 microsphere velocity measurements were obtained in each individual vein and averaged to derive a velocity measurement per vessel (V ind ). A mean velocity (V) in each mouse was calculated based on all V ind measurements.…”

“…We have developed imaging methods to measure DO 2 and MO 2 15,16 and applied them in rats with diabetes induced by streptozotocin (STZ). 17 We found no change in either DO 2 or MO 2 at 4 and 6 weeks of diabetes.…”

Inner Retinal Oxygen Delivery and Metabolism in Streptozotocin Diabetic Rats

“…The purpose of this study was to quantitatively assess DO 2_IR and MO 2_IR in STZ rats with our previously established optical imaging method. 46,47…”