Abstract
Purpose: :
To test whether intravitreal bevacizumab injections influence retinal vessel oxygen saturation.
Methods: :
The retinal oximeter (Oxymap ehf., Reykjavik, Iceland) is based on a fundus camera. It captures two images of the same area of the fundus simultaneously; with 570 and 600nm light. Light absorbance at the two wavelengths is used to calculate relative oxygen saturation in major retinal vessels. Vessel diameter is also measured. Fifteen patients with exudative age-related macular degeneration were measured before routine 0.05mL injections of bevacizumab (Avastin®, Genentech / Roche). Three injections were given at one month intervals and the second measurement was made one month after the third injection. Additionally, five patients with either diabetic retinopathy, retinal vein occlusion or age-related macular degeneration were measured before and one week after a single injection of bevacizumab.
Conclusions: :
No changes were detected in retinal vessel oxygen saturation one month after a series of three bevacizumab injections. Presumably, the drug is no longer present at that time. An effect on retinal vessel oxygen saturation is seen one week after bevacizumab injection, suggesting a direct pharmacologic effect. This needs further study in a larger group of patients.
Keywords: age-related macular degeneration • oxygen • imaging/image analysis: clinical