Retinal neovascularizations in proliferative diabetic retinopathy have been proposed to develop from larger retinal venules. However, angiographic evidence suggests that the new vessels may originate from both arterioles and venules, and the vitreous oxygen tension near retinal neovascularizations is similar to that of retinal arterioles. An assessment of the oxygen saturation in neovascularizations may help characterizing the vascular origin of these vessels in proliferative diabetic retinopathy.
Dual wavelength oximetry was used to study the oxygen saturation in arterioles, venules, and retinal neovascularizations in 40 eyes from 40 patients with proliferative diabetic retinopathy.
The oxygen saturation was significantly lower in retinal venules than in arterioles and neovascularizations (P < 0.0001), and after a correction for the influence of vessel diameter, there was no significant difference between the oxygen saturation in retinal arterioles and neovascularizations (P = 0.71). Age at onset and duration of diabetes mellitus contributed significantly to the variation in oxygen saturation of the venules, whereas none of the clinical background parameters contributed to the variation in oxygen saturation in arterioles and neovascularizations.
The oxygen saturation in retinal neovascularizations in proliferative diabetic retinopathy is similar to that of the arterioles. Neovascularizations may act as shunts to bypass areas of capillary occlusion.
Dual wavelength oximetry performed in 40 patients with proliferative diabetic retinopathy showed that the oxygen saturation in new vessels was similar to that in the arterioles. Neovascularizations in proliferative diabetic retinopathy may act as shunts to bypass areas of capillary occlusion.
Department of Ophthalmology, Aarhus University Hospital, Aarhus C, Denmark.
Reprint requests: Toke Bek, PhD, Department of Ophthalmology, Aarhus University Hospital, DK-8000 Aarhus C, Denmark; e-mail: email@example.com
Supported by the VELUX Foundation and the Toyota Foundation.
None of the authors has any financial/conflicting interests to disclose.