Abstract
Purpose: :
Diabetic retinopathy is characterized by hyperperfusion in the macular area resulting in diabetic maculopathy, and hypoperfusion in the retinal periphery resulting in retinal ischemia that stimulates neovascularization. The purpose of the present study was to study the consequences of perfusion changes on retinal metabolism by assessing retinal oxygenation in patients with these complication types.
Methods: :
184 consecutive patients with diabetes mellitus (50 with T1D and 134 with T2D), referred for specialist evaluation, were subjected to a routine clinical examination, including fundus inspection and oximetry (Oxymap T1, version 2.2.1). The relative oxygen saturation in an arteriole and its adjoining venule within 1 disk diameter from the optic disk were compared between 32 patients who were diagnosed with proliferative diabetic retinopathy, 45 patients who were diagnosed with diabetic retinopathy requiring treatment, and 107 patients who were diagnosed with retinopathy not requiring treatment.
Results: :
Oxygen saturation was independent of patient age and diabetes duration. Patients with proliferative diabetic retinopathy had significantly higher oxygen saturation than patients with retinopathy not requiring treatment in retinal arterioles (98±1% vs. 96±1%, p=0.03), whereas patients with diabetic maculopathy had a significantly higher oxygen saturation than patients with retinopathy not requiring treatment in retinal venules (69±1% vs. 66±1%, p=0.01).
Conclusions: :
Increased oxygen saturation in patients with diabetic retinopathy may be the result of disturbances in retinal metabolism or retinal blood flow. An elucidation of the background for these changes may contribute to a further understanding of the pathophysiology of diabetic retinopathy.
Keywords: diabetic retinopathy