Assessment of blood flow in orbital arteries in ocular sarcoidosis

Posterior uveitis in ocular sarcoidosis is characterized by obliterative arteriolitis, so-called "microangiopathy", in sarcoidosis that may affect blood flow in ocular arteries. This study was performed to evaluate blood flow velocity in orbital arteries in patients with ocular sarcoidosis.

This study is a case-control study. Thirty-two patients with posterior uveitis diagnosed on the basis of pathological or clinical findings as having ocular sarcoidosis functioned as cases and 24 healthy volunteers as controls. Pulse rate and blood flow velocities were measured in central retinal arteries, ophthalmic arteries, or short posterior ciliary arteries by the pulsed Doppler method. Laser flaremetry was also performed. Blood flow velocities were compared in patients with sarcoidosis and controls and the correlation coefficients between flare intensity values and flow velocities were evaluated using Student's t-test.

Blood flow velocities in orbital arteries in eyes with sarcoidosis were significantly lower than those in normal eyes. The resistance index (RI) of peripheral vessels, which is calculated as (maximal velocity - minimal velocity)/maximal velocity, was significantly higher in patients with sarcoidosis. No association was found between flare intensity values and flow velocities.

Patients with ocular sarcoidosis have impairment in ocular circulation. We speculate that changes in orbital blood flow resulted from inflammatory changes in fundus vasculature.