HEMODYNAMIC-ALTERATIONS IN THE ACUTE RETINAL NECROSIS SYNDROME

Background. Clinical and histopathologic observations suggest a role f or ischemia in the pathogenesis of the acute retinal necrosis (ARN) sy ndrome. Disruption of blood flow appears to occur at some level in the retina or choroid and may account for some of the major features of t he syndrome. Methods: To investigate these potential circulatory chang es, color Doppler imaging (CDI) was used to quantitate blood flow velo cities and vascular resistance in the central retinal, ophthalmic, and short posterior ciliary arteries in ten consecutive patients with uni lateral ARN syndrome. Data were analyzed with a paired Student's t tes t. The unaffected fellow eyes served as controls. Results: Blood flow velocities within the central retinal artery were significantly reduce d in eyes with ARN syndrome compared with control eyes. In affected ey es, there was a mean reduction of 55%, 60%, and 72% in peak systolic, average, and end-diastolic velocities, respectively (P <0.01). The cal culated vascular resistance of the central retinal artery showed an up ward trend, but the data fell short of statistical significance. Blood flow velocities from the ophthalmic and short posterior ciliary arter ies were not significantly different compared with controls. Conclusio ns: This study demonstrates marked circulatory changes in the central retinal artery of eyes involved with the ARN syndrome. Although the ex act mechanism and clinical significance are yet to be determined, the data support the presence of retinal arterial hemodynamic compromise i n this condition.