A COMPARISON OF RETINAL AND CHOROIDAL HEMODYNAMICS IN PATIENTS WITH PRIMARY OPEN-ANGLE GLAUCOMA AND NORMAL-PRESSURE GLAUCOMA

PURPOSE: To quantify, compare, and assess differences between retinal and choroidal hemodynamics in normal control subjects and patients wit h ocular hypertension, primary open-angle glaucoma, and normal-pressur e glaucoma. METHODS: Video fluorescein angiograms were made in 20 norm al subjects, 11 patients with ocular hypertension, 45 patients with pr imary open-angle glaucoma, and 43 patients with normal-pressure glauco ma. Choroidal dye build-up curves were analyzed using an exponential m odel. The model time constant tau reflected the local blood refreshmen t time, the time needed to replace the blood volume in a tissue volume . Retinal arteriovenous passage time was estimated from the time lapse between retinal arterial and venous dye curves. RESULTS: The retinal arteriovenous passage time was longer in patients with primary open-an gle glaucoma compared with normal subjects and patients with normal-pr essure glaucoma; the average arteriovenous passage times (+/-SEM) in n ormal subjects and in patients with ocular hypertension, primary open- angle glaucoma, and normal-pressure glaucoma were, respectively, 2.44 +/- 0.19, 2.90 +/- 0.37, 3.02 +/- 0.17, and 2.55 +/- 0.15 seconds. Cho roidal tau was longest in the normal-pressure glaucoma group but not a s long in the primary open-angle glaucoma group; tau values in normal subjects and patients with ocular hypertension, primary open-angle gla ucoma, and normal pressure glaucoma were, respectively, 4.6 +/- 0.29, 5.6 +/- 0.69, 6.2 +/- 0.39, and 7.1 +/- 0.33 seconds. CONCLUSIONS: Whe reas choroidal circulation is especially slower in patients with norma l-pressure glaucoma, retinal circulation is delayed in patients with p rimary open-angle glaucoma. The choroidal and retinal vascular systems behave differently in primary open-angle and normal-pressure glaucoma , which may be important in the management of glaucoma.