Retrobulbar hemodynamics in normal tension glaucoma compared to anterior ischemic optic neuropathy

Abstract

Abstract Purpose: To compare flow velocities of the retrobulbar vessels in chronic vascular neuropathy in normal tension glaucoma (NTG) to those of acute circulatory disorder of anterior ischemic neuropathy (AION). Methods: Fifty‐two patients with NTG (mean age: 66 ± 8 ys) and 50 patients with AION (mean age: 68 ± 10 ys) were included in the study. Blood flow velocities (peak systolic velocity PSV and end–diastolic velocity EDV) and resistive indices of the ophthalmic artery (OA), central retinal artery (CRA) and nasal and temporal posterior ciliary arteries were measured by means of colour Doppler imaging (CDI). Results: No differences were detected for heart rate, diastolic arterial pressure and IOP between the two groups. In AION patients systolic arterial blood pressure was significantly higher compared to the NTG group (148 ± 26 mm Hg vs. 131 ± 18 mmHg, p = 0.0004). CDI revealed significant differences of the resistive index of the OA (RI AION: 0.80 ± 0.06; NTG: 0.76 ± 0.07). In AION, PSV of CRA was significantly lower compared to NTG (AION: 7.2 ± 1.9 cm/s; NTG 8.0 ± 1.6 cm/s). Conclusions: The chronic vascular deficiency in NTG seems to be similar to that of the acute circulatory breakdown in AION. In both vascular disorders of the optic nerve only small differences of flow velocities may be detected by CDI.