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Abstract #6409 Published in IGR 3-2
Optic nerve blood flow is diminished in eyes of primary open-angle glaucoma suspects
Piltz-Seymour JR; Grunwald JE; Hariprasad SM; Dupont JAmerican Journal of Ophthalmology 2001; 132: 63-69
PURPOSE: To evaluate optic nerve blood flow in primary open-angle glaucoma (POAG) suspect eyes with normal automated visual fields, in an attempt to elucidate how early in the glaucomatous disease process changes in optic nerve blood flow become apparent. METHODS: Twenty-one eyes (21 patients) suspected of having POAG were studied prospectively and compared with a previously reported cohort of 22 eyes (22 patients_ with POAG and 15 eyes (15 subjects) of age-matched controls. POAG suspect eyes had untreated intraocular pressure (IOP) greater than 21 mmHg and normal visual fields using Humphrey program 24-4 or 30-2 with a full-threshold strategy. Laser Doppler flowmetry was used to measure optic nerve head blood velocity, volume, and flow at four quadrants in the optic nerve, cup, and foveola of one eye of each patient. The mean flow from the superotemporal rim, inferotemporal rim, and cup was calculated (Flow3) and identified as the main outcome measure. Measurements from POAG suspect eyes were compared with corresponding measurements from controls and eyes with POAG; Student's t test was used with a Bonferroni correct p value of 0.025 to account for comparisons of POAG suspects both to controls and to eyes with POAG. RESULTS: Compared with controls, Flow3 was 24% lower in POAG suspect eyes (p < 0.0003). In POAG suspect eyes, flow was 16% lower in the superotemporal rim (p < 0.007), 35% lower in the cup (p < 0.007), and 22% lower in the inferotemporal neuroretinal rim (p < 0.029) compared with controls. No significant difference between POAG suspect and control eyes was seen in the inferonasal rim, superonasal rim, or foveola. No significant difference was detected at any location between POAG suspect eyes and eyes with POAG. CONCLUSIONS: Laser Doppler flowmetry detected circulatory abnormalities in POAG suspects who did not have any manifest visual field defect. Decreases in flow in glaucoma suspects were similar in magnitude to those of subjects with POAG. These data suggest that impaired optic nerve blood flow develops early in the glaucomatous process and does not develop solely as a result of glaucoma damage.
Dr J.R. Piltz-Seymour, Department of Ophthalmology, Scheie Eye Institute, University of Pennsylvania Health systems, 51 N 39th Street, Philadelphia, PA 19104, USA. piltz@mail.med.upenn.edu
Classification:
6.11 Bloodflow measurements (Part of: 6 Clinical examination methods)
