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Abstract #8441 Published in IGR 5-1
Blood flow per unit retinal nerve fibre tissue volume is lower in the human inferior retina
Harris A; Ishii Y; Chung HS; Jonescu-Cuypers CP; McCranor LJ; Kagemann L; Garzozi HJBritish Journal of Ophthalmology 2003; 87: 184-188
AIM: To determine if perfusion per unit tissue volume of retinal nerve fiber layer and optic nerve head in the inferior sector is lower than in the superior sector. METHODS: Heidelberg retinal tomogram (HRT) for topographic measurement of optic nerve head and retinal nerve fiber layer and Heidelberg retinal flowmeter (HRF) for retinal blood flow were performed on 19 normal healthy subjects. Measurements from the superior and inferior sectors were compared. The perfusion/nerve fiber ratio (PNR); the blood flow per unit retinal nerve fiber tissue volume, was calculated in each sector with a formula; HRF flow measurements divided by HRT measurements. RESULTS: Retinal nerve fiber layer thickness in the inferior retina was significantly higher than in the superior retina (p < 0.05). However, there were no differences in retinal blood flow between the superior and inferior retinal sectors. The PNR in the inferior sector were significantly lower than in the superior sector (p = 0.047 for HRF mean flow/rim volume and p = 0.0282 for HRF 75th percentile flow/rim volume). CONCLUSIONS: The inferior sector of retinal nerve fiber layer and optic nerve head may have lower blood flow per unit nerve tissue volume compared to the superior sector. This result suggests that the inferior sector is more vulnerable to elevated intraocular pressure and ischemic insults in glaucomatous optic neuropathy.
Dr. A. Harris, Department of Ophthalmology, Indiana University School of Medicine, Indianapolis, IN, USA. alharris@indiana.edu
Classification:
6.11 Bloodflow measurements (Part of: 6 Clinical examination methods)
