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Abstract #5287 Published in IGR 1-2
Progress in measurement of ocular blood flow and relevance to our understanding of glaucoma and age-related macular degeneration
Harris A; Chung HS; Ciulla TA; Kagemann LProgress in Retinal and Eye Research 1999; 18: 669-687
New technologies have facilitated the study of the ocular circulation. These modalities and analysis techniques facilitate very precise and comprehensive study of retinal choroidal, and retrobulbar circulations. These techniques include: 1. Vessel caliber assessment; 2. Scanning laser ophthalmoscopic fluorescein angiography; and indocyanine green angiography to image and evaluate the retinal circulation and choroidal circulation, respectively; 3. Laser Doppler flowmetry and confocal scanning laser Doppler flowmetry to measure blood flow in the optic nerve head and retinal capillary beds; 4. Ocular pulse measurement; and 5. Color Doppler imaging to measure blood flow velocities in the central retinal artery, the ciliary arteries and the ophthalmic artery. These technique have greatly enhanced the ability to quantify ocular perfusion defects in many disorders, including glaucoma and age-related macular degeneration, two of the most prevalent causes of blindness in the industrialized world. Recently it has become clear, in animal models of glaucoma, that retinal ganglion cells die via apoptosis. The Factors that initiate apoptosis in these cells remain obscure, but ischemia may play a central role. Patients with either primary open-angle glaucoma or normal-tension glaucoma experience various ocular blood flow deficits. With regard to age-related macular degeneration, the etiology remains unknown although some theories include primary retinal pigment epithelial senescence, genetic defects such as those found in the ABCR gene which also defective in Stargardt's disease and ocular perfusion abnormalities. As the choriocapillaris supplies the metabolic needs of the retinal pigment epithelium and the outer retina, perfusion defect in the choriocapillaris could account for some of the physiologic and pathologic changes in AMD. Vascular defects have been identified in both nonexudative and exudative AMD patients using new technologies. This paper is a comprehensive update describing modalities available for the measurement of all new ocular blood flow in human and the clinical use.
A. Harris, Glaucoma Research Diagnostic Center, Department of Ophthalmology, Indiana University, Indianapolis, IN 46202; United States
Classification:
6.11 Bloodflow measurements (Part of: 6 Clinical examination methods)
