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October 1970

Studies in Uveal PhysiologyII. Clinical Studies of the Anterior Chamber Clearance of Isotopic Tracers

Author Affiliations

Hartford, Conn; Bethesda, Md
From the Division of Ophthalmology, University of Connecticut Health Center, Hartford, Conn (Dr. O'Rourke), and the Pharmacology Section, National Eye Institute, Bethesda, Md (Dr. Macri).

Arch Ophthalmol. 1970;84(4):415-420. doi:10.1001/archopht.1970.00990040417003

The clearance of various isotopic tracers was measured by external monitoring of iodine 125 radioactivity. A method of "wet wall" microinjection and mixing, previously described, was employed in 81 studies made. The clearance of each tracer occurred as a monoexponential function at rates appropriate to differences in molecular diameter. Serum albumin disappeared at a 1.3%/ min rate and was inhibited 55.6% following intravenous infusion of acetazolamide. Washout of iodoantipyrine was equivalent to a capillary blood flow of 6.84 cc/100 gm of uveal tissue per minute. Since this clearance was inhibited 45.9% in association with active uveal inflammation, it is speculated that inflammation may reduce the diffusion of the tracer and raise tissue specific gravity without necessarily reducing blood flow. The possibility that oxygen diffusion is similarly reduced in uveitis is considered.