Physiology and Role of Intraocular Pressure in Contemporary Anesthesia.

Physiology and Role of Intraocular Pressure in Contemporary Anesthesia. Anesth Analg. 2017 Oct 17;: Authors: Kelly DJ, Farrell SM Abstract More than 26 million Americans suffer with cataracts, and with 3.6 million cataract extractions performed annually in the United States, it is the most common surgical procedure. The integrity of the delicate structures of the eye that mediate vision is dependent on the intraocular pressure (IOP). Yet, IOP acts to compress the vessels within the globe-akin to a Starling resistor-and is a key component that determines the ocular perfusion pressure, defined as the difference between arterial pressure and IOP. The retina is one of the most metabolically active tissues in the body, and its functional integrity is dependent on an adequate blood supply, with retinal function linearly related to the ocular perfusion pressure. Retinal cell death has been demonstrated at low perfusion pressures (below 50 mm Hg). Modern ophthalmic surgery involves globe irrigation, manipulation, and instrumentation, resulting in dynamic pressure fluxes within the eye. Marked elevations of IOP (up to 4-5 times the normal value) with consequent borderline retinal and optic disk perfusion pressures occur for prolonged periods during many ophthalmic procedures. General surgeries, including laparoscopic, spinal, and cardiac procedures, especially, with their demand for steep Trendelenburg or prolonged prone positioning and/or hy...
Source: Anesthesia and Analgesia - Category: Anesthesiology Authors: Tags: Anesth Analg Source Type: research