Effect of Healon and Viscoat on outflow facility in human cadaver eyes

Purpose: To compare the acute effects of Healon(R) (sodium hyaluronate) and Viscoat(R) (sodium chondroitin sulfate-sodium hyaluronate) on outflow faci lity in human cadaver eyes and determine which viscoelastic agent is least likely to cause an intraocular pressure (IOP) spike after cataract surgery. Setting: The Glaucoma Research Lab, University of Toronto, Ontario, Canada. Methods: In this prospective paired study, 15 pairs of human cadaver eyes w ere used. Following the construction of a 3.0 mm scleral tunnel, 0.25 cc of Healon was injected into the anterior chamber of 1 eye and 0.25 cc of Visc oat was injected into the contralateral eye. The viscoelastic agents were r emoved from both eyes in a standardized fashion and the scleral tunnels clo sed. The eyes were then perfused at a constant IOP of 8.0 mm Hg, correspond ing to 16.0 mm Hg in vivo. Outflow facility (mu L/minute [min]/mm Hg) was r ecorded every 15 minutes for 24 hours using standard methods. Results: Outflow facility in the Viscoat-treated eyes decreased appreciably for the first 3 hours, then recovered somewhat after 12 hours; facility in the Healon-treated eyes showed less of an overall decrease. Over the 24 ho ur perfusion period, mean outflow facility was 0.037 mu L/min/mm Hg +/- 0.0 15 (SD) in the Viscoat-treated eyes and 0.060 +/- 0.012 mu L/min/mm Hg in t he Healon-treated eyes. Healon reduced outflow facility significantly less than Viscoat between 3.25 and 10.50 hours postoperatively (P < .05, 2-taile d t test). Conclusions: Healon reduced outflow facility less than Viscoat between 3.25 and 10.50 hours postoperatively. (C) 2000 ASCRS and ESCRS.