Influence of viscoelastic substances used in cataract surgery on corneal metabolism and endothelial morphology: Comparison of Healon and Viscoat

Purpose: To evaluate the influence of cohesive and dispersive ophthalmic vi scosurgical devices (OVDs) on endothelial morphology and corneal metabolism during cataract surgery. Setting., Department of Ophthalmology, University of Vienna Medical School, Vienna, Austria. Methods. In this prospective randomized blind study, 50 eyes of 43 patients were randomized into 2 groups before surgery. Phacoemulsification with imp lantation of a posterior chamber intraocular lens was performed in all pati ents. In half the patients, sodium hyaluronate 1% (Healon (R)) was used as the OVID and in the other half, sodium hyaluronate 3%-chondroitin sulfate 4 % (Viscoat (R)). Corneal metabolism was evaluated by fluorophotometric meas urement of corneal autofluorescence. The corneal fluorescence values were c orrected for interference by fluorescence of the ocular lens. Specular micr oscopy (Noncon Robo SP800, Canon) was used to evaluate the endothelial cell density, coefficient of variation, and percentage of hexagonal cells. Exam inations were performed preoperatively and 3 days, 1 and 4 weeks, and 3 mon ths postoperatively. Results: There were no significant changes between preoperative and postope rative endothelial cell density measurements in either group (P = .1717). T he percentage of hexagonal cells was similar (P = .3489); however, there wa s a slightly increasing tendency toward polymorphism in both groups, Cornea l autofluorescence decreased 3 days after surgery, increased after 1 week, and decreased again subsequently in both groups. There was no significant d ifference in the influence on corneal metabolism between the 2 OVDs (P = .9 899). Conclusions: There was no significant difference between Healon and Viscoat , Thus, this study did not confirm an advantage of either for endothelial p rotection of healthy comeas. (C) 2001 ASCRS and ESCRS.