A COMPARISON OF HEALON AND AMVISC ON THE EARLY POSTOPERATIVE PRESSUREAFTER EXTRACAPSULAR CATARACT-EXTRACTION WITH IMPLANTATION OF POSTERIOR CHAMBER LENS

Two viscoelastic agents, Healon and Amvisc, both hyaluronic acids, wer e evaluated in two prospective, randomized and masked studies in order to compare the effect of the viscoelastics and timolol (Blocadren) on the early postoperative intraocular pressure (IOP) after planned extr acapsular cataract extraction with implantation of a posterior chamber lens. The study protocols were similar, especially with regard to the sample size, pre-, per- and postoperative management and sampling. Th e IOP was measured preoperatively, 3-6 and 24 h postoperatively. The t esting of Amvisc revealed that aspiration or non-aspiration of Amvisc at the end of surgery was of little importance for the IOP, and that t imolol significantly reduced the IOP 3-6 h postoperatively in the orde r of about 8 mmHg. The postoperative IOP was lower for Amvisc than for Healon only when the viscoelastic material was aspirated and topical timolol was administered. In all the other groups there were no signif icant differences between the viscoelastics as far as the postoperativ e pressure was concerned. Multiple regression revealed a marked pressu re reducing effect of timolol 3-6 h postoperatively in both groups, bu t no effect was observed 24 h postoperatively. The two viscoelastic ag ents showed minor effect on the IOP both 3-6 and 24 h postoperatively.