Authors: Steve A. Arshinoff, MD, FRCSC, Ilan Hofmann, PhD
Journal: J Cataract Refract Surg. 1998;24;814-820

Purpose: To compare the safety and efficacy of two sodium hyaluronate
viscoelastics -- I-Visc^®Plus and Healon^®GV -- in routine phacoemulsification and evaluate whether these more viscous and cohesive agents offer benefits compared to viscoelastics of standard viscosity and cohesion.

Setting: York Finch Eye Associates and York Finch General Hospital,
Toronto, Canada.

Methods: An unmasked, randomized, prospective clinical trial of 100 eyes of 100 patients having routine phacoemulisification with intraocular lens implantation was conducted comparing the safety and efficacy of I-Visc^®Plus with those of Healon^® GV. Preoperative and 6 hour, 1 and 5 days and 1 and 6 month postoperative assessments including acuity, corneal thickness, intraocular pressure, and surgeon assessment of the task-facilitating efficacy of the viscoelastics. Results were compared with those of a similar trial of I-Visc® and Healon®

Results: There were no statistically significant differences between the two treatment groups at any follow-up. The surgeon judged the two viscoelastics equivalent, although somewhat different in facilitating surgery. There was significantly less transient postoperative corneal thickening in the Healon^®GV vs I-Visc^®Plus group than in the Healon^® vs I-Visc^® group.

Conclusions: Healon^® GV and I-Visc^® Plus were safe and provided equal
outcomes based on the parameters assessed.  I-Visc^® Plus's higher zero-shear viscosity caused it to behave slightly differently than Healon^® GV during surgery. More viscous, cohesive viscoelastics may increase surgical safety.

Ultimate soft shell technique, step 1 (precapsulorrhexis).

The anterior chamber is filled 75% with viscoadaptive, then balanced salt solution is injected over the lens capsule under the mass of viscoadaptive. The anterior chamber remains pressurized because of the viscoadaptive blockading the wound.

Ultimate soft shell technique, step 2 (clearing an exit path).

Before hydrodissection is begun, the viscoadaptive in the red circle must be removed to release wound blockade.

Ultimate soft shell technique, step 3 (pre-IOL implantation).

The anterior chamber is filled with viscoadaptive injected across the capsulorrhexis. The peripheral part of the capsular bag is filled with balanced salt solution in a manner similar to hydrodissection. The IOL can then be inserted.

Author: George H.H. Beiko

Setting: Hotel Dieu Health Sciences Hospital, St. Catharines, ON Canada

Journal : Can. J. Ophthalmol.,  2003:38,No1, 52-56 (February).

Background: Healon^®5, the first viscoadaptive agent introduced in ophthalmic surgery, has been judged to be superior to Healon^® GV in protecting corneal endothelial cells. The purpose of this study was to compare the endothelial protective effects of I-Visc^® Phaco, a newer viscoadaptive agent, with those of Healon5 in cataract phacoemulsification.

Methods: A total of 96 unselected patients scheduled to undergo cataract surgery at a community-based hospital in St. Catharines, Ont., were assigned to receive I-Visc Phaco. This group was compared with 112 patients who had received Healon5 in a previous study by the author. The technique used to remove the cataract with phacoemulsification and insertion of an intraocular lens was the same in the two groups. Endothelial cell count and corneal thickness were measured preoperatively and 3 and 8 weeks postoperatively with a Konan noncontact specular microscope. One-way analysis of variance was used to analyse the data.

Results: Preoperatively there was no statistically significant difference between the Healon^®5 and I-Visc^® Phaco groups in age, eye operated, or endothelial cell count or corneal thickness. At 3 weeks there was no significant difference between the two groups in mean endothelial cell count (2110.2 [standard deviation (SD) 529.9] cells/mm2 vs. 2113.5 [SD 566.6] cells/mm2) or mean corneal thickness (586.2 µm [SD 46.73 µm] vs. 583.9 µm [SD 42.23 µm]). Similarly, there was no significant difference between the two groups in mean endothelial cell count (2113.3 [SD 496.6] cells/mm2 vs. 2145.5 [SD 573.1] cells/mm2) or mean corneal thickness (570.9 µm [SD 44.09 µm] vs. 574.4 µm [SD 40.73 µm]) at 8 weeks.

Interpretation: Results at 3 and 8 weeks postoperatively indicate that Healon^®5 and I-Visc^® Phaco protect the endothelium equally well during cataract phacoemulsification surgery.