Comparison of the effect of four viscoelastic agents on early postoperative intraocular pressure

To compare the effect of four commercially available viscoelastic agents on postoperative intraocular pressure (IOP).

Four outpatient sites.

Sixty-nine patients having routine extracapsular cataract extraction were enrolled in the study; 54 were available for a 3 month follow-up examination. The four viscoelastic agents were Amvisc, Amvisc Plus, Healon, and Viscoat. Intraocular pressure was measured preoperatively and at 2, 3, 4, 5, 6, 8, 10, 12, and 24 hours and 3 months postoperatively. Pachymetry and endothelial cell counts were performed preoperatively and 3 months postoperatively.

Mean postoperative IOP and IOP changes from baseline did not differ among the four treatment groups at any time. However, when mean maximal IOP was compared, the Healon group demonstrated the highest IOP increases (P = .0033). There was also a significant difference (P = .0015) among the treatment groups in the mean maximum postoperative change from baseline; the Healon group exhibited the largest mean change in IOP. At 3 months postoperatively, IOP values and pachymetry were normal for all treatment groups and were not statistically different among groups, indicating the four agents provided similar degree of endothelial protection and IOP stability.

These results suggest that IOP increases occur in varying degrees and at varying times in the early postoperative period after cataract surgery using a viscoelastic agent.