Corneal endothelial cell protection during phacoemulsification

PURPOSE: To compare the efficacy of low- and high-molecular-weight sodium hyaluronate in protecting corneal endothelial cells during phacoemulsification. SETTING: Miyata Eye Hospital, Miyakonojo, Miyazaki, Japan. METHODS: One hundred forty-nine eyes of 136 cataract patients were randomly assigned to have cataract surgery using sodium hyaluronate 1% with a low molecular weight (0.6 to 1.2 million d, Opegan) or sodium hyaluronate 1% with a high molecular weight (4 million d, Healon) during phacoemulsification. Each group was divided into 2 subgroups depending on the amount of ultrasound (% min) used during phacoemulsification, which was defined as the mean phacoemulsification energy (%) multiplied by phacoemulsification time (minutes). Corneal endothelial cell density was examined preoperatively and 3 months after surgery. The rate of cell loss was compared between the subgroups in the Opegan group and the Healon group. RESULTS: In the subgroups with ultrasound of 50% min or less, the mean rate of endothelial cell loss 3 months after surgery was 3.2% +/- 4.1% (SD) in the Opegan group and 5.9% +/- 5.3% in the Healon group (P =.0214). In the subgroups with ultrasound over 50% min, the mean rate of endothelial cell loss 3 months after surgery was 7.5% +/- 10.6% in the Opegan group and 14.8 +/- 9.0% in the Healon group (P =.0029). CONCLUSIONS: The results suggest that Opegan is more effective than Healon in protecting corneal endothelial cells during phacoemulsification regardless of the amount of ultrasound energy used.