Abstract
PURPOSE: To quantify the amount of residual ophthalmic viscosurgicaldevice (OVD) during phacoemulsification and aspiration (PEA). METHODS: A fluorescein-stained dispersive OVD consisting of 3% hyaluronic acid (HA) and 4% chondroitin sulfate (CS) was injected into porcine eyes in volumes of 0.05, 0.1, and 0.15 mL. Subsequently, a cohesive OVD containing 1% HA was injected, and the soft shell technique (SST) was used. Porcine eyes filled with 0.4 mL of dispersive OVD alone were also evaluated. PEA was performed for 0.5, 1, 2, 3, 4, and 5 min, and the amount of dispersive OVD remaining in the eye at each time point was quantified by measuring sulfate ions contained in the CS molecules. RESULTS: Using the SST with 0.1 mL of dispersive OVD, the corneal endothelium was covered for up to 2 min of PEA, and approximately 60 μL of dispersive OVD remained. With the SST using 0.15 mL of dispersive OVD, approximately 60 μL of dispersive OVD remained 5 min after PEA, but using0.05 mL, less than 30 μL remained 0.5 min after PEA, indicating insufficient protection of the corneal endothelium. With 0.4 mL of the single agent, 60 μL of dispersive OVD remained in the eye, even after 5 min of PEA. CONCLUSION: The relationship between the injectate volume of dispersive OVD and the residual volume in the eye over the PEA time was demonstrated quantitatively. To perform SST properly, it is necessary to consider the amount of the dispersive OVD injected.