A simple method to shorten the unfolding time of prehydrated hydrophobic intraocular lens

Abstract

Objective: To evaluate the effect of warm ophthalmic viscosurgical devices (OVDs) on the unfolding time of prehydrated hydrophobic acrylic intraocular lenses (IOLs). Design: Experimental study and human trial. Participants: Three foldable hydrophobic acrylic IOLs (en Vista MX60, AcrySof SN60AT, and Tecnis 1 ZCB00). Methods: The unfolding times of 3 kinds of IOLs were measured according to temperature from 26 degrees C to 32 degrees C in a transparent container filled with a mixture of OVDs and balanced salt solution. The unfolding time of each IOL was measured 4 times for each temperature. Unfolding time was defined as the time required for the folded IOL to recover >= 90% of its overall optic diameter before folding. In human trials, the unfolding time of the MX60 in a capsular bag filled with 30 degrees C OVDs was compared with that filled with room temperature OVDs for 4 cases in each group. Results: The unfolding time of the MX60 (215 +/- 25 seconds) was significantly longer than that of the SN60AT (28 +/- 7 seconds) and the ZCBOO (29 +/- 7 seconds) at 26 degrees C (p = 0.013). However, there were no differences in the unfolding time of 3 IOLs at 32 degrees C. In human trials, the unfolding time of the MX60 was shorter in a capsular bag filled with 30 degrees C OVDs (32 13 seconds) than if filled with OVDs kept at room temperature (127 27 seconds; p = 0.029). Conclusions: When fast and complete unfolding characteristics are needed, filling the anterior chamber and capsular bag with OVDs warmed to 30 degrees C before IOL implantation is recommended.