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

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 (enVista MX60, AcrySof SN60AT, and Tecnis 1 ZCB00). Methods The unfolding times of 3 kinds of IOLs were measured according to temperature from 26°C to 32°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°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 ZCB00 (29 ± 7 seconds) at 26°C (p = 0.013). However, there were no differences in the unfolding time of 3 IOLs at 32°C. In human trials, the unfolding time of the MX60 was shorter in a capsular bag filled with 30°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°C before IOL implantation is recommended.