Clinical Outcomes of Patients Fitted with Bifocal and Trifocal Diffractive Intraocular Lenses

Purpose: We compared the short-term visual outcomes of patients fitted with trifocal diffractive intraocular lenses (IOLs) and bifocal IOLs 3 months after IOL implantation. Methods: We included 38 eyes undergoing IOL implantation at a single tertiary hospital. In all, 21 eyes received bifocal IOLs (TECNIS (R) 1 ZLB00; Abbott Medical Optics Inc., Santa Ana, CA, USA) and 17 received trifocal diffractive IOLs (FineVision (R) POD F; PhysIOL SA, Liege, Belgium). The primary outcomes were corrected and uncorrected visual acuities at 4 m, 50 cm, and 33 cm on postoperative weeks 1, 4, and 12, and the spherical equivalence values at those times. The secondary outcomes included contrast sensitivity measured using an Optec 6500. instrument (Stereo Optical Co. Inc., Chicago, IL, USA) 4 weeks after surgery, the numbers of total and internal optical aberrations assessed using the iTrace (R) (Tracey Technologies, Houston, TX, USA) instrument at 12 weeks, symptoms including glare or halo, and the need for spectacles when engaging in daily activity. Results: One week after surgery, eyes implanted with trifocal IOLs exhibited significantly better uncorrected near vision compared to eyes that had received bifocal IOLs, and at weeks 4 and 12, uncorrected intermediate vision was also better in the former eyes. The mean spherical equivalence did not significantly differ between the two groups, nor did the contrast sensitivity measured on postoperative week 4 or the numbers of optical aberrations evident at postoperative week 12. Eyes fitted with trifocal IOLs appeared to suffer less from glare or halo, but the between-group difference was not significant. The two groups did not significantly differ in terms of the need to wear supplementary spectacles. Conclusions: Trifocal diffractive IOLs seem to afford superior intermediate vision compared to traditional bifocal IOLs, and may therefore improve visual outcomes at varying distances in patients undergoing cataract surgery.