Comparison of a trifocal intraocular lens with a+3.0 D bifocal IOL: results of a prospective randomized clinical trial

Purpose To compare visual outcomes in patients with cataract surgery and bilateral implantation of a trifocal or bifocal intraocular lens (IOL). Setting University Eye Clinic Maastricht, the Netherlands. Design Prospective randomized clinical trial. Methods Eyes with cataract and less than 1.0 diopter (D) of corneal astigmatism were randomized to receive bilateral implantation of Finevision Micro F trifocal IOLs or Acrysof IQ Restor +3.0 bifocal IOLs. Outcome measures were monocular and binocular uncorrected distance (UDVA), uncorrected intermediate (UIVA), and uncorrected near (UNVA) visual acuities; refractive outcomes; binocular defocus curve; contrast sensitivity; reading speed; patient satisfaction; and spectacle independence. Results Six months postoperatively, the mean binocular UDVA, UIVA, and UNVA in 56 eyes of 28 patients were 0.01 logMAR ± 0.11 (SD), 0.32 ± 0.15 logMAR, and 0.15 ± 0.13 logMAR in the trifocal group (n = 15) and 0.00 ± 0.09 logMAR, 0.28 ± 0.08 logMAR, and 0.12 ± 0.08 logMAR in the bifocal group (n = 13), respectively. The trifocal group showed a more continuous defocus curve and better results at −1.0 D of defocus (P < .01). The mean mesopic contrast sensitivity was higher in the bifocal group (P = .02). Complete spectacle independence was reported by 80% of trifocal patients and 50% of bifocal patients. There were no significant differences in refractive outcomes, reading speed, or patient satisfaction. Conclusion This study showed noninferiority of visual outcomes with the trifocal IOL compared with the bifocal IOL, although the defocus curve was better at an intermediate distance with the trifocal IOL. Financial Disclosure Dr. Bauer received study grants from Alcon Laboratories, Inc., Carl Zeiss Meditec AG, and Physiol S.A. and a lecture fee from Alcon Surgical, Inc. Dr. Nuijts is a consultant to Alcon Surgical, Inc., Théa Pharma GmbH, and ASICO LLC; he has received study grants from Acufocus, Inc., Alcon Surgical, Inc., Carl Zeiss Meditec AG, Ophtec BV, and Physiol S.A. No other author has a financial or proprietary interest in any material or method mentioned. Cataract is an age-related eye disease leading to an impairment of patients’ daily functioning as well as optical disturbances such as glare and halos.1 In 2010, an estimated 95 million people worldwide had cataracts.2 Surgical removal of the crystalline lens and replacement with an artificial intraocular lens (IOL) is the only vision-restoring option. After implantation of a monofocal IOL, reading glasses are usually needed for near vision, whereas multifocal IOLs result in better uncorrected near visual acuity (UNVA) with a reduced overall spectacle dependence.1, 3 and 4 Multifocal IOLs function by projecting multiple images on the retina, which may result in unwanted visual phenomena such as contrast reduction, glare, and halos.3, 4, 5, 6, 7, 8, 9, 10, 11 and 12 Because most multifocal IOLs have only 2 foci, near and far, the quality of intermediate visual acuity might be insufficient for successful functioning in daily life.13 and 14 Trifocal IOLs have been developed to improve vision at intermediate distances.13 and 15 The goal of this randomized clinical trial was to compare the visual outcomes of a new trifocal IOL with those of a commonly used bifocal IOL. Patients and methods Patient Selection A randomized clinical study design was used to compare visual function and patient satisfaction after bilateral IOL implantation in patients treated for age-related cataract. Both patient enrollment and treatment took place at the University Eye Clinic Maastricht. Approval from the medical ethics committee was obtained, and all procedures were conducted according to the Declaration of Helsinki. Written informed consent was obtained from all patients. Inclusion criteria were bilateral cataract, less than 1.0 diopter (D) corneal astigmatism in both eyes, age over 42 years, and an expected postoperative corrected distance visual acuity (CDVA) of 0.3 logMAR or less. Exclusion criteria were combined ocular procedures, previous ocular surgery, ocular pathology that would limit postoperative visual outcome, suturing of the incision during surgery, and complications during surgery in the first eye. After enrollment, random allocation of study patients was performed to bilateral implantation of a trifocal IOL (trifocal group) or a bifocal IOL (bifocal group). Patients and investigators were masked. Surgical Technique Two experienced surgeons (N.B., R.N.) performed all surgical procedures, which consisted of a standard phacoemulsification technique through a 2.2 mm clear corneal incision. Surgery in the second eye was performed within 2 weeks of the first surgery in each patient. The same type of IOL was implanted in both eyes. The study used 2 types of IOLs: the Finevision Micro F trifocal IOL (Physiol S.A.) (Figure 1) and the Acrysof Restor IQ +3.0 D bifocal IOL (Alcon Surgical, Inc.) (Figure 2). The trifocal IOL is a foldable single-piece fully diffractive pupil-dependent aspheric IOL made of a hydrophilic acrylic with an ultraviolet (UV)- and blue-light inhibitor.13 and 15 It has an optic diameter of 6.15 mm, an overall diameter of 10.75 mm, and a 4-point haptic design for stability. It has +3.5 D additional power for near vision and +1.75 D additional power for intermediate vision, consists of 26 diffractive steps, and requires a minimum incision of 1.8 mm. The bifocal IOL is a foldable, single-piece, pupil-dependent aspheric biconvex IOL with a 3.6 mm center and 9 apodized diffractive steps.15 It is made of a hydrophobic acrylate/methacrylate copolymer with an UV-light and blue-light blocker. The optic diameter is 6.0 mm, and the overall diameter is 13.0 mm. It has +3.0 D additional power for near vision.