To compare visual performance after bilateral implantation of a bifocal (ReSTOR +3.0 D) or trifocal (AT Lisa tri. 839MP) intraocular lens (IOL).

This prospective clinical study involved patients who had cataract surgery that included the bilateral implantation of a bifocal or trifocal IOL from April 2017 to May 2018 at Wuhan Aier Eye Hospital. Fifty-two eyes (26 patients) were implanted with a trifocal IOL (AT Lisa tri. 839MP) as trifocal group and fifty-two eyes (26 patients) with a bifocal IOL (ReSTOR +3.0 D) as bifocal IOL group. The follow-up was 3 months. Near, intermediate, and distance visual acuities, defocus curve, optical quality, including modulation transfer functions and intraocular aberrations, ocular aberrations with 3 mm and 5 mm pupil diameters, National Eye Institute Visual Functioning Questionnaire-14 for Chinese people (VF-14-CN), spectacle independence and patient satisfaction were assessed in all patients. Data were assessed with a Student's t test, Mann-Whitney U test, and Chi-square test.

No statistically significant difference was found in distance, near, best corrected distance, distance-corrected intermediate, or distance-corrected near visual acuity between the two groups. Uncorrected intermediate visual acuity was significantly better in the trifocal IOL group (Z=-2.347, P=0.019). In the binocular defocus curve, visual acuity was also significantly better for defocus at -1.0, -3.0, 3.5 and 4.0 diopters (Z=-2.619, -2.452, -2.452, -2.147; P=0.009, 0.014, 0.014, 0.032). No significant difference was found between the two groups for mean postoperative contrast sensitivity function under photopic conditions with or without glare. With a 3 mm or 5 mm pupil diameter, intraocular higher-order aberrations, coma, trefoil and total higher-order aberrations, and trefoil aberrations were significantly lower in the trifocal IOL group (P<0.05). With a 5 mm pupil diameter, intraocular spherical aberrations were significantly lower in the trifocal IOL group (Z=-3.053, P=0.002), but no statistically significant difference was found in modulation transfer function at 3 mm and 5 mm pupil diameters between the two groups. The level of overall satisfaction was similarly high for both groups.

Trifocal IOLs can provide significantly better intermediate vision and equivalent distance and near visual performance compared to bifocal IOLs and have the same level of overall satisfaction.

trifocal intraocular lens; defocus curve; contrast sensitivity; aberration; visual quality; optical quality