Standard Results and Contrast Sensitivity Reestablishment after Implantation of a Trifocal Intraocular Lens

To assess, following the standards, the results of safety, efficacy and predictability for a trifocal intraocular lens and to evaluate contrast sensitivity and visual acuity defocus curve.

Fifty subjects operated on cataract surgery or refractive lens exchange with a trifocal intraocular lens have been recruited for the study. The monocular uncorrected visual acuity (VA) at far, intermediate (67 cm) and near (40 cm) distances in addition to corrected VA at far and near distances was evaluated at 1 week, 1 month and 3 months after surgery. Postoperative refraction, binocular contrast sensitivity function (CSF) and binocular defocus curves were also collected at the 3-month follow-up visit.

Mean uncorrected VA was 0.10, 0.07 and 0.05 logMAR at far, intermediate and near distances. Corrected distance VA at far and near distances was 0.04 and 0.02 logMAR. Ninety percent and 100% achieved a spherical equivalent in ±0.50 D and ±1.00 D, respectively. CSF was above normal range for 12 and 18 cycles per degree (cpd) in all the conditions, inside the normal range in 1.5, 3 and 6 cpd and only decreased below normal range for 1.5 and 3 cpd in mesopic vision without glare.

The procedure achieved a safety, efficacy and predictability similar to those reported by previous studies. The CSF was generally enhanced after the procedure in comparison to those reported in non-operated subjects above 60 years old. Previous studies might underestimate the effective distance of the intermediate and near foci.