Quality of vision with the Acri.Twin asymmetric diffractive bifocal intraocular lens system

Purpose

To assess the quality of vision in patients who had implantation of asymmetric Acri.Twin bifocal diffractive intraocular lenses (IOLs) by evaluating distance and near visual acuities and photopic and mesopic contrast sensitivity under monocular and binocular conditions.

Setting

Fernández-Vega Ophthalmological Institute, Oviedo, Spain.

Methods

The study comprised 343 consecutive patients who had bilateral implantation of the Acri.Twin system: a distance-weighted 737D IOL and a near-weighted 733D IOL. Monocular and binocular best corrected distance visual acuities, best distance corrected near visual acuity, and distance contrast sensitivity under photopic (85 cd/m²) and mesopic (5 cd/m²) conditions were determined.

Results

Eyes with the 737D IOL had better best corrected distance acuity than eyes with the 733D IOL (mean 0.036 ± 0.061 logMAR versus 0.141 ± 0.131 logMAR) (P<.0001). Eyes with the 733D IOL had better best distance corrected near acuity than eyes with the 737D IOL (mean 0.015 ± 0.115 logMAR versus 0.059 ± 0.091 logMAR) (P = .0027). Binocularly, the Acri.Twin system allowed good distance and near vision; the means were 0.031 ± 0.059 logMAR and 0.005 ± 0.024 logMAR, respectively. Contrast sensitivity with the Acri.Twin system was within normal limits under photopic and mesopic conditions. Contrast sensitivity was statistically significantly better with the Acri.Twin system, followed by the 737D IOL and the 733D IOL under both illumination levels.

Conclusions

Asymmetric bilateral implantation of the Acri.Twin IOL gave good simultaneous distance and near vision with improved contrast sensitivity under photopic and mesopic conditions. Differences between monocular and binocular visual acuity and contrast sensitivity were obtained because of the distance-/near-weighted light distribution of Acri.Twin IOLs.