Depth of focus after implantation of spherical or aspheric intraocular lenses in hyperopic and emmetropic patients

Abstract

Purpose: To evaluate whether hyperopic patients with short axial length and high dioptric intraocular lens (IOL) power can achieve a higher depth of focus after implantation of a monofocal spherical or aspheric IOL than emmetropic patients.

Setting: Department of Ophthalmology, Medical University Graz, Graz, Austria.

Design: Prospective case series.

Methods: Patients presenting for cataract surgery were divided by calculated IOL power into a hyperopic (≥22.0 diopters [D]) or emmetropic (18.0 to 21.5 D) groups and received an aspheric (Tecnis ZA9003) or a spherical IOL (Sensar AR40e). Postoperative measurements included corrected (CDVA) and uncorrected (UDVA) distance visual acuities, distance-corrected intermediate (DCIVA) and near (DCNVA) visual acuities, root-mean-square values of corneal and total eye higher-order aberrations and spherical aberrations, and photopic and mesopic contrast sensitivity.

Results: Sixty-two eyes of 62 patients were enrolled in this study, 34 eyes (15 hyperopic, 19 emmetropic) in the aspheric IOL group and 28 eyes (14 hyperopic, 14 emmetropic) in the spherical IOL group. The UDVA, CDVA, and contrast sensitivity did not differ significantly between the 2 IOL groups, whereas the DCIVA and DCNVA were significantly better in the spherical IOL group (P = .004 and P = .001, respectively). No significant differences were found in DCIVA and DCNVA between hyperopic patients and emmetropic patients with aspheric or spherical IOLs.

Conclusions: Implantation of a monofocal spherical IOL resulted in an increased depth of focus without significant degradation of distance visual acuity or contrast sensitivity. There were no differences in the depth of focus between hyperopic eyes and emmetropic eyes.