Purpose: To evaluate distance and near contrast sensitivity under photopic and mesopic conditions before and after refractive lens exchange (RLE) with implantation of a diffractive multifocal intraocular lens (IOL).
Setting: University of Valencia, Valencia, Spain.
Methods: Monocular contrast sensitivity function was measured with the Functional Acuity Contrast Test chart at distance and near under 3 luminance levels (85.0 cd/m(2), 5.0 cd/m(2), and 2.5 cd/m(2)) before and after RLE with bilateral AcrySof ReSTOR IOL implantation in 30 hyperopic eyes with presbyopia and low astigmatism (<or=1.0 diopter). Results after surgery were compared with those before surgery.
Results: Six months postoperatively, the mean residual spherical equivalent refractive error was 0.21 diopter+/-0.19 (SD). The best corrected distance and near visual acuities were comparable to those before surgery. For distance vision, the safety index was 1.02 and the efficacy index was 0.91. For near vision, the values were 1.04 and 1.02, respectively. There were no statistically significant differences between preoperative and postoperative results at any distance or spatial frequency or under any lighting condition (P>.1, t test).
Conclusions: Refractive lens exchange with implantation of a diffractive multifocal IOL gave good distance and near contrast sensitivity under photopic and mesopic conditions. Although mesopic contrast sensitivity was reduced at distance and near compared to that under photopic conditions, the performance was comparable to that with the natural lens preoperatively.