Influence of Multifocal Intraocular Lenses on Standard Automated Perimetry Test Results

Importance: A multifocal intraocular lens (MFIOL) allows for spectacle independence after cataract surgery and is thus a seemingly attractive option. However, several optical limitations have been reported or can be hypothesized. Objective: To evaluate the influence of an MFIOL on standard automated perimetry (SAP) size III and size V test results. Design: Cross-sectional case-control. Setting: The University Medical Center Groningen and the Nij Smellinghe Hospital Drachten, the Netherlands. Participants: Sixteen eyes of 16 patients with a diffractive MFIOL (median age, 64 years), 18 phakic eyes of 18 healthy individuals serving as controls (median age, 62 years), and 12 eyes of 12 patients with a monofocal IOL (median age, 64 years) were included. Interventions: All participants underwent (1) SAP using a 30-2 grid and the Swedish Interactive Threshold Algorithm standard strategy with stimulus size III and (2) a full threshold test with stimulus size V. Main Outcome Measures: Primary outcome measures were the mean deviation (MD) for size III and the mean sensitivity (MS) for size V. Comparisons between groups were adjusted for age and pupil size. Results: For SAP size III, the average difference in MD between patients in the MFIOL group and phakic controls was -2.40 dB (P<.001) and between patients in the monofocal IOL group and phakic controls was -0.32 dB (P=.52). For SAP size V, the corresponding differences in MS were -1.61 dB (P=.002) and -0.80 dB (P=.09), respectively. The differences were essentially independent of eccentricity for both SAP size III and SAP size V. Conclusions and Relevance: Patients with a diffractive MFIOL have a clinically relevant reduction of the visual sensitivity as assessed with SAP size III and size V. The reduction seems to be related to the multifocal design of the IOL rather than to pseudophakia. The reduction interferes with the assessment of common eye diseases such as glaucoma and comes on top of the decline of visual sensitivity due to normal aging or age-related eye diseases, thus potentially accelerating visual impairment.