Abstract
Purpose:
To evaluate visual performance/perception in patients with simulated multifocal corrections, using a novel hand-held simultaneous vision simulator and clinically-suited visual tests. To identify the optimal multifocal correction in individual patients.
Methods:
5 cyclopeged subjects were evaluated with a miniaturized see-thru simultaneous vision simulator. Multifocal corrections are simulated by a tunable lens (Optotune, AG) operating in temporal multiplexing, able to scan through a 3-diopters (D) addition focus range at 50 Hz, giving a static appearance of multifocal retinal images. Evaluation of the lens by HS-aberrometry and laser ray tracing focimetry reveal high linear response of optical power vs voltage (r=0.997), high optical quality (RMS<0.05 μm), and high reproducibility of thru-focus energy distribution. Seven lenses were simulated, with different energy distributions at far (F) intermediate (I; 1.5D add) and near (N; 3D add): 3 monofocal (100F, 100I & 100N), 2 bifocal (50F50N & 70F30N) and 2 trifocal (33F33I33N & 50F20I30N) patterns. With each lens, high contrast visual acuity (VA) was measured at F, I and N distances using randomized optotypes on a high definition display. Also, subjects scored the perceived quality of a real visual scene containing F, I and N targets, and compared visual quality (2AFC) through 60 random pairs of multifocal corrections.
Results:
Average logMAR VA at F ranged between -0.05 (100F) and 0.52 (100N) for monofocal, and between 0.17 (50F20I30N) and 0.43 (33F33I33N) for multifocal corrections (mean 0.25). VA ranges at N were 0.12 (100N) to 0.61 (100F) with monofocal, and 0.26 (50F50N) to 0.42 (70F30N) with multifocal corrections (mean 0.31). Highest multifocal VA at I (0.25) was found for 33F33I33N. On average across distances the highest VA and perceptual scores were found for 100I. Direct comparisons revealed a systematic preference of 50F50N over 70F30N and 50F20I30N over 33F33I33N. However, consistent intersubject differences occurred in VA and perception with the different multifocal corrections.
Conclusions:
Temporal multiplexing of a tunable lens provides new ways to simulate multifocal corrections, mimicking existing IOLs/CLs. All multifocal designs outperform monofocal corrections focused at far and near, but not at intermediate distance. Visual quality differed across multifocal designs and patients.