Effect of the color of the intraocular lens on optical and visual quality

Abstract

Purpose: To analyze the optical quality of intraocular lenses (IOL) with an orange (PC440Y) and a yellow (SN60AT) filter, and correlate these results with the visual quality of patients with these implants. Setting: Fisabio Oftalmologνa Mιdica, Valencia, Spain. Design: Randomized prospective study. Materials and Methods: The IOL optical quality was determined using the modulation transfer function (MTF) and the spectral transmission. The visual quality of 87 eyes with cataract (51 with orange filter and 36 with yellow filter) was determined by best corrected visual acuity (BCVA) and contrast sensitivity function (CSF) under photopic and mesopic conditions. To analyze the results, we use a Student's t-test. Results: Orange lens filtered more of the blue spectrum (cut-off wavelength of 370 nm) than the yellow lens (390 nm). The MTF of the yellow lens was better than the orange lens (average modulation of 0.676 for natural and 0.672 for orange). The patients' BCVA was 0.02 + 0.10 logMAR for both lenses. The CSF obtained with the yellow lens was slightly better, although without statistically significant differences (P > 0.05). Conclusions: Both lenses are of good optical quality. The patients' visual quality was similar with both lenses, and optical quality was also similar. The color of the lens does not affect the visual quality of the patient.

Figure 1

Spectral transmission orange and yellow filter lenses (a) and modulation transfer function (MTF) of both lenses (b) Solid line represents yellow filter lens and dotted line represents orange lens. In Figure 1b dashed-dotted line represents MTF of an ideal system without aberration effects and limited only by diffraction c/mm: Cicles/mm

Figure 2

Photopic (continuous line) and mesopic (dashed line) contrast sensitivity function of patients with yellow lens (top) and orange lens (bottom). The values associated at each spatial frequency on the graph are the ‘P’ values, and show when the dots representing the same spatial frequency are statistically different (cycles per degree)

Figure 3

Mean of the contrast sensitivity differences between photopic and mesopic illumination conditions for each patient for both lenses (orange: empty squares; yellow: filled squares). The values associated at each spatial frequency on the graph are the ‘P’ values, and show when the dots representing the same spatial frequency are statistically different (cycles per degree)