Purpose: The optical quality in the periphery of the retina in pseudophakic patients implanted with standard intraocular lenses (IOLs) is worse than those in the normal phakic eye (Jaeken et al., IOVS, 2013). This may affect specific visual tasks impacting patient’s orientation in space and therefore in their safety. We have evaluated peripheral astigmatism and contrast sensitivity in a group of patients implanted with a new type of IOL that was designed to provide better peripheral optics and compared with a group of patients implanted with a standard IOL.
Methods: A new type of IOL (ArtIOLs, Voptica SL, Murcia, Spain) with an inverted meniscus shape designed to improve the optical quality of the pseudophakic eye in the periphery was evaluated. These lenses were implanted in a group of 87 patients undergoing cataract surgery. A control group of 38 patients were implanted with a standard monofocal IOL as reference. Peripheral refraction in the horizontal meridian was measured using a scanning Hartmann-Shack wavefront sensor in every patient. The contrast detection threshold of the patients at 45 degrees of visual angle was estimated psychophysically by means of an adaptive staircase technique. A 30 arcmin round stimulus located at 1 m of the patient’s eyes was displayed at 45 degrees both horizontal and vertically. A green LED was used as foveal fixation.
Results: Patients implanted with ArtIOLs presented a reduced amount of peripheral astigmatism as compared with the control group. At 30 degrees, the average cylinder in the control group was 3D, reduced to 2 D in the ArtIOL’s group. At 45 degrees, cylinder were 6 D and 3.5 D respectively. This reduction in astigmatism had a positive impact in contrast sensitivity. In the horizontal meridian, average sensitivity values were 0.07 (SD=0.04) and 0.10 (SD=0.05) for the control and ArtIOL groups respectively. In the vertical meridian, average sensitivity values were 0.06 (SD=0.03) and 0.08 (SD=0.03) for the control and ArtIOL groups respectively.
Conclusions: : Patients implanted with a new meniscus-shape IOL present a reduced amount of peripheral astigmatism compared to patients implanted with standard lenses. This improvement in optical quality lead to a better contrast sensitivity measured at 45 degrees of eccentricity. Further research would be required to verify how this IOL may have also an impact in patient’s functional vision.
