Peripheral Refraction and Contrast Detection Sensitivity in Pseudophakic Patients Implanted With a New Meniscus Intraocular Lens

Abstract

PURPOSE: To evaluate peripheral refraction and contrast detection sensitivity in pseudophakic patients implanted with a new type of inverted meniscus intraocular lens (IOL) (Art25; Voptica SL) that was designed to provide better peripheral optics. METHODS: One month after cataract surgery, in 87 eyes implanted with the Art25 IOL, peripheral contrast detection sensitivity was measured psychophysically at 40° visual angle, both horizontally and vertically, and compared with a control group of 51 eyes implanted with standard biconvex IOLs. Thirty-one eyes with the Art25 IOL and 28 eyes from the control group were randomly selected to also measure peripheral refraction using a scanning Hartmann-Shack wavefront sensor along 80° in the horizontal meridian. RESULTS: Most patients achieved emmetropia and good visual acuity, and no significant adverse events were observed after cataract surgery with Art25 IOLs. Peripheral contrast detection sensitivity was significantly better ( P < .01) in the group with the Art25 IOL in both directions (7.78 ± 3.24 vs 5.74 ± 2.60 vertical, 10.98 ± 5.09 vs 7.47 ± 3.96 horizontal), which was in agreement with the optical quality improvement in the periphery due to a reduction of defocus (1.97 and 1.21 diopters [D] at 40° temporal and nasal sides) and astigmatism (1.17 and 0.37 D at 40° temporal and nasal sides) that was statistically significant ( P < .01) from 20° of eccentricity. CONCLUSIONS: Patients implanted with a new inverted meniscus IOL present a reduced amount of peripheral defocus and astigmatism compared to patients implanted with standard biconvex IOLs. This improvement in optical quality leads to better contrast detection sensitivity measured at 40° of eccentricity. [ J Refract Surg . 2022;38(4):229–234.]

Peripheral defocus of monofocal intraocular lenses

“…Optical analyses show that a retinal image field that more closely mimics the peripheral defocus profile of the phakic eye with its crystalline lens can be achieved by using a concave convex meniscus lens instead of the traditional biconvex lens design. 2,8,10 The higher myopic peripheral defocus of IOLs compared with the crystalline lens could be a factor that contributes to the reduced peripheral visual performance observed in pseudophakic eyes. The finding suggests that the aphakic eye has hyperopic peripheral defocus relative to the retina that is compensated at least partially by the myopic relative peripheral defocus of the crystalline lens.…”

“…10 More recently, a meniscus IOL designed specifically to optimize retinal image quality in both the center and the periphery of the field has been developed, showing a significant reduction of peripheral defocus. 2,8 The decrease in peripheral retinal image quality found in earlier studies when the crystalline lens is replaced with an IOL is most likely due to differences in the power, shape, and axial position of the IOLs compared with the crystalline lens. 2,3 In particular, there can be large differences in power between the crystalline lens (typically around 24 diopters [D]) and the IOL depending on the preoperative refractive error.…”

“…revious clinical studies and computational modeling have shown that the retinal image in the peripheral visual field differs in pseudophakic eyes than in phakic eyes. [1][2][3][4][5][6][7][8] Recent studies found that the peripheral retinal image quality is degraded in pseudophakic patients and peripheral image degradation can affect visual function. 1,9 Reduced contrast and image quality in the periphery of the visual field could also affect diagnostic and imaging procedures in pseudophakic eyes, such as wide-field retinal imaging or visual field testing.…”

Peripheral visual field shifts after intraocular lens implantation

“…8,33 Similarly, a more different IOL geometry, such as the recently introduced meniscus-shaped optic, will likely have larger effects. 34 Frosting the IOL edge, another common IOL property, would induce a random scatter of rays that pass through the IOL edge resulting in a loss of relation to a specific retinal location. 35 Second, a rotationally symmetric model of the eye was used in these evaluations while it is known that the eye has a certain amount of asymmetry.…”

Central and peripheral refraction measured by a novel double-pass instrument

“…Intraocular lenses (IOLs) used in cataract surgery have been primarily designed as thin lenses to simplify surgical technique, resulting in increased peripheral astigmatism compared to the natural crystalline lens of the eye [ 7 ]. A recent study has shown that standard monofocal IOLs, commonly used in cataract surgery, can cause a decrease in the detection threshold in the far periphery [ 8 ] and the use of IOLs designed to improve peripheral image quality can increase peripheral field sensitivity [ 9 ]. Additionally, recent research shows a significant field distortion in the pseudophakic eye [ 10 ].…”