Cari Pérez-Vives

In vitro optical performance of nonrotational symmetric and refractive-diffractive aspheric multifocal intraocular lenses: impact of tilt and decentration.

Purpose To evaluate the optical quality of Acrysof Restor SN6AD1 refractive–diffractive +3.00 D and Lentis Mplus LS‐312 nonrotational symmetric +3.00 D aspheric multifocal intraocular lenses (IOLs) and analyze the effect of tilt and decentration. Setting University of Valencia, Valencia, and University of Murcia, Murcia, Spain. Design Experimental study. Methods An artificial model eye was used to measure wavefront aberrations of both IOL models. The modulation transfer function (MTF) and point‐spread function (PSF) were calculated for a 5.0 mm pupil and under 5 situations: centered, 0.2 mm and 0.4 mm decentered, and 2 degrees and 4 degrees tilted. Results The refractive–diffractive IOL had the highest MTF values at all spatial frequencies. Similarly, the PSF was worse for the refractive–diffractive IOL. The MTFs for the refractive–diffractive IOL decreased when the IOL was decentered or tilted, being more robust for tilting than decentration. The MTFs for the nonrotational symmetric IOL were similar under all testing conditions. Cutoff frequencies for the refractive–diffractive IOL were stable over the range of tilting studied and comparable with the cutoff when the IOL was centered (approximately 50 cycles per degree [cpd]). When the IOL was decentered, the cutoff frequency decreased by approximately 40 cpd. The nonrotational symmetric IOL cutoff frequencies for misalignment and tilt were low (approximately 30 cpd) and similar under all conditions. Conclusions The refractive–diffractive IOL provided better optical quality than the nonrotational symmetric IOL. Tilt and decentration had a significant impact on optical quality with both IOLs, being more severe with the nonrotational symmetric IOL. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.

Visual simulation through different intraocular lenses using adaptive optics: Effect of tilt and decentration

PURPOSE: To analyze visual quality differences between intraocular lenses (IOLs) and assess the impact of IOL decentration and tilt on visual quality. SETTING: University of Valencia, Valencia, Spain. DESIGN: Cohort study. METHODS: The crx1 adaptive optics visual simulator was used to simulate the wavefront aberration pattern of 2 commercially available aspheric aberration‐correcting IOLs (Acrysof IQ SN60WF and Tecnis ZA9003) and 2 spherical IOLs (Akreos Adapt and Triplato) in 5 situations: centered, decentered 0.2 mm and 0.4 mm, and tilted 2 degrees and 4 degrees. Monocular distance visual acuity at 100%, 50%, and 10% contrast and the depth of focus were measured. RESULTS: Ten eyes of 10 patients were evaluated. When the IOLs were centered, there were no differences in visual acuity between the 4 IOLs at any contrast. The aberration‐correcting IOLs were more sensitive to tilt and decentration than the spherical IOLs; Tecnis ZA9003 IOL was the most sensitive to decentration and the Acrysof IQ SN60WF IOL was the most sensitive to tilt. Higher residual spherical aberration slightly improved depth of focus and the tolerance to defocus. CONCLUSIONS: The results in this study suggest that the aspheric aberration‐correcting and spherical IOLs provided comparable visual quality when centered in eyes in which the corneal higher‐order aberrations are those of the average of the human cornea. Tilt and decentration of the IOLs had an impact on visual quality, with aberration‐correcting IOLs having a greater effect than the spherical IOLs. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.

Prevalence of cataract after collagen copolymer phakic intraocular lens implantation for myopia, hyperopia, and astigmatism

Purpose To evaluate the prevalence of cataract after Implantable Collamer Lens phakic intraocular lens (pIOL) implantation with different models at different ages and for different refractive powers. Setting Fernández‐Vega Ophthalmological Institute, Oviedo, Spain. Design Retrospective nonrandomized clinical study. Methods The pIOL (models V4, V4b, or V4c) was implanted in all cases. Results The study included 3420 eyes (1898 patients). The mean patient age at surgery was 31.2 years ± 6.4 (SD) (range 18 to 50 years) and the mean spherical refractive error, −7.27 ± 5.24 diopters (D) (range −26.5 to 12.5 D). Twenty‐one eyes (0.61%) of 15 patients had pIOL explantation (all model V4) because cataract developed. The mean age of the patients who had explantation was 39.43 ± 4.57 years; 7 were younger than 40 years, and 8 were 40 years or older. The mean spherical equivalent was −10.1 ± 5.41 D; 3 eyes had a pIOL power less than −10.50 D, 4 eyes between −10.50 D and −13.50 D, and 14 higher than −13.50 D. The mean time between pIOL implantation and cataract surgery was 4.2 ± 1.8 years. No eye with implantation of the latest models (V4b and V4c) developed cataract. The mean vault distance in eyes that developed cataracts was 103 ± 69 &mgr;m. Conclusions The incidence of cataract was low after pIOL implantation at the 6‐year follow‐up. The rate of cataract was higher in older patients and in those with high refractive errors. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.

Optical quality of the Visian Implantable Collamer Lens for different refractive powers

PurposeTo evaluate the optical quality of the Visian Implantable Collamer Lens (ICL) for different powers and pupil diameters.MethodsWavefront aberrations of the −3, −6, −9, −12 and −15 diopters (D) V4b ICLs were measured at 3- and 4.5-mm pupils. The root mean square (RMS) of total higher order aberrations (HOAs), trefoil, coma, tetrafoil, secondary astigmatism, and spherical aberration were evaluated. In addition, modulation transfer function (MTF) of the five ICL powers was measured for a 3-mm pupil. The point spread functions (PSFs) of each ICL evaluated was calculated from the wavefront aberrations at 4.5-mm pupil.ResultsThe ICLs evaluated had negative spherical aberration and negligible amounts of other aberrations. The negative spherical aberration increases when the ICL power increases being related with its innate optical properties. At 3-mm pupil, no statistically significant differences between ICLs were found for all the Zernike coefficient RMS values analyzed (p > 0.05). At 4.5-mm pupil, significant RMS values for the spherical aberration and total HOAs were found between medium-low and high powers (p < 0.05). Similar MTFs were obtained for all ICLs, although they slightly worsened when increased the ICL power.ConclusionsICLs evaluated provide good optical quality in terms of wavefront aberrations, MTF, and PSF. Although spherical aberration increases with ICL power, these values are clinically negligible to affect the visual quality after its implantation.

Optical and visual quality comparison of implantable Collamer lens and laser in situ keratomileusis for myopia using an adaptive optics visual simulator.

Purpose. To compare optical and visual quality of the implantable Collamer lens (ICL) and laser in situ keratomileusis (LASIK) for myopia. Methods. An adaptive optics visual simulator (CRX1, Imagine Eyes, France) was used to simulate the vision after ICL implantation and LASIK procedure from the wavefront aberration pattern for −3 and −6 D. Monocular visual acuity (VA) at different contrasts and contrast sensitivity (CS) at 10, 20, and 25 cycles/degree (cpd) were measured for 3- and 5-mm pupils. Modulation transfer function (MTF) and point spread function (PSF) were calculated for a 5-mm pupil. Results. The ICL showed a MTF near of diffraction-limited MTF, but the post-LASIK of MTF worsened moving away from both curves. Statistically significant differences were found in VA between both procedures for all conditions (p<0.05). For −3 D ICL and LASIK, we did not find statistically significant differences in CS between the procedures for both pupils and any spatial frequencies (p>0.05). But for −6 D ICL and LASIK, the effect of aberrations became apparent, finding statistically significant differences in CS between both procedures for 2 pupils and all spatial frequencies evaluated (p<0.05). In all cases optical and visual quality was better with the ICL procedure. Conclusions. Both ICL and LASIK procedures provide good optical and visual quality, although the ICL provides better outcomes, especially for large refractive errors and pupil sizes. These outcomes are due to the LASIK procedure inducing higher higher-order aberrations than ICL implantation.

Optical quality comparison between spherical and aspheric toric intraocular lenses

Purpose To measure and compare the optical quality of spherical and aspheric toric intraocular lenses (IOLs). Methods Wavefront aberrations of AcrySof Toric and IQ Toric IOLs (Alcon Laboratories) for different powers were measured at 3- and 5-mm pupils by Nimo TR0805 instrument. The Zernike coefficients of trefoil, coma, tetrafoil, secondary astigmatism, and spherical aberration were evaluated. The point spread functions (PSFs) of each IOL evaluated were calculated from the wavefront aberrations. The PSF images also were calculated from the IOL wavefront aberrations, adding the corneas aberrations to simulate the optical quality after their implantation. Results Spherical toric IOLs showed positive and aspheric toric IOLs negative spherical aberrations. Statistically significant differences were found in spherical aberration root mean square (RMS) values between spherical and aspheric IOLs for both pupil sizes (p<0.05). Aspheric toric IOLs showed higher spherical aberration RMS values. We found differences in PSF images between both IOL designs at 5-mm pupil. The PSFs corresponding to the aspheric toric IOLs showed more spread out than the PSFs corresponding to the spherical toric IOLs. However, when corneal aberrations were added, aspheric toric IOLs showed better optical quality than spherical toric IOLs. Conclusions At 3-mm pupil, the optical quality between the IOL designs was similar, but at 5-mm pupil the optical quality was higher for spherical IOLs than aspheric IOLs. However, when theoretical corneal aberrations were added, aspheric toric IOLs showed better optical quality than spherical toric IOLs, due to the compensation between aspheric toric IOL negative spherical aberration and corneal positive spherical aberration.

Optical and Visual Quality of the Visian Implantable Collamer Lens Using an Adaptive-Optics Visual Simulator

PURPOSE To evaluate visual and optical quality of the implantable collamer lens for different powers and sizes of incision surgery. DESIGN Prospective study in humans. METHODS An adaptive optics visual simulator was used to measure 3 powers of implantable collamer lenses and simulate the implantable collamer lens wavefront aberrations pattern for small- and large-incision surgery. Visual acuity (VA) and contrast sensitivity were measured in 11 observers for 3- and 5-mm pupils. Modulation transfer function, point spread function, and Strehl ratio were calculated. RESULTS At 3 mm pupil, no statistically significant differences were found between both incision sizes for any implantable collamer lens power, except for -15 diopter (D) implantable collamer lens at 25 cycles/degree (cpd) (P < .05). At 5 mm pupil, statistically significant differences in Strehl ratio, VA, and contrast sensitivity were found between both incision sizes for all implantable collamer lens powers (P < .05). The outcomes were better with small incision. Implantable collamer lens power also affected the optical and visual quality. At 3 mm pupil, no statistically significant differences were found in VA and contrast sensitivity between implantable collamer lens powers, except between -3 and -15 D at low-contrast VA and at 20 and 25 cpd (P < .05). At 5 mm pupil, no statistically significant differences were found in Strehl ratio, VA, and contrast sensitivity between -3 and -6 D implantable collamer lens, but they did become apparent for -15 D implantable collamer lens for both incision sizes, all contrasts and spatial frequencies (P < .05). CONCLUSIONS The implantable collamer lens provides good optical and visual quality, although these outcomes decreased with large-incision surgery because of the increase of aberrations.

Visual quality comparison of conventional and Hole-Visian implantable collamer lens at different degrees of decentering

Purpose To compare the visual quality of implantable collamer lens (ICL) with and without central hole (Hole ICL and conventional ICL) at different degrees of decentering. Methods An adaptive optics visual simulator (crx1, Imagine Eyes, Orsay, France) was used to simulate the –3, –6 and –12 dioptres (D) conventional and Hole ICLs in three conditions: centred and decentred 0.3 and 0.6 mm. Visual acuity (VA) at high-contrast, medium-contrast and low-contrast and contrast sensitivity (CS) were measured in 15 observers for 3 and 4.5 mm pupils. Results No statistically significant differences in VA and CS were found between conventional and Hole ICLs for any ICL powers and pupil sizes evaluated (p>0.05). Regarding the effect of the ICL decentration on visual performance, we did not find statistically significant differences in VA and CS between centred, 0.3 and 0.6 mm decentred (p>0.05). Moreover, the ICL decentration affected the same manner on the conventional and Hole ICLs. Conclusions The outcomes showed that conventional and Hole ICLs provided good and comparable visual performance for all powers and pupil sizes evaluated. Besides, ICL decentering affects the same manner both ICL models evaluated. The ICL decentering did not have any effect on the visual performance.

Myopic astigmatism correction: comparison of a Toric Implantable Collamer Lens and a bioptics technique by an adaptive optics visual simulator

To compare the optical and visual quality of a simulated Toric Implantable Collamer Lens (TICL) and a bioptics technique to treat high myopic astigmatism.

Depth of Focus Through Different Intraocular Lenses in Patients With Different Corneal Profiles Using Adaptive Optics Visual Simulation

PURPOSE To evaluate the depth of focus with monofocal intraocular lenses (IOLs) in patients with different corneal profiles using adaptive optics (AO) visual simulation. METHODS An AO visual simulator (crx1, Imagine Eyes) was used to simulate the aberration pattern of three monofocal IOLs (Acrysof IQ SN60WF [Alcon Laboratories Inc]; Akreos Adapt AO [Bausch & Lomb]; and Triplato [AJL Ophthalmic]) of different optic designs. Five groups were considered: patients without any corneal refractive surgery (normal cornea group) and with prior low and high myopic and hyperopic ablations (low myopic ablation, high myopic ablation, low hyperopic ablation, and high hyperopic ablation groups). Defocus curves for all situations were measured, with the target being moved from -5.00 to +2.50 diopters (D) in 0.25-D steps, and visual acuity was measured at all vergences. RESULTS Ten eyes from 10 patients were evaluated. The higher residual spherical aberration (SA) for all IOLs was obtained for the high myopic ablation group and the most negative residual SA was obtained for the high hyperopic ablation group. The best compromise between distance visual and depth of focus for the normal cornea, low myopic ablation, and high myopic ablation groups was obtained with the aspheric designs, whereas the best results for the low hyperopic and high hyperopic ablation groups were obtained with the spherical IOL. CONCLUSIONS The results of this study suggest that the better compromise between distance visual acuity and depth of focus with the three IOLs and the different corneal profiles relies on a certain amount of positive SA. Above a certain limit of residual SA (positive or negative), visual acuity decreases at all vergences, worsening the depth of focus.