Javier Ruiz-Alcocer

Optical quality differences between three multifocal intraocular lenses: bifocal low add, bifocal moderate add, and trifocal.

PURPOSE To compare the in vitro optical quality at different focal points of two new bifocal intraocular lenses (IOLs) and one new trifocal IOL. METHODS The AcrySof ReSTOR SV25T0 (+2.5 diopter [D] add) and the AcrySof ReSTOR SN6AD1 (+3.0 D add) with two main foci (Alcon Laboratories, Fort Worth, TX) and the AT LISA tri 839MP with three main foci (Carl Zeiss Meditec, Dublin, CA) were evaluated. The optical quality of the IOLs was measured with the PMTF optical bench (LAMBDA-X, Nivelles, Belgium). The optical quality of the IOLs was quantified by the modulation transfer function (MTF) at five different focal points (0.0, -1.5, -2.0, -2.5, and -3.0 D) and for 3.0- and 4.5-mm apertures. The through-focus MTF of the IOLs was also recorded. RESULTS For the 0.0 D focal point, the AcrySof ReSTOR (+2.5 D add) obtained the highest MTF values for all apertures. For the -2.5 D focal point, the AcrySof ReSTOR (+3.0 D add) showed the highest MTF values for 3.0 mm. For the -3.0 D focal point at 3.0- and 4.5-mm aperture, the best values were obtained with the AcrySof ReSTOR (+3.0 D add) and the AT LISA, respectively. For the -1.5 D focal point, the trifocal IOL provided better values. For the -2.0 D focal point, all IOLs provided comparable results. The through-focus MTF curves showed three and two peaks for the trifocal and bifocal IOLs, respectively. CONCLUSIONS The trifocal IOL provides a better optical quality at the -1.5 D focal point. However, the optical quality of the trifocal IOL significantly decreases compared to the bifocal IOLs at far distance and -2.5 D focal points.

In vitro optical quality differences between multifocal apodized diffractive intraocular lenses.

Purpose To compare the in vitro optical quality of multifocal apodized intraocular lenses (IOLs) at different focal points. Setting University of Valencia, Valencia, Spain. Design Experimental study. Methods The Acrysof Restor +3.0 diopter (D) multifocal IOL with 2 main foci (bifocal IOL) and the Finevision multifocal IOL with 3 main foci (trifocal IOL) were evaluated. The optical quality was quantified using the modulation transfer function (MTF) at 7 focal points and for 3.0 mm and 4.5 mm apertures. The through‐focus MTF at 10 focal points of the IOLs was also recorded. Results For the 0.0 D and −2.5 D focal points, the bifocal IOL showed the highest MTF values for pupil sizes as well as for the −3.0 D focal point for a 3.0 mm aperture. For the −1.5 D and −3.5 D focal points, the trifocal IOL provided better MTF values, whereas for −2.0 D and −4.0 D both IOLs provided comparable results for both apertures. The through‐focus MTF curves showed 3 and 2 peaks for the trifocal IOL and the bifocal IOL, respectively. With the bifocal IOL, better peak values were obtained at the 0.0 D, −2.0 D, −2.5 D, and −3.0 D focal points, while the trifocal IOL yielded better peak values at the −1.5 D and −3.5 D focal points. Conclusion The bifocal IOL is likely to provide a greater range of vision from distance to near than the trifocal IOL; however, at the intermediate focal point (−1.5 D), the trifocal IOL will probably yield better optical quality. 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.

Optical performance of two new trifocal intraocular lenses: through-focus modulation transfer function and influence of pupil size.

To compare the in vitro optical quality of two new trifocal intraocular lenses at different focal points as a function of pupil size.

Visual simulation through different intraocular lenses in patients with previous myopic corneal ablation using adaptive optics: effect of tilt and decentration.

PURPOSE: To evaluate visual quality differences between intraocular lenses (IOLs) in patients with previous myopic laser ablations and assess the impact of IOL decentration and tilt on visual quality. SETTING: University of Valencia, Burjassot, Spain. DESIGN: Cohort study. METHODS: An adaptive optics visual simulator was used to simulate the wavefront aberration pattern of 1 aberration‐correcting IOL (Acrysof IQ SN60WF), 1 aberration‐free IOL (Akreos Adapt AO), and 1 spherical IOL (Triplato) under 5 IOL situations: centered, 0.2 mm and 0.4 mm decentered, and 2 degrees and 4 degrees tilted in eyes with simulated low or high myopic laser corneal ablations. Monocular distance visual acuity at 100%, 50%, and 10% contrast were measured. RESULTS: Ten eyes of 10 patients were evaluated. When the IOLs were centered, the aberration‐correcting IOL provided the best visual quality results in both groups. When the IOLs were misaligned, there was a decrease of visual quality with all simulated IOLs except the aberration‐free IOL in the high myopia group. In the misaligned situations, all simulated IOLs obtained comparable visual quality results in both groups. CONCLUSIONS: The results suggest that in patients with previous myopic laser corneal ablation, aberration‐correcting IOLs should be implanted. The decrease in visual quality when these IOLs are decentered or tilted demonstrates the importance of accurate implantation of these IOLs. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.

Effect of simulated IOL tilt and decentration on spherical aberration after hyperopic LASIK for different intraocular lenses.

PURPOSE To evaluate visual quality differences among intraocular lenses (IOLs) in patients with previous hyperopic laser ablations and to assess the impact of decentration and tilt of IOLs on visual quality. METHODS An adaptive optics visual simulator was used to simulate the wavefront aberration pattern of one aberration-correcting IOL (AcrySof IQ SN60WF, Alcon Laboratories Inc) and two spherical IOLs with different amounts of positive spherical aberration (Akreos Adapt [Bausch & Lomb] and Triplato [AJL Ophthalmic]) in five situations-centered, 0.2 mm and 0.4 mm of decentration, and 2° and 4° of tilt-in two groups: simulated low hyperopic laser corneal ablation (low hyperopia group) and high hyperopic laser corneal ablation (high hyperopia group). Monocular distance visual acuity at 100%, 50%, and 10% contrast were measured. RESULTS Ten eyes were evaluated. When the IOLs were centered, all IOLs obtained comparable results for the low hyperopia group, whereas for the high hyperopia group, the Akreos Adapt and AcrySof IQ SN60WF showed better visual acuity than the Triplato. When the IOLs were misaligned, for the low hyperopia group, the best visual acuity results were obtained with the Akreos Adapt and the most critical situation was at 0.4 mm of decentration. For the high hyperopia group, misalignments decreased visual acuity in a higher amount than for the low hyperopia group. CONCLUSIONS Our results suggest that the IOLs studied offer good visual quality when they are centered for both groups. However, tilt and decentration of monofocal IOLs have an impact on visual function in patients with hyperopic ablations. For these patients, the Akreos Adapt is the most robust to misalignments.

Changes in accommodative responses with multifocal contact lenses: a pilot study.

Purpose. To evaluate induced changes in pupil and accommodative response for different accommodative stimuli with three different multifocal contact lenses (CLs). Methods. Accommodative and pupil responses with three aspheric multifocal CLs of simultaneous focus center near (PureVision Low Add, PureVision High Add and Focus Progressives) for two accommodative stimuli of −2.5 and −4.00 D were recorded in 10 young subjects. Accommodative response, peak velocity, and time constant of accommodation and pupil constriction were assessed. The measurements were evaluated in all the participants with distance-single vision CLs and with the three multifocal CLs. The monocular measurements were performed in a random sequence for each participant. All parameters were measured with a Hartmann-Shack aberrometer (IRX-3; Imagine Eyes, Orsay, France). Results. Differences were not found in accommodation response for both accommodative stimuli studied between the single vision lens and the three different multifocal CLs (p > 0.05 for both stimuli). For the 2.5 D stimulus, significant differences were not found in peak velocity and time constant between the single vision lens and the three different multifocal CLs (p > 0.05 for all situations); in amplitude of pupil constriction, differences were only found for the situation with PureVision High Add, where the value was lower than the single vision lens (p = 0.015). For the 4.00 D stimulus, differences with single vision lens in peak of velocity and time constant were only found with PureVision Low Add, where the peak velocity value was higher and the time constant was lower (p = 0.024 and p = 0.032 for peak of velocity and time constant, respectively); for amplitude of pupil constriction differences were not found (p > 0.05). Conclusions. Data obtained in this pilot study suggest that in young observers, the multifocal CLs studied do not induce large changes in accommodative system compared with the single vision lens.

Optical power distribution of refractive and aspheric multifocal contact lenses: Effect of pupil size

PURPOSE To evaluate the power profile within the optic zone of different designs of multifocal contact lenses (CLs) and to analyze how the effect of pupil size could impact on their optical performance. METHODS The optical power distribution within the optic zones of multifocal CLs was measured by the Nimo TR1504 (LAMBDA-X, Belgium). The multifocal CLs under study were the Acuvue Bifocal, the Acuvue Oasys for Presbyopia, the PureVision Multifocal and the PureVision 2 for Presbyopia. Each design was considered in all their available addition powers. All lenses had a nominal power of -3.0D. At the same time, three lenses of each model were considered and five consecutive readings of each lens were performed. RESULTS The results show that the PureVision Multifocal and the PureVision 2 for Presbyopia have aspheric power profiles. Both designs showed aspheric center-near designs with a smoother progression of the optical power in the PureVision 2 for Presbyopia. The Acuvue Bifocal and the Acuvue Oasys for Presbyopia are shown to have concentric alternating near and far zones. Apart from the refractive rings, the Acuvue Oasys for Presbyopia showed an increase in negative (or less positive) values toward the periphery of the lens. CONCLUSIONS Besides the refraction, the knowledge of the power profiles of multifocal CLs and the effect of pupil size on the optical distribution of these lenses could be crucial to understand the performance of these designs when they are fitted.

Changes in accommodation and ocular aberration with simultaneous vision multifocal contact lenses.

Objective: The aim of this study was to evaluate ocular aberration changes through different simultaneous vision multifocal contact lenses (CLs). Methods: Eighteen young-adult subjects with a mean age of 29.8±2.11 years took part. Changes in accommodative response, spherical aberration ( ), horizontal coma ( ), vertical coma ( ), and root mean square (RMS) of higher-order aberrations (HOAs, third to sixth orders) were evaluated. Measurements were obtained with a distance-single vision CL and 2 aspheric multifocal CLs of simultaneous focus center-near design (PureVision Low Add and PureVision High Add) for 2 accommodative stimuli (−2.50 and −4.00 D). All measurements were performed monocularly with a Hartmann–Shack aberrometer (IRX-3; Imagine Eyes, Orsay, France). Results: No statistically significant differences were found in accommodative responses to −2.50- and −4.00-D stimuli between the single vision CL and the 2 multifocal CLs. Spherical aberration was found to decrease and become more negative with accommodation for both stimuli with all three CLs. Horizontal coma decreased significantly with accommodation (−2.5- and −4.00-D stimuli) for the distance-single vision CLs (P=0.002 and P=0.003). No differences were found in vertical coma Zernike coefficients. The RMS of HOAs was found to decrease only with the single vision CLs for both stimuli (P<0.01). Conclusions: Data obtained in this study suggest that in young subjects, the multifocal CLs studied do not induce large changes in accommodative response compared with the distance-single vision CLs. Spherical aberration reduced significantly with accommodation.

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.