Diffractive Bifocal Intraocular Lens Research Articles

Retinal Image Quality Through an Operating Microscope With Wavefront Shaping Extended Depth of Focus Intraocular Lens in Model Eye

To compare the quality of images of gratings placed in a model eye viewed through an extended depth of focus (EDoF) intraocular lens (IOL) to that of diffractive bifocal IOL or monofocal IOL. Experimental laboratory investigation. Nondiffractive wavefront shaping EDoF (CNAET0, Alcon Laboratories), echelette-designed EDoF (ZXR00V, Johnson & Johnson Vision), diffractive bifocal IOL with low power addition (SV25T, Alcon Laboratories), or monofocal IOL (CNA0T0, Alcon Laboratories) was placed in a fluid-filled model eye. A United States Air Force Resolution Grating Target was glued to the posterior surface of the model eye and viewed through a flat or a wide-angle contact lens. The contrast of the gratings viewed through the EDoF or multifocal IOLs was compared to that through the monofocal IOL. A wavefront analyzer was used to measure the spherical power of the central 4.5 mm optics of the EDoF, multifocal, and monofocal IOLs. The distribution of the dioptric power and the dioptric power map were compared. The gratings observed through the flat contact lens with CNAET0, ZXR00V, or SV25T were slightly blurred when viewed through the multifocal optics. The blurred area was in the circumferential area of CNAET0, the central area of SV25T, and the peripheral area of ZXR00V. The mean contrast was 0.258 ± 0.020 for CNAET0, 0.227 ± 0.025 for ZXR00V, and 0.221 ± 0.020 for SV25T for the 16.0 cyc/mm grating. The contrast was significantly lower for ZXR00V (P = .004) and SV25T (P = .004) than 0.303 ± 0.015 for CNA0T0 but the differences were not significant for CNAET0. For the wide-angle contact lens, the contrast for CNAET0 was 0.182 ± 0.009, for ZXR00V was 0.162 ± 0.011, and for SV25T was 0.163 ± 0.007 for the 16.0 cyc/mm grating, and none was significantly different from 0.188 ± 0.012 for CNA0T0. The dioptric variations of CNAET0 indicated a ring-shaped area of higher power corresponding to the circumferential blurred zone observed through the flat contact lens. The wavefront shaping and echelette-designed EDoF-IOLs reduce the contrast of the grating more than the monofocal IOL when viewed through the flat contact lens. The degree of reduction depended on the design of the extended-focus optics. The difference was less through the wide-angle contact lens.

Comparison of visual performance between diffractive bifocal and diffractive trifocal intraocular lenses

To evaluate the visual performance of a diffractive bifocal intraocular lens (IOL) with + 4.0 D near addition (ZMB00) and a diffractive trifocal IOL with + 2.17 D and + 3.25 D near addition (AcrySof IQ PanOptix TFNT00), we investigated the 10-week postoperative parameters after cataract surgery in which ZMB00 or TFNT00 lenses were implanted bilaterally from 2011 to 2020 (with a 3-month interval between implantation of the right and left lenses). The study included 1448 eyes of 724 patients. The diffractive bifocal group comprised 1326 eyes of 663 patients (aged 67.0 ± 7.8 years; females/males, 518/145), and the diffractive trifocal group comprised 122 eyes of 61 patients (aged 66.6 ± 7.3 years; females/males, 35/26). A linear mixed-effects model using data for both eyes, with strict adjustments for sex, age, subjective refraction spherical equivalent, subjective refraction cylinder, corneal astigmatism, axial length, corneal higher-order aberrations, and pupil diameter, ensured statistical validity. Uncorrected near visual acuity and higher-order aberrations (ocular/internal, scaled to a pupil size of 4 mm) (Wavefront_4mm_postoperative_Ocular/Internal_Spherical) were significantly better in the bifocal group (p < 0.00068, Wald test). Uncorrected intermediate visual acuity, contrast sensitivity (6.3/4.0/2.5/1.6/1.0/0.7 degrees), and contrast sensitivity with glare (4.0/1.6/1.0/0.7 degrees) were significantly better in the trifocal group (p < 0.00068, Wald test).

Characterization of diffractive bifocal intraocular lenses

Multifocal intraocular lenses incorporate a variety of design considerations, including dimensioning of the base monofocal shape and the diffraction grating. While studying three different lens models, we present a practical approach for mathematical modelling and evaluation of these geometries. Contrary to typical lens measurement methods, non-contact measurements were performed on the Alcon SN6AD1, HumanOptics MS 612 DAY and the AMO ZMA00 lenses using a confocal microscope. Subsequent data processing includes centering, tilting correction, filtering and an algorithmic decomposition into a conic and polynomial part and the diffraction grating. Lastly, evaluation of fitting parameters and grating shape is done to allow for inferences about further optical properties. Results and analysis show the confocal microscope to be a suitable imaging method for lens measurements. The processing of this data enables the reconstruction of the annular diffraction grating over the complete lens diameter. Apodization, near addition and diffraction efficiency characteristics are found utilizing the grating shape. Additionally, near-optical axis curvature, asphericity and higher order polynomials are identified qualitatively from the reconstruction of the monofocal base form. Derived properties also include the lens optical base and addition power. By making use of the surface geometries, as well as the lens’ material and thickness, a full lens model can be created for further studies. In summary, our analytical approach enables the insight to various intraocular lens design decisions. Furthermore, this procedure is suitable for lens model creation for research and simulation.

Comparative visual performance of diffractive bifocal and rotationally asymmetric refractive intraocular lenses

We compared the visual performance of a diffractive bifocal intraocular lens (IOL) with + 4.0 D near addition (ZMB00 [Johnson & Johnson Surgical Vision]) and a rotationally asymmetric refractive IOL with + 1.5 D near addition (LS-313 MF15 [Teleon Surgical BV]) 10 weeks after cataract patients’ last surgery for bilateral ZMB00 or LS-313 MF15 implantation between 2011 and 2020, with the lenses of each eye implanted within 3 months of each other. The ZMB00 and LS-313 MF15 groups comprised 1326 eyes of 663 patients (age: 67.0 ± 7.8 years; females/males, 518/145) and 448 eyes of 224 patients (73.6 ± 7.0 years; females/males, 125/99), respectively. A linear mixed-effects model using data for both eyes, with strict adjustments for sex, age, subjective refraction spherical equivalent, subjective refraction cylinder, corneal astigmatism, axial length, corneal higher-order aberrations, and pupil diameter, ensured statistical validity. Compared to LS-313 MF15, ZMB00 achieved significantly superior uncorrected near visual acuity, reduced higher-order aberrations (ocular/internal, scaled to a 4-mm pupil; Wavefront_4_post_Ocular_Total Higher-Order Aberration/Third/Fourth/Trefoil/Coma/Tetrafoil/Spherical, Wavefront_4_post_Internal_Astigmatism/Total Higher-Order Aberration/Third/Trefoil/Coma/Tetrafoil/Spherical), and superior distance and near spectacle independence (p < 0.00068, Wald test). Contrast sensitivity, measured without (visual angle of the test target: 6.3°/4.0°/2.5°/1.6°/1.0°/0.7°) or with glare (4.0°/2.5°/1.6°/1.0°/0.7°), was significantly better in the LS-313 MF15 than the ZMB00 group (p < 0.00068, Wald test).

Stereopsis and visual acuity: Bilateral trifocal versus blended extended depth of focus and diffractive bifocal intraocular lenses.

To compare stereopsis and visual acuity (VA) between bilateral implantation of trifocal intraocular lenses (IOL) and blended implantation of an extended depth of focus (EDOF) IOL with a bifocal IOL. This is a non-randomized, prospective comparative study included 74 eyes of 37 patients who underwent phacoemulsification and bilateral implantation of AT LISA tri 839MP IOL (bilateral group; 21 patients) or blended implantation of Tecnis Symfony ZXR00 and Tecnis ZLB00 IOL (blended group; 16 patients). The primary outcomes were stereoacuity and binocular VA. The secondary outcomes were visual defocus curve, quality of life, and patient satisfaction. Follow-up was performed 3 months after the surgery. The mean near stereoacuity was 49.76 ± 22.67 and 120.63 ± 90.94 seconds of arc (arcsec) in the bilateral and blended groups, respectively (P < 0.001). Near stereoacuity was positively correlated with VA difference of two eyes (r = 0.896, P < 0.001). The mean binocular uncorrected visual acuity at 40 cm, 80 cm, 5 m, and corrected distance visual acuity at 5 m of the bilateral and blended groups was not statistically significant different. The bilateral group had better VA at a vergence from -2.5 to -4.0 D. Both groups obtained high quality of life and patient satisfaction scores. The bilateral and blended groups achieved good binocular VA, quality of life, and high patient satisfaction. However, the near stereoacuity of the blended group was worse.

Visual Outcomes and Optical Quality of Accommodative, Multifocal, Extended Depth-of-Focus, and Monofocal Intraocular Lenses in Presbyopia-Correcting Cataract Surgery

A bayesian network meta-analysis (NMA) can help compare the various types of multifocal and monofocal intraocular lenses (IOLs) used in clinical practice. To compare outcomes of presbyopia-correcting IOLs frequently recommended in clinical practice through a bayesian NMA based on a systematic review. Medline (PubMed) and the Cochrane Central Register of Controlled Trials (CENTRAL) were searched on May 15, 2021, from inception. Based on the research question, randomized clinical trials assessing multifocal IOLs in patients who underwent bilateral cataract extraction were searched. Nonrandomized studies, studies in patients with unilateral or contralateral cataract extractions, duplicated studies, conference abstracts, and nonpeer-reviewed articles were excluded. Descriptive statistics and outcomes were extracted. The NMA was conducted to compare different types of IOLs. The mean differences for continuous variables, odds ratios for binary variables, 95% credible intervals (CrIs), and ranks of interventions were estimated. The outcomes examined included binocular visual acuities by distance and optical quality, including glare, halos, and spectacle independence. This NMA included 27 studies comprising 2605 patients. For uncorrected near visual acuity, trifocal IOLs (mean difference, -0.32 [95% CrI, -0.46 to -0.19]) and old bifocal diffractive IOLs (mean difference, -0.33 [95% CrI, -0.50 to -0.14]) afforded better visual acuity than monofocal IOLs. Regarding uncorrected intermediate visual acuity, extended depth-of-focus IOLs provided better visual acuity than monofocal IOLs. However, there were no differences between extended depth-of-focus and trifocal diffractive IOLs in pairwise comparisons. For uncorrected distant visual acuity, all multifocal IOLs were comparable with monofocal IOLs. There were no statistical differences between multifocal and monofocal IOLs regarding contrast sensitivity, glare, or halos. For patients considering a multifocal IOL due to presbyopia, bilateral implantation of a trifocal IOL might be an optimal option for patients without compromising distant visual acuity.

Belin/Ambrósio Enhanced Ectasia Display in cataract surgery and relation to final visual acuity

Objective To analyze and describe the coefficients found on maximum Ambrósio Relational Thickness-Maximum (ART-Max) and Belin/Ambrósio Enhanced Ectasia Display total deviation (BAD-D) in eyes with normal corneal topography subjected to cataract surgery with premium intraocular lens implantation and correlated these data with final visual acuity. Methods ART-Max and BAD-D data from 103 eyes of patients subjected to implantation of diffractive bifocal intraocular lens, with normal corneal topography who achieved visual acuity of 20/20 or 20/25 without correction after cataract [...]

Comparative Analysis of the Clinical Outcomes of Mix-and-Match Implantation of an Extended Depth-of-Focus and a Diffractive Bifocal Intraocular Lens.

To evaluate and compare the clinical outcomes of the extended depth-of-focus intraocular lens (EDOF-IOL) and the diffractive bifocal IOL. Fifty-six eyes of 28 patients underwent cataract surgery with implantation of an EDOF-IOL (TECNIS Symfony, ZXR00) in their dominant eye and a diffractive bifocal IOL (+3.25 D add TECNIS ZLB00) in their nondominant eye. Monocular and binocular uncorrected distance, intermediate and near visual acuity, defocus curves, contrast sensitivity, patient satisfaction score (0-5), and spectacle dependence at near vision were evaluated at 3 months after the surgery. Postoperative binocular uncorrected distant visual acuity was 0.009±0.031 logMAR, uncorrected intermediate visual acuity was 0.090±0.158 logMAR, and uncorrected near visual acuity was 0.099±0.068 logMAR. The monocular defocus curve demonstrated better performance at intermediate distance in eyes with an EDOF-IOL and better performance at near distance in eyes with a diffractive bifocal IOL. An EDOF-IOL exhibited better outcomes in contrast sensitivity compared with a diffractive bifocal IOL. Three patients (10.7%) required glasses for near vision. Mix-and-match implantation of a diffractive bifocal IOL with an EDOF-IOL provides an excellent range of vision, and high levels of contrast sensitivity and patient satisfaction.

Cases of replacing diffractive bifocal intraocular lens with extended depth of focus intraocular lens due to waxy vision.

PurposeTo investigate the postoperative course of patients who explanted a diffractive bifocal intraocular lens (IOL) due to waxy vision and implanted with an extended depth of focus IOL.MethodsThis study evaluated 29 eyes of 25 patients who underwent diffractive bifocal IOL explantation followed by TECNIS Symfony® implantation because of dissatisfaction due to waxy vision at the Takabatake West Eye Clinic between January 2018 and November 2019. The indication criteria for this surgery were patients with uncorrected distance visual acuity of 0.05 logMAR or better, without eye diseases that may affect visual function, and no dissatisfactions about photic phenomena. We investigated patient demographics, uncorrected and corrected visual acuity, manifest refraction, contrast sensitivity, subjective symptoms, time to IOL explantation, explanted IOL type, and spectacle independence.ResultsThe time to the IOL exchange after the initial IOL implantation was 55.3 ± 50.4 days (range: 14–196 days). The logMAR corrected distance visual acuity before and after IOL exchange were −0.13 ± 0.06 and −0.14 ± 0.06, respectively (p = 0.273). After IOL exchange surgery, the area under log contrast sensitivity function increased significantly from 1.07 ± 0.12 to 1.21 ± 0.12 (p < 0.001), and the waxy vision symptoms improved. The spectacle independence rate at the last visit was 88.0%.ConclusionFor patients who complain of waxy vision despite good visual acuity after diffractive bifocal IOL implantation, exchange to extended depth of focus IOL was considered one of the useful surgical options.

Visual Performance Following Bilateral Implantation of Refractive Rotationally Asymmetric Bifocal Intraocular Lens (LS-313 MF30) or Apodized Diffractive Bifocal Intraocular Lens (ReSTOR SN6AD1).

PurposeThis study compared the clinical outcomes after cataract surgery with implantation of refractive rotationally asymmetric bifocal intraocular lens (IOL) (LS-313 MF30) and apodized diffractive bifocal IOL (ReSTOR SN6AD1).MethodsThis was a prospective, non-randomized, controlled study, where patients diagnosed with age-related cataracts were selected for phacoemulsification combined with bilateral IOL implantation. Based on the type of IOL voluntarily implanted, the patients were divided into two groups, ie, refractive and diffractive groups. In total, 30 cases (60 eyes) were in a refractive group, while 30 cases (60 eyes) were in diffractive group. Three months after surgery, we examined the uncorrected distance visual acuity (UDVA), uncorrected intermediate visual acuity (UIVA), uncorrected near visual acuity (UNVA), defocus curve, objective visual quality, and subjective questionnaire.ResultsThree months after surgery, the UIVA of the refractive group (0.18 ± 0.08) logMAR was better than that of the diffractive group (0.29 ± 0.16) logMAR (P < 0.05). No significant difference in UDVA and UNVA was noted between the two groups. For a 4mm pupil diameter, the intraocular and total eye aberration, higher-order aberration (HOA), coma, spherical aberration, and trefoil in the refractive group were significantly higher than those in diffractive group (P < 0.05). The intraocular modulation transfer function (MTF), intraocular strehl ratio (SR), total eye MTF, and total eye SR in the refractive group were lower than those in diffractive group (P < 0.05). No significant difference in glare incidence, spectacle independence rate, and patient satisfaction was observed between the two groups (P > 0.05). The halos incidence in the refractive group was lower than the diffractive group (P < 0.05).ConclusionBoth bifocal IOLs obtained satisfactory UDVA and UNVA, with higher patient satisfaction. Unlike the apodized diffractive bifocal IOL, the refractive rotationally asymmetric bifocal IOL yielded slightly better UIVA, lower halos incidence, whereas the apodized diffractive bifocal IOL showed a better objective visual quality.

Rainbow halos occur less following implantation of extended range of vision one-piece intraocular lenses vs diffractive bifocal intraocular lenses.

To evaluate clinical outcomes following implantation of an extended range of vision intraocular lens (IOL), the ZXR00, and a diffractive multifocal IOL with +2.75 diopters (D) add power, the ZKB00. Totally 30 patients who underwent either bilateral implantation of the ZXR00 IOL with intended emmetropia (ZXR00 emmetropia group: 20 eyes) and intended micromonovision (ZXR00 monovision group: 20 eyes), or bilateral implantation of the ZKB00 IOL with intended emmetropia (ZKB00 group: 20 eyes) were included in this study. Visual acuity at 4 m, 80, and 40 cm; and the types of halos (misty, fine, and rainbow) were analyzed at one and three months after surgery. There were no significant differences in distance visual acuity among the three groups. The mean uncorrected intermediate visual acuity was better in the ZXR00 emmetropia and monovision groups (0.02 logMAR and 0.02 logMAR, respectively) than in the ZKB00 group (0.14 logMAR). The mean uncorrected near visual acuity was worse in the ZXR00 emmetropia group (0.26 logMAR) than in the ZXR00 monovision and ZKB00 groups (0.12 logMAR and 0.10 logMAR, respectively). There was an increased incidence of rainbow halos in the ZKB00 group vs in either ZXR00 group (P=0.033). Implantation of the ZXR00 IOL with intended micromonovision provide superior visual acuity than implantation of the ZXR00 IOL with intended emmetropia. The ZXR00 IOLs tend to show a lower incidence of rainbow halos than did the ZKB00 IOL.

Comparison of Postoperative Outcomes of Trifocal Intraocular Lens with Enhanced Depth of Field and Diffractive Bifocal Intraocular Lens

Comparison of Postoperative Outcomes of Trifocal Intraocular Lens with Enhanced Depth of Field and Diffractive Bifocal Intraocular Lens

Monovision with a Bifocal Diffractive Multifocal Intraocular Lens in Presbyopic Patients: A Prospective, Observational Case Series

We report the visual outcomes and patient satisfaction after bilateral implantation of a bifocal diffractive intraocular lens with monovision. Prospective, observational case series. Twenty-one subjects underwent cataract surgery or refractive lens exchange with bilateral implantation of the ZMB00 intraocular lens, with the dominant eye and nondominant eye targeted for plano and-1.25 to-1.00 diopters, respectively. Postoperative assessments included visual acuity (VA) at various distances under photopic and mesopic conditions; defocus curve, contrast sensitivity, and stereopsis; and Visual Function Questionnaire-25 and supplementary questionnaire. Mean binocular uncorrected VA at distance, intermediate (67cm), and near (30cm) were-0.03 ± 0.06, 0.12 ± 0.18, and 0.11 ± 0.05, respectively. No eyes lost >1 line of corrected distance VA. Binocular intermediate VA was significantly better in the uncorrected condition (P= .004) whereas binocular distance VA was better in the distance-corrected condition (P= .014). Near VA was similar in both conditions (P > .05). Stereoacuity and contrast sensitivity were within normal limits. All subjects had a composite score of ≥90 for vision-targeted items in the National Eye Institute Visual Function Questionnaire-25. Halos, glare, and starbursts occurred in 52%, 29%, and 24% of subjects, respectively. All subjects reported a satisfaction score of ≥3.5 of 5 and required no spectacles postoperatively. No intraocular lens exchange was required. Monovision with bilateral bifocal multifocal intraocular lens was safe and provided satisfactory vision at various distances, with good stereopsis and contrast sensitivity. Complete spectacle independence and high satisfaction score were achieved. In comparisonwith bilateral emmetropic bifocal multifocal intraocularlens, it provided better vision at intermediate and atvery near distances without inducing more dysphotopsia.

Comparison of the Clinical Outcomes between Echelette Extended Range of Vision and Diffractive Bifocal Intraocular Lenses.

Purpose To compare the clinical outcomes of echelette extended range of vision (ERV) and diffractive bifocal intraocular lenses (IOLs). Methods This is a prospective, consecutive, nonrandomized clinical trial. Seventy-three eligible patients (109 eyes) received the implantation of echelette ERV IOL (Tecnis Symfony ZXR00) or diffractive bifocal IOL (Tecnis ZMB00). 1 week, 1 month, and 3 months after surgery, visual acuities at different distances were examined. At 3 months, defocus curves, contrast sensitivities (CSs) with and without glare, optic path difference (OPD) scans, and questionnaires were evaluated. Regression analyses were applied to discover influence factors on postoperative vision. Results ZXR00 showed better distance (P < 0.05) and intermediate (P < 0.001) visual acuities, while ZMB00 was better at distance-corrected near visual acuity (P < 0.001). Multivariate analyses indicated that worse intermediate (P < 0.001) and near vision (P=0.013) of ZMB00 might occur in patients with longer axial length. ZXR00 demonstrated smoother defocus curve and higher CSs. Superior modulation transfer function (MTF) and higher Strehl ratio (P < 0.05) were shown in ZXR00. In questionnaire evaluation, ZXR00 received better outcomes in self-reported vision, Visual Function-14 (VF-14) questionnaire, Quality of Vision (QoV) questionnaire, satisfaction, and recommendation grades. Spectacle dependence did not differ between ZXR00 and ZMB00 statistically. Conclusion ZXR00 proved to be remarkable in distance and intermediate vision, defocus curve smoothness, CSs, and visual comfort, while ZMB00 achieved better near vision. ZXR00 may attain better near vision if postoperative SE remains slightly negative. Patients with relatively longer axial length might receive less favorable intermediate and near vision after ZMB00 implantation. This trial is registered with ChiCTR-ONC-17011119.

Bilateral Implantation of a Single-Piece Bifocal Diffractive Intraocular Lens in Presbyopic Patients: A Prospective Case Series.

To report visual outcomes and quality after bilateral implantation of a single-piece diffractive multifocal intraocular lens (MIOL) with a bifocal design. Prospective, observational case series. All presbyopic subjects were implanted with the ZMB00 MIOL (Abbott Medical Optics) at the Hong Kong Sanatorium and Hospital. We evaluated the distance, intermediate, and near visual acuity (VA) under photopic and mesopic conditions; contrast sensitivity with and without glare under photopic and mesopic conditions; quality of vision; and rate of spectacle independence. A total of 36 subjects were included. No intraoperative complications developed. At the 6-month visit, the mean (± standard deviation) monocular uncorrected VAs at distance, intermediate, and near were 0.01 ± 0.12, 0.26 ± 0.17, and 0.09 ± 0.08, respectively. The respective mean binocular uncorrected VAs were -0.05 ± 0.09, 0.12 ± 0.13, and 0.04 ± 0.06. No eyes lost any corrected distance VA. The binocular contrast sensitivity was significantly better without glare than with glare under photopic and mesopic conditions (P < 0.05 for all spatial frequencies under both conditions). A total of 21 (58%) and 21 subjects (58%) reported halo and glare, respectively. Thirty subjects (83%) reported complete spectacle independence. Bilateral implantation of the bifocal MIOL in presbyopic patients with or without cataract was safe and resulted in satisfactory vision and a high rate of spectacle independence. Halos and glare were common.

Comparison of visual outcomes after bilateral implantation of a diffractive trifocal intraocular lens and blended implantation of an extended depth of focus intraocular lens with a diffractive bifocal intraocular lens.

PurposeThe purpose of this study was to compare the visual outcomes and subjective visual quality between bilateral implantation of a diffractive trifocal intraocular lens, Alcon Acrysof IQ® PanOptix® TNFT00 (group A), and blended implantation of an extended depth of focus lens, J&J Tecnis Symfony® ZXR00 with a diffractive bifocal intraocular lens, J&J Vision Tecnis® ZMB00 (group B).MethodsThis prospective, nonrandomized, consecutive, comparative study included the assessment of 40 eyes in 20 patients implanted with multifocal intraocular lens. Exclusion criteria were existence of any corneal, retina, or optic nerve disease, previous eye surgery, illiteracy, previous refractive surgery, high axial myopia, expected postoperative corneal astigmatism of >1.00 cylindrical diopter (D), and intraoperative or postoperative complications. Binocular visual acuity was tested in all cases. Ophthalmological evaluation included the measurement of uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), uncorrected near visual acuity (UNVA), and uncorrected intermediate visual acuity (UIVA), with the analysis of contrast sensitivity (CS), and visual defocus curve.ResultsPostoperative UDVA was 0.01 and −0.096 logMAR (p<0.01) in groups A and B, respectively; postoperative CDVA was −0.07 and −0.16 logMAR (p<0.01) in groups A and B, respectively; UIVA was 0.14 and 0.20 logMAR (p<0.01) in groups A and B, respectively; UNVA was −0.03 and 0.11 logMAR (p<0.01) in groups A and B, respectively. Under photopic conditions group B had better CS at low frequencies with and without glare.ConclusionBoth groups promoted good quality of vision for long, intermediate, and short distances. Group B exhibited a better performance for very short distances and for intermediate and long distances ≥−1.50 D of vergence. Group A exhibited a better performance for UIVA at 60 cm and for UNVA at 40 cm.

Expanding binocular depth of focus by combining monovision with diffractive bifocal intraocular lenses

To test the hypothesis that binocular depth of field can be expanded while retaining high-quality vision at intermediate distances by combining anisometropia (monovision) and simultaneous vision bifocals. School of Optometry, Indiana University, Bloomington, Indiana, USA. Prospective research study. A computational polychromatic model was used to simulate retinal images as seen through a pseudophakic eye with a diffractive bifocal for a range of target distances. Computationally blurred stimuli were presented dichoptically, simulating a binocular pseudophakic person with 1 emmetropic eye and 1 eye with myopia of 0.40 diopter (D), 0.80 D, or 1.20 D. Binocular visual acuity was measured for computationally blurred high-contrast Sloan letters. Ten subjects participated in this study. The emmetropic eye achieved best vision at infinity and near distance specified by the addition (add) power, while the myopic eye peak acuities were achieved at shorter viewing distances. Having 1 myopic bifocal eye had no effect on distance acuities. With a bifocal add of 2.20 D and 1.20 D of anisometropia, the binocular depth of focus was more than 3.00 D and provided binocular acuities of better than 20/20 throughout this range. For each target distance, the binocular acuities closely approached those of the better-focused eye. By careful selection of unilateral myopia and bilateral use of high-quality bifocal lenses, high intermediate distance acuities can exist with a large depth of field. This approach can improve intermediate vision and expand depth of field without compromising best achievable distance and near acuities. None of the authors has a financial or proprietary interest in any material or method mentioned.

Comparison of visual outcomes and subjective visual quality after bilateral implantation of a diffractive trifocal intraocular lens and blended implantation of apodized diffractive bifocal intraocular lenses

PurposeTo compare the visual acuity (VA) and quality of vision between bilateral implantation of a trifocal intraocular lens (IOL) and blended bifocal IOLs with an intermediate add in the dominant eye and a near add in the nondominant eye.Patients and methodsPatients with either trifocal or blended bifocal IOLs implanted were recruited after surgery. Subjects returned for a single diagnostic visit between 3 and 24 months after surgery. VA was tested at various distances, including low-contrast acuity and acuity at their preferred reading distance. A binocular defocus curve was obtained, and subjective visual function and quality of vision were evaluated.ResultsTwenty-five trifocal subjects and 30 blended bifocal subjects were enrolled. There were no significant differences in low-contrast acuity, preferred reading distance, or acuity at that reading distance. Binocular vision at 4 m, 60 cm, and 40 cm was not statistically significantly different. The trifocal provided statistically significantly better visual acuity (P<0.05) at vergences from −0.5 to −1.5 D (from 2 m to 67 cm viewing distance, P<0.05). There was no statistically significant difference in the near vision subscale scores of the 39-question National Eye Institute Visual Function Questionnaire or the overall scores of the Quality of Vision questionnaire, though significantly more trifocal subjects reported that the observed visual disturbances were “bothersome” (P<0.05).ConclusionBoth lens modalities provided subjects with excellent binocular near and distance vision, with similar low rates of visual disturbances and good reported functional vision. The trifocal IOL provided significantly better intermediate VA in the viewing distance range of 2 m to 67 cm, corresponding to viewing things such as a car dashboard or grocery shelf. VA was similar between groups at viewing distances from 60 to 40 cm, corresponding to computer or reading distance.

Comparison of the Visual Outcomes after Cataract Surgery with Implantation of a Bifocal and Trifocal Diffractive Intraocular Lens

Purpose: To evaluate and compare visual outcomes and optical quality after implantation of a bifocal (Acrysof ReSTOR SN6AD1) or trifocal (AT LISA tri 839MP) diffractive intraocular lens (IOL). Methods: Fifty-one eyes of 43 patients undergoing cataract surgery were enrolled and assigned to one of two groups: the trifocal group, comprising 24 eyes implanted with the trifocal diffractive IOL (AT LISA tri 839MP), and the bifocal group, comprising 27 eyes implanted with the bifocal diffractive IOL (Acrysof ReSTOR SN6AD1). Visual acuity (distant, intermediate, and near vision) and refractive postoperative outcomes were evaluated at one and three months postoperatively. Measurements of optical quality (using OQAS II), contrast sensitivity (using CGT-2000), automated visual field examination, and evaluation of defocus curve were performed three months postoperatively. Results: No statistically significant differences between the two groups were found in three-month postoperative distant and near (40 cm) visual acuities and optical quality. However, intermediate (63 cm, 80 cm, and 100 cm) visual acuities were significantly better in the trifocal group. Distant contrast sensitivity (5 m) under mesopic conditions was significantly better with the bifocal lens, whereas near contrast sensitivity (30 cm) under mesopic and scotopic conditions was significantly better with trifocal lens. There was no statistical difference between the groups under photopic conditions. In the defocus curve, the visual acuity was significantly better at intermediate distance in the trifocal group. Conclusions: Trifocal diffractive IOLs provide significantly better intermediate vision than bifocal IOLs, with equivalent postoperative levels of distant and near vision and ocular optical quality. Further, they provide better near contrast sensitivity under scotopic condition compared to diffractive bifocal IOLs. J Korean Ophthalmol Soc 2016;57(3):405-412

Halo and Through-Focus Performance of Four Diffractive Multifocal Intraocular Lenses.

To compare, as a function of pupil size, the through-focus performance and halo features of four diffractive intraocular lenses (IOLs). Three diffractive bifocal IOLs (ReSTOR +2.5 D SV25T0, Tecnis +2.75 D ZKB00, and AT LISA +3.75 D 809M) and a diffractive trifocal IOL (AT LISA tri +3.33 D, +1.66 D 839MP) were tested in vitro in a modified International Organization for Standardization eye model. The modulation transfer function (MTF) at the IOLs' foci was obtained with pupils ranging from 2.0 to 5.0 mm. Through-focus MTF curves (at 50 cycles/mm) were compared among all the IOLs. The halo formation and characteristics were obtained from image analysis. The multifocal IOLs studied in this work showed, at their foci, secondary out-of-focus images, which originate halos and whose characteristics depend on the lens design and pupil size. The smallest halo occurred for the distance focus of the SV25T0. The distance and near foci of the SV25T0 yielded, respectively, the best and lowest optical quality among the studied IOLs. The distance focus of the ZKB00, AT LISA, and AT LISA tri were of similar quality, but the near focus of the ZKB00 outperformed the near foci of the rest of the IOLs. The IOLs' optical performance gradually deteriorates as pupil increases. Differences in the design of the diffractive IOLs translate into differences in optical quality at their foci, through-focus performance, and halo features, which can offer further information to surgeons when selecting which IOL to implant.