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183 result(s) for "Auffarth, Gerd U."
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Enhancing the Intermediate Vision of Monofocal Intraocular Lenses Using a Higher Order Aspheric Optic
PURPOSE: To describe and evaluate a new monofocal intraocular lens (IOL) designed to improve intermediate vision using a unique refractive technology. METHODS: The new monofocal lens is based on a higher order aspheric optic and is designed to improve intermediate vision. Simulated visual acuity from far to −2.00 diopters (D) was calculated using optical bench data. The effect of corneal higher order aberrations (HOAs) on simulated visual acuity, pupil size, and decentration was assessed using realistic computer eye models. The susceptibility to photic phenomena was evaluated by measuring preclinically the intensity of the light distribution in the retinal plane. The new lens design was compared to a standard aspheric monofocal IOL that shares the same platform, material, and primary spherical aberration as the new design. RESULTS: Simulated defocus curves showed increased simulated visual acuity in the intermediate range compared to a standard aspheric monofocal IOL with comparable distance vision, independently of the pupil size and corneal HOAs. At −1.50 D, the new IOL design provided a gain of approximately 0.1 logMAR, whereas at distance, the difference was less than 0.05 logMAR. The tolerance to decentration was also similar in both designs. Finally, experimental results indicate that the susceptibility to photic phenomena with the new lens design was similar to that of a standard aspheric monofocal IOL. CONCLUSIONS: Preclinical data showed that the new lens design improves intermediate vision while maintaining comparable distance image quality and keeping the same photic phenomena profile as a standard aspheric monofocal IOL. [J Refract Surg. 2020;36(8):520–527.]
Chromatic aberration and spectral dependency of extended-range-of-vision intraocular lens technology
This study compared the optical quality and chromatic performance of refractive-diffractive intraocular lenses (IOLs) that are designed to extend the range of vision of pseudophakic patients and alter chromatic aberration. Five IOLs were evaluated, Tecnis Synergy and Triumf POD L GF, both intended to compensate for eye's chromatism, as well as Acriva Trinova Pro C—a lens that increases chromatic aberration, and AT Lisa Tri and AcrySof IQ PanOptix. An optical setup composed of a corneal model inducing monochromatic and chromatic aberrations and incorporating various spectral conditions was employed. The two chromatic-aberration correcting IOLs demonstrated the lowest far-focus dispersion, but it was negative only, with the Synergy indicating its ability to reduce eye’s chromatic aberration. Although the Trinova increased far-point chromatism, it was close to the level of the PanOptix, but higher than that of the AT Lisa. All the studied models demonstrated varying optical quality in response to light color. Still, the strongest spectral dependency was associated with achromatizing technology. Therefore, chromatic aberration and wavelength dependency should be considered in IOL optimization and predicting visual function, particularly in non-white spectral conditions.
Evaluation of Clareon Vivity and PureSee intraocular lenses: optical quality, depth of focus and misalignment effects
Extended depth of focus (EDoF) intraocular lenses allow cataract and refractive-lens-exchange patients to have improved vision at an intermediate distance. Two EDoF lenses, Clareon Vivity and Tecnis PureSee, were evaluated for optical quality using the OptiSpheric IOL Pro2 according to ISO 11979-2 guidelines and measured using Modulation Transfer Function (MTF) and 1951 USAF resolution test chart at 3.0- and 4.5-mm apertures. The IOLs’ tolerance to 0.50 mm decentration and a 5° tilt were tested. The unwanted visual effects were compared using their light distribution at 4.5 mm aperture beyond a polychromatic point spread function center. The two models demonstrated comparable optical qualities at intermediate and far focuses; the predicted visual acuities for the Vivity and PureSee were respectively − 0.04 versus − 0.05logMAR at 0 diopter and 0.05 versus 0.07logMAR at − 1.50 diopters of defocus. Increasing pupil size decreased both lenses’ optical quality. While decentration decreased the optical quality of both models, tilt had less of an effect. Both were similar in introducing minimal unwanted side effects through visualizing a halo pattern. The results indicate that these lenses offer a good option for patients interested in EDoF lenses and future clinical studies should contribute further insight into their performance and side effects.
Vertical implantable collamer lens as a novel method to increase rotational stability
We investigated the vertical implantation of a toric implantable collamer lens (ICL) and compared the rotational stability with that of horizontal implantation. This matched comparative study retrospectively reviewed and analyzed data from patients who underwent ICL implantation from 2003-2022 by 1:1 matching vertical and horizontal (V and H toric groups, respectively) implantation patients according to preoperative astigmatism, spherical equivalent, sulcus-to-sulcus, anterior chamber depth, and ICL size. Visual acuity, manifest refraction, vaulting, and rotation were measured 3 months postoperatively. We included 646 eyes (323 each in the V and H toric groups). No statistically significant difference was observed between groups in postoperative visual acuity, refractive error, and astigmatism. Vaulting was lower in the V toric group. (P < 0.001). The mean lens rotation in the V toric group was less than that in the H toric group (1.11 ± 2.84° versus 3.02 ± 10.34°, P = 0.001). The proportion of eyes in the V and H toric groups showing ≥10° of rotation was 2.5% (8 eyes) and 6.5% (21 eyes), respectively (P = 0.014). Despite repositioning from rotation, three (0.9%) and eight (2.5%) eyes required removal owing to lens re-rotation in the V and H toric groups, respectively. Toric ICL vertical implantation showed good rotational stability, and appropriate visual acuity correction results with relatively low vaulting. This procedure therefore presents an effective novel method that could replace horizontal toric ICL implantation.
Visual function comparison of a non-diffractive extended depth-of-focus and an enhanced monofocal intraocular lens sharing the same platform
This study compared the clinical outcomes and optical characteristics of the TECNIS Eyhance (EH; Johnson & Johnson Vision, Santa Ana, CA, USA) enhanced monofocal and the TECNIS PureSee (PS; Johnson & Johnson Vision) non-diffractive extended-depth-of-focus intraocular lenses (IOLs) sharing the same platform. In this retrospective analysis of real-world data, 69 eyes from 49 patients (EH: 35 eyes; PS: 34 eyes) were evaluated for visual acuity (VA) at distance, intermediate, and near ranges, alongside monocular defocus curves at 3-months postoperatively. To ensure a fair comparison and optimize intermediate vision, a consistent postoperative target refraction of -0.20 to -0.30 D was set for all eyes. Generalized estimating equations accounted for intra-subject correlations. At 3-months, both IOLs provided comparable excellent distance vision and refractive predictability without significant intergroup differences in prediction error ( p = .846) or mean absolute error ( p = .833). However, the PS IOL delivered significantly better uncorrected intermediate (0.16 vs. 0.23 logMAR; p < .001) and near VA (0.32 vs. 0.40 logMAR; p < .001) than the EH IOL. In conclusion, while both IOLs offer excellent distance vision and refractive stability, the non-diffractive PS IOL provides superior intermediate and near visual performance compared to the EH IOL.
Ray propagation imaging and optical quality evaluation of different intraocular lens models
Ray propagation visualization and optical performance analysis of four different intraocular lenses (IOLs). In this laboratory study, four IOLs with different optical designs were assessed: a monofocal AcrySof IQ SN60WF [Alcon], a diffractive-refractive bifocal AcrySof IQ Restor SN6AD1 [Alcon], a diffractive trifocal AcrySof IQ PanOptix TFNT00 [Alcon], and a diffractive extended-depth-of-focus (EDOF) Symfony ZXR00 [Johnson&Johnson]. An experimental set-up with a water bath containing 0.01% fluorescein solution and monochromatic green laser light (532 nm) was used to visualize the propagation of light rays. Also, the optical performance of the IOLs was evaluated by measuring the modulation transfer function (MTF) values at a pupil sizes of 3.0 and 4.5 mm on the optical bench OptiSpheric® IOL PRO II (Trioptics GmbH, Germany). Both the diffractive-refractive bifocal IOL and the EDOF IOL showed two defined foci for distance and near vision. In the diffractive trifocal IOL, three distinct foci for distance, intermediate, and near vision could be visualized. The ray propagation visualization technique allows a qualitative assessment and comparison of light energy distribution between different IOL models. The measured Through-Focus Response (TFR) quantitatively confirmed the evaluated ray propagation behavior.
Experimental analysis of recommended corneal incision sizes in cataract surgery using 13 intraocular lens injector systems
Smaller corneal incisions in cataract surgery are linked with a better visual outcome and less frequent postoperative endophthalmitis. The insertion of intraocular lens (IOL) injector systems into the anterior chamber of the eye to implant an IOL is associated with incision enlargement (IE) impeding these positive effects. The aim of this study was to compare manufacturers’ recommended incision sizes (IS) of 13 different intraocular lens injector systems in regard of intraoperative IE and postoperative IS. In total, 499 corneal incisions in ex vivo porcine eyes were analyzed. The preoperative ISs depended on the recommended IS of the examined injector system. The IS was measured right before and after IOL injector insertion with an incision gauge set. There was intraoperative IE in 87% of the incisions with a mean IE of 0.26 ± 0.18 mm. IE was often significantly larger in small IS compared to larger IS concerning an injector system (P < 0.05). Five injector systems needed to have a significantly larger IS than the manufacturers’ recommended IS with an average difference of 0.3 mm when applying study criteria (P < 0.05). Thus, the present study shows that IS recommendations require to be critically analyzed by ophthalmic surgeons to enable evidence-based practice.
Comparison of Five Presbyopia-Correcting Intraocular Lenses: Optical-Bench Assessment with Visual-Quality Simulation
Presbyopia correction through implantation of a trifocal intraocular lens (IOL) is a modality offered to both cataract and refractive-lens exchange patients. To maximize postoperative satisfaction, IOL selection needs to be made based on patients’ requirements aligned with the available technology. Five Trifocal IOLs were assessed in this study, and their differentiating features were identified: Triumf POD L GF, AT Lisa Tri, Tecnis Synergy, AcrySof IQ PanOptix, and Acriva Trinova Pro C. The optical quality was assessed using the modulation-transfer-function principle. Simulated defocus curves were derived from a non-linear formula. Far-focus simulated visual acuity (simVA) was 0.03 logMAR or better for all the studied IOLs, showing minimal differences. However, each IOL’s intermediate focus position differed across a range from 61 cm to 80 cm; and for the near focus, it was 36 cm to 44 cm. Triumf demonstrated improved intermediate point at the expense of the near focus resulting in a lower predicted near VA. PanOptix exhibited the shortest range of vision without a clear distinction between intermediate and near-point. The remaining lenses presented three foci of comparable optical quality and, thus, simVA performance. Each model, however, revealed a different aperture-change response. Trinova function improved at intermediate but was worse at near for larger pupils. The opposite was observed for AT Lisa. Synergy’s optical quality change was predominantly associated with lower pupil diameter. In conclusion, the trifocal IOLs can be differentiated according to their secondary-foci position, light-energy distribution, and pupil-size-related behavior. The observed differences may translate directly into a clinical effect showing that the trifocal IOLs vary in their ability to deliver optimal vision at different distances, with some providing improved intermediate while others favor reading distance. The knowledge gained through this objective testing can support IOL selection, postoperative patient counselling and increase the chance of spectacle independence after surgery.
Aesthetics of iris reconstruction with a custom-made artificial iris prosthesis
Patients with large iris defects not only suffer from functional disadvantages but also from aesthetic limitations. The aim of this study was to evaluate the aesthetic outcome of iris reconstruction using an artificial iris (AI). In this study, 82 eyes of 79 consecutive patients with mostly traumatic partial or total aniridia that underwent iris reconstruction surgery using a custom-made silicone AI (HumanOptics, Erlangen, Germany). Pre- and postoperative photographs of 66 patients were analysed subjectively and objectively. Subjective evaluation was based questionnaires. Objective evaluation included measurement of pupil centration and iris colour analysis. Averaged hues from iris areas were transferred to numerical values using the LAB-colour-system. Single parameters and overall difference value (ΔE) were compared between AI and remaining iris (RI), as well as AI and fellow eye iris (FI). Patients, eye doctors and laymen rated the overall aesthetic outcome with 8.9 ±1.4, 7.7 ±1.1 and 7.3 ±1.1 out of 10 points, respectively. Mean AI decentration was 0.35 ±0.24 mm. Better pupil centration correlated with a higher overall score for aesthetic outcome (p<0.05). The AI was on average 4.65 ±10 points brighter than RI and FI. Aniridia treatment using a custom-made artificial iris prosthesis offers a good aesthetic outcome. Pupil centration was a key factor that correlated with the amount of aesthetic satisfaction. The AI was on average slightly brighter than the RI and FI.
Quantitative evaluation of microvacuole formation in five intraocular lens models made of different hydrophobic materials
In this laboratory study, we assessed the resistance to microvacuole (glistening) formation in hydrophobic intraocular lenses (IOLs). Glistenings were induced in five lenses each of five different hydrophobic acrylic IOL models, using an established in vitro laboratory model: 800C (Rayner, Worthing, UK), AcrySof SN60WF (Alcon, Fort Worth, USA), Tecnis ZCB00 (Johnson & Johnson Vision, Santa Ana, USA), Vivinex XY1 (Hoya, Tokyo, Japan) and CT Lucia 611P (Zeiss, Oberkochen, Germany). We evaluated the number of microvacuoles per square millimeter (MV/mm 2 ) in the central part of each IOL. Results were analyzed statistically, and mean glistening numbers were ranked, with the highest in the SN60WF which had 66.0 (±45.5) MVs/mm, followed by the 611P with 30.7 (±8.4) MVs/mm 2 . The 800C and XY1 showed comparable values of 2.0 (±3.6) and 2.7 (±2.4) MVs/mm 2 , respectively. ZCB00 had the lowest number with 0.9 (±0.6) MVs/mm 2 . This study shows that the resistance to glistening formation differs depending on the hydrophobic acrylic copolymer composition of the IOL material. Some IOLs from current clinical use are still prone to develop glistenings whereas others, including the ZCB00, 800C and XY1 show high resistance to microvacuole formation.