Standard Clinical Outcomes, Light Distortion, Stereopsis, and a Quality-of-Life Assessment of a New Binocular System of Complementary IOLs.

PURPOSE: To evaluate the visual outcome, light distortion index (LDI), and quality of life (QoL) of patients implanted with two complementary intraocular lenses (IOLs) to treat cataract and presbyopia. METHODS: Twenty-seven consecutive patients with cataract were treated with the implantation of the Artis Symbiose Mid (Mid) IOL (Cristalens Industrie) in the distance-dominant eye and the Artis Symbiose Plus (Plus) IOL (Cristalens Industrie) in the contralateral eye following phacoemulsification. The primary objective was to ascertain the monocular and binocular defocus curves. Secondary endpoints included uncorrected distance visual acuity, corrected distance visual acuity, uncorrected intermediate visual acuity, and distance-corrected intermediate visual acuity at 90 and 70 cm, uncorrected near visual acuity and distance-corrected visual acuity at 40 cm, contrast sensitivity, LDI with a halometer, stereopsis, and patients' QoL with the validated Visual Function Index (VF-14) questionnaire. These measurements were collected in two visits, at 4.14 ± 3.13 and 10.30 ± 3.14 months postoperatively. RESULTS: Statistically significant differences in the monocular defocus curves were found at the defocus steps of -1.00, -1.25, -1.50, -1.75, -2.50, -2.75, -3.00, -3.50 diopters and the -4.00 diopters (P < .050). The mean binocular defocus curve was 0 logMAR or better from the +0.50 to the -2.50 D defocus steps. Contrast sensitivity was within normal values. The LDI was 12.57 (6.61)% for the Mid eyes, 14.99 ± 5.70% for the Plus eyes, and 10.36 ± 4.42% binocularly. The patients' stereopsis was 40.0 (12.5) arc-seconds. The QoL score was 95.99 (7.14) at 10 months. CONCLUSIONS: The implantation of the Artis Symbiose IOLs was a safe and effective treatment for presbyopia compensation in patients with cataract. Both IOLs are complementary and may produce a binocular depth-of-field of 3.00 diopters over 0 logMAR when used together. [J Refract Surg. 2023;39(10):654-661.].

Total Depth of Focus of Five Premium Multifocal Intraocular Lenses.

PURPOSE: To compare the in vitro optical performance of five premium multifocal intraocular lenses (IOLs), including a single-valued metric that shows the total range of distances where a multifocal IOL generates an acceptable image quality. METHODS: Through-focus modulation transfer function (MTF) and the image of a United States Air Force target were obtained for a 3-mm pupil and a wavelength of 546 nm in five multifocal IOLs (Tecnis Symfony [Johnson & Johnson], FineVision Micro F [PhysIOL], Acrysof IQ PanOptix [Novartis], and Artis Symbiose Mid and Plus [Cristalens Industrie] multifocal IOLs). Total depth of focus (TDOF) is computed by adding the vergence intervals where the through-focus MTF at 50 cycles/mm is 0.15 or greater. RESULTS: Due to their different optical designs (bifocal, trifocal, or extended depth of focus), energy is distributed differently between far, intermediate, and near focus for each multifocal IOL. The light distribution of the Symbiose Mid and Plus multifocal IOLs was similar, concentrating the energy into far focus and the intermediate into near focus, but extending the intermediate focus more (Plus) or less (Mid) toward the near focus. TDOFs were: 1.58 diopters [D] (FineVision); 1.71 D (Tecnis Symfony); 1.73 D (Artis Symbiose Plus); 1.74 D (Artis Symbiose Mid); and 1.90 D (Acrysof IQ PanOptix). CONCLUSIONS: TDOFs were similar between multifocal IOLs with a maximum difference of 0.32 D and mean value of 1.73 D. The combination of the Symbiose Mid and Plus IOLs can theoretically provide a TDOF of 2.90 D in case one is implanted in one eye and the other in the fellow eye. [J Refract Surg. 2020;36(9):578-584.].

Factors Influencing Pseudo-Accommodation-The Difference between Subjectively Reported Range of Clear Focus and Objectively Measured Accommodation Range.

The key determinants of the range of clear focus in pre-presbyopes and their relative contributions to the difference between subjective range of focus and objective accommodation assessments have not been previously quantified. Fifty participants (aged 33.0 ± 6.4 years) underwent simultaneous monocular subjective (visual acuity measured with an electronic test-chart) and objective (dynamic accommodation measured with an Aston open-field aberrometer) defocus curve testing for lenses between +2.00 to -10.00 DS in +0.50 DS steps in a randomized order. Pupil diameter and ocular aberrations (converted to visual metrics normalized for pupil size) at each level of blur were measured. The difference between objective range over which the power of the crystalline lens changes and the subjective range of clear focus was quantified and the results modelled using pupil size, refractive error, tolerance to blur, and ocular aberrations. The subjective range of clear focus was principally accounted for by age (46.4%) and pupil size (19.3%). The objectively assessed accommodative range was also principally accounted for by age (27.6%) and pupil size (15.4%). Over one-quarter (26.0%) of the difference between objective accommodation and subjective range of clear focus was accounted for by age (14.0%) and spherical aberration at maximum accommodation (12.0%). There was no significant change in the objective accommodative response (F = 1.426, p = 0.229) or pupil size (F = 0.799, p = 0.554) of participants for levels of defocus above their amplitude of accommodation. Pre-presbyopes benefit from an increased subjective range of clear vision beyond their objective accommodation due in part to neural factors, resulting in a measured depth-of-focus of, on average, 1.0 D.

Accommodation and age-dependent eye model based on in vivo measurements / Modelo de ojo variable con la acomodación y la edad, basado en medidas in vivo

Purpose: To develop a flexible model of the average eye that incorporates changes with age and accommodation in all optical parameters, including entrance pupil diameter, under photopic, natural, environmental conditions. Methods: We collated retrospective in vivo measurements of all optical parameters, including entrance pupil diameter. Ray-tracing was used to calculate the wavefront aberrations of the eye model as a function of age, stimulus vergence and pupil diameter. These aberrations were used to calculate objective refraction using paraxial curvature matching. This was also done for several stimulus positions to calculate the accommodation response/stimulus curve. Results: The model predicts a hyperopic change in distance refraction as the eye ages (+0.22 D every 10 years) between 20 and 65 years. The slope of the accommodation response/stimulus curve was 0.72 for a 25 years-old subject, with little change between 20 and 45 years. A trend to a more negative value of primary spherical aberration as the eye accommodates is predicted for all ages (20-50 years). When accommodation is relaxed, a slight increase in primary spherical aberration (0.008μm every 10 years) between 20 and 65 years is predicted, for an age-dependent entrance pupil diameter ranging between 3.58 mm (20 years) and 3.05 mm (65 years). Results match reasonably well with studies performed in real eyes, except that spherical aberration is systematically slightly negative as compared with the practical data. Conclusions: The proposed eye model is able to predict changes in objective refraction and accommodation response. It has the potential to be a useful design and testing tool for devices (e.g. intraocular lenses or contact lenses) designed to correct the eye's optical errors

Objetivo: Desarrollar un modelo flexible de ojo medio que incorpore los cambios en función de la edad y la acomodación en todos los parámetros ópticos, incluyendo el diámetro de pupila de entrada, en condiciones ambientales fotópicas y naturales. Métodos: Recopilamos medidas retrospectivas in vivo de todos los parámetros ópticos, incluyendo el diámetro de pupila de entrada. Se usó un trazado de rayos para calcular las aberraciones de frente de onda del modelo ocular en función de la edad, vergencia de estímulo y diámetro de la pupila. Se utilizaron dichas aberraciones para calcular la refracción objetiva mediante el criterio de curvatura paraxial. Esto se realizó también para diversas posiciones del estímulo, para calcular la curva de respuesta acomodativa. Resultados: El modelo predice un cambio hipermetrópico en la refracción de lejos a medida que el ojo envejece (+ 0,22 D cada 10 años) entre los 20 y los 65 años. La pendiente de la curva de respuesta acomodativa fue de 0,72 para un sujeto de 25 años, con pocos cambios entre los 20 y los 45 años. Se predice una tendencia hacia un valor más negativo de la aberración esférica primaria a medida que el ojo acomoda, en todas las edades (de 20 a 50 años). Con la acomodación relajada, se predice un ligero incremento de la aberración esférica primaria (0,008 μm cada 10 años) entre los 20 y los 65 años, para un diámetro de pupila de entrada dependiente de la edad que oscila entre 3,58 mm (20 años) y 3,05mm (65 años). Los resultados concuerdan razonablemente bien con los estudios realizados en ojos reales, exceptuando que la aberración esférica es ligera y sistemáticamente menor en comparación a los datos experimentales. Conclusiones: El modelo de ojo propuesto es capaz de predecir los cambios de la refracción objetiva y la respuesta acomodativa. Tiene el potencial de ser una herramienta útil de diseño y prueba de elementos correctores (e.j.: lentes intraoculares o lentes de contacto) de los errores ópticos del ojo

Accommodation and age-dependent eye model based on in vivo measurements.

PURPOSE: To develop a flexible model of the average eye that incorporates changes with age and accommodation in all optical parameters, including entrance pupil diameter, under photopic, natural, environmental conditions. METHODS: We collated retrospective in vivo measurements of all optical parameters, including entrance pupil diameter. Ray-tracing was used to calculate the wavefront aberrations of the eye model as a function of age, stimulus vergence and pupil diameter. These aberrations were used to calculate objective refraction using paraxial curvature matching. This was also done for several stimulus positions to calculate the accommodation response/stimulus curve. RESULTS: The model predicts a hyperopic change in distance refraction as the eye ages (+0.22D every 10 years) between 20 and 65 years. The slope of the accommodation response/stimulus curve was 0.72 for a 25 years-old subject, with little change between 20 and 45 years. A trend to a more negative value of primary spherical aberration as the eye accommodates is predicted for all ages (20-50 years). When accommodation is relaxed, a slight increase in primary spherical aberration (0.008µm every 10 years) between 20 and 65 years is predicted, for an age-dependent entrance pupil diameter ranging between 3.58mm (20 years) and 3.05mm (65 years). Results match reasonably well with studies performed in real eyes, except that spherical aberration is systematically slightly negative as compared with the practical data. CONCLUSIONS: The proposed eye model is able to predict changes in objective refraction and accommodation response. It has the potential to be a useful design and testing tool for devices (e.g. intraocular lenses or contact lenses) designed to correct the eye's optical errors.

Impact of higher-order aberrations on depth-of-field.

It is well known that depth-of-focus (DOF) is influenced by optical factors (such as pupil size and monochromatic aberrations). However, neural factors such as blur sensitivity and defocus adaptation may play an important role on the extent of DOF. A series of experiments were conducted to study if optical or neural factors are most pertinent in explaining the variability of DOF across subjects. An adaptive optics system with a black and white target, a 3.8-mm artificial pupil, and a subjective criterion (based on objectionable blur) were used to measure depth of field ([DOFi]; DOF computed in the object space) in 11 participants, after at least 6 min of adaptation. This was done under three conditions: (a) with their own higher order aberrations (HOA); (b) after correction of their monochromatic HOA; and (c) after altering the HOA pattern for some participants to reflect the HOA pattern measured for a different participant. Natural DOFi and DOFi after HOA correction were positively correlated (R2 = 0.461), but a significant decrease in DOFi (21% on average) was found after HOA correction (p = 0.042). Effect of HOA on the intersubject variability of DOFi was 3.9 times smaller than the effect of the image neural processing. This study shows that DOFi depends on both optical and neural factors, but the latter seems to play a more important role than the former.