Abstract

Whole-eye optical coherence tomography (OCT) imaging is a promising tool in ocular biometry for cataract surgery planning, glaucoma diagnostics and myopia progression studies. However, conventional OCT systems are set up to perform either anterior or posterior eye segment scans and cannot easily switch between the two scan configurations without adding or exchanging optical components to account for the refraction of the eye’s optics. Even in state-of-the-art whole-eye OCT systems, the scan configurations are pre-selected and cannot be dynamically reconfigured. In this work, we present the design, optimization and experimental validation of a reconfigurable and low-cost optical beam scanner based on three electro-tunable lenses, capable of non-mechanically controlling the beam position, angle and focus. We derive the analytical theory behind its control. We demonstrate its use in performing alternate anterior and posterior segment imaging by seamlessly switching between a telecentric focused beam scan to an angular collimated beam scan. We characterize the corresponding beam profiles and record whole-eye OCT images in a model eye and in an ex vivo rabbit eye, observing features comparable to those obtained with conventional anterior and posterior OCT scanners. The proposed beam scanner reduces the complexity and cost of other whole-eye scanners and is well suited for 2-D ocular biometry. Additionally, with the added versatility of seamless scan reconfiguration, its use can be easily expanded to other ophthalmic applications and beyond.

© 2023 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

Citation

Abstract

Purpose

To propose new methods for eye selection in presbyopic monovision corrections.

Methods

Twenty subjects with presbyopia performed two standard methods of binary eye dominance identification (sensory with +1.50 diopters [D ]and +0.50 D and sighting with “hole-in-the-card”) and two psychophysical methods of perceived visual quality: (1) the Preferential test, 26 natural images were judged with the near addition in one eye or in the other in a 2-interval forced-choice task, and the Eye Dominance Strength (EDS) defined as the proportion of trials where one monovision is preferred over the other; (2) the Multifocal Acceptance Score (MAS-2EV) test, the perceived quality of a natural images set (for 2 luminance levels and distances) was scored and EDS defined as the score difference between monovision in one eye or the other. Left-eye and right-eye dominance are indicated with negative and positive values, respectively. Tests were performed using a Simultaneous Vision Simulator, which allows rapid changes between corrections.

Results

Standard sensory and sighting dominances matched in only 55% of subjects. The Preferential EDS (ranging from −0.7 to +0.9) and MAS-2EV EDS (ranging from −0.6 to +0.4) were highly correlated. Selecting the eye for far in monovision with the MAS-2EV, sensory, or sighting tests would have resulted in 79%, 64%, and 43% success considering the Preferential test as the gold standard.

Conclusions

Tests based on perceptual preference allow selection of the preferred monovision correction and measurement of dominance strength.

Translational Relevance

The binocular visual simulator allows efficient implementation of eye preference tests for monovision in clinical use.

Citation

Barcala, X., Vinas, M., Ruiz, S., Hidalgo, F., Nankivil, D., Karkkainen, T., Gambra, E., Dorronsoro, D., & Marcos, S.; Multifocal contact lens vision simulated with a clinical binocular simulator. Contact Lens and Anterior Eye 2022, 45(6):101716. For more information, click here.

Abstract

Citation

Lago, C. M., de Castro, A., Benedí-García, C., Aissati, S., & Marcos, S. (2022).; Evaluating the effect of ocular aberrations on the simulated performance of a new refractive IOL design using adaptive optics. Biomedical Optics Express 2022, 13(12), 6682-6694. For more information, click here.

Abstract

Adaptive optics (AO) visual simulators are excellent platforms for non-invasive simulation visual performance with new intraocular lens (IOL) designs, in combination with a subject own ocular aberrations and brain. We measured the through focus visual acuity in subjects through a new refractive IOL physically inserted in a cuvette and projected onto the eye’s pupil, while aberrations were manipulated (corrected, or positive/negative spherical aberration added) using a deformable mirror (DM) in a custom-developed AO simulator. The IOL increased depth-of-focus (DOF) to 1.53 ± 0.21D, while maintaining high Visual Acuity (VA, -0.07 ± 0.05), averaged across subjects and conditions. Modifying the aberrations did not alter IOL performance on average.

© 2022 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

Citation

Barcala, X., Zaytouny, A., Rego-Lorca, D., Sanchez-Quiros, J., Sanchez-Jean, R., Martinez-de-la-Casa, J. M., Dorronsoro, C., & Marcos, S.; Visual simulations of presbyopic corrections through cataract opacification. Journal of Cataract & Refractive Surgery 2022, 10: 1097. For more information, click here.

Abstract

Patients can rank the perceived image quality through cataract up to high level of opacity and that the preoperative ranking of the corrections matches that performed postoperatively through transparent media.

Purpose

To study the viability of visual simulation of presbyopic correction in patients with cataract and the effect and impact of the cataract on the perceived visual quality of the different simulated presbyopic corrections preoperatively and postoperatively.

Setting

San Carlos Clinical Hospital, Madrid, Spain.

Design

Observational, noninterventional, pilot study, early feasibility of the device being studied.

Methods

Cataract patients were tested preoperatively (n = 24) and postoperatively (n = 15) after bilateral implantation of monofocal intraocular lenses (IOLs). The degree of cataract was evaluated objectively with the objective scatter index (OSI). Visual acuity (VA) and perceived visual quality of natural scene images (Multifocal Acceptance Score) were measured before and after cataract surgery at far (4 m), intermediate (64 cm) and near distance (40 cm) with 4 binocular presbyopic corrections (single vision, bifocal, monovision and modified-monovision) simulated with a binocular Simultaneous Vision simulator based on temporal multiplexing.

Results

VA was significantly correlated with OSI (r = −0.71, P < .0005), although the visual degradation at far for each correction was constant and not correlated with OSI. The visual benefit at near distance provided by the presbyopic correction was noticeable (23.3% ± 27.6% across corrections) for OSI <5. The individual perceptual scores were highly correlated preoperatively vs postoperatively (r = 0.64, P < .0005) for all corrections and distances.

Citation

Benedi-Garcia, C., Vinas, M., Lago, C. M., Aissati S., De Castro, A., Dorronsoro, C, and Marcos, S.; Optical and visual quality of real intraocular lenses physically projected on the patient’s eye. Biomed. Opt. Express 12, 6360-6374 (2021). For more information, click here.

Abstract

Visual simulators aim at evaluating vision with ophthalmic corrections prior to prescription or implantation of intraocular lenses (IOLs) in the patient’s eye. In the present study, we present the design, implementation, and validation of a new IOL-in-cuvette channel in an Adaptive Optics visual simulator, which provides an alternative channel for pre-operative simulation of vision with IOLs. The IOL is projected on the pupil’s plane of the subject by using a Rassow system. A second lens, the Rassow lens, compensates for an IOL of 20 D while other powers can be corrected with a Badal system within a 5 D range. The new channel was evaluated by through-focus (TF) optical quality in an artificial eye on bench, and by TF visual acuity in patients, with various IOL designs (monofocal, diffractive trifocal, and refractive extended depth of focus).

©2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

SimVis Gekko simulations vs clinical data in implanted patients

We incorporated real data from commercial lenses¹ obtained from literature in our visual simulator SimVis Gekko and measured defocus curves in presbyopic subjects. A very high correlation (>90%) was found between the curves of real patients implanted with the same lenses and the simulation.

ESCRS 2021 Talk

¹Sawides, Lucie, et al. “SimVis simulations of multifocal IOL designs based on public-literature data.” Optical Design and Engineering VIII. Vol. 11871. SPIE, 2021.

²Ribeiro, Filomena, and Tiago B. Ferreira. “Comparison of clinical outcomes of 3 trifocal IOLs.” Journal of Cataract & Refractive Surgery 46.9, 1247-1252 (2020).

³Gil, M.A., Varón, C., Cardona, G. et al. “Visual acuity and defocus curves with six multifocal intraocular lenses.” Int Ophthalmol 40, 393–401 (2020).

Citation

Sawides, L., de Castro, A., Lago, C. M., Barcala, X., Zaytouny, A., Marcos, S., & Dorronsoro, C.; SimVis simulations of multifocal IOL designs based on public-literature data. Optical Design and Engineering VIII (Vol. 11871, pp. 122-132). SPIE. (2021 Sept.). For more information, click here.

Abstract

As a large variety of intraocular lens (IOL) designs is commercially available in a growing market, selecting the best IOL for each patient has become a crucial task for a positive surgical outcome. Information about the measured or estimated performance of commercial lenses, as the through-focus modulation transfer function (TF-MTF) at a given frequency and pupil diameter, is routinely published. SimVis Gekko, a see-through simultaneous vision simulator based on temporal multiplexing, allows patients to experience the real world through different multifocal corrections prior to surgery. Implementing the maximum number of commercially available IOL designs into the portfolio of SimVis Gekko simulations is needed to provide a complete experience for the patients. We developed a new method to visually simulate IOL designs using temporal multiplexing, based only on publicly available information (mainly scientific literature or regulatory information), using the TF-MTF at 15cpd as input data to estimate the temporal coefficients that provide the best approximation to the real lens design. We validated the method with synthetic phase maps of equal area segmented bifocal and trifocal multifocal corrections for three pupil diameters of 3mm, 3.75mm and 4.5mm and applied it to three commercially available IOLs (trifocal or extended-depth-of-focus lenses). Through-focus visual acuity (TF-VA) curves were measured in seven patients using the SimVis simulations in the SimVis Gekko and matched, on average, the through-focus VA measurements in patients with implanted IOLs, reported in the scientific literature (on average logMAR RMS error=0.05, corresponding to less than 3 letters of visual acuity charts).

Keywords

Simultaneous vision; Temporal multiplexing; Visual simulations; MTF; Visual Strehl; Multifocal IOL designs; Through-focus optical quality

Citation

Marcos, S., Martinez-Enriquez, E., Vinas, M., de Castro, A., Dorronsoro, C., Pil Bang, S., Yoon, G., Artal, P.; Simulating Outcomes of Cataract Surgery: Important Advances in Ophthalmology. Annual Review of Biomedical Engineering 2021 23:1, 277-306. For more information, click here.

Abstract

As the human eye ages, the crystalline lens stiffens (presbyopia) and opacifies (cataract), requiring its replacement with an artificial lens [intraocular lens (IOL)]. Cataract surgery is the most frequently performed surgical procedure in the world. The increase in IOL designs has not been paralleled in practice by a sophistication in IOL selection methods, which rely on limited anatomical measurements of the eye and the surgeon’s interpretation of the patient’s needs and expectations. We propose that the future of IOL selection will be guided by 3D quantitative imaging of the crystalline lens to map lens opacities, anticipate IOL position, and develop fully customized eye models for ray-tracing-based IOL selection. Conversely, visual simulators (in which IOL designs are programmed in active elements) allow patients to experience prospective vision before surgery and to make more informed decisions about which IOL to choose. Quantitative imaging and optical and visual simulations of postsurgery outcomes will allow optimal treatments to be selected for a patient undergoing modern cataract surgery.

Keywords

intraocular lens; cataract surgery; anterior segment imaging; optical coherence tomography; visual simulation; adaptive optics