Standard Lens Research Articles

Distance and intermediate visual acuity after a new generation monofocal intraocular lens compared with the standard monofocal intraocular lens implantation

Purpose The aim of this study was to determine the effectiveness of a novel innovative monofocal intraocular lens (Tecnis Eyhance ICB00) compared with the standard monofocal lens (Tecnis-1-piece ZCB00) in terms of contrast sensitivity, postoperative refraction, intermediate visual acuity (VA), and uncorrected and best-corrected distance VA. Patients and methods This prospective comparative interventional clinical study was conducted from January 2021 to November 2021. It included 40 eyes of 20 patients who were divided into two groups, with 10 patients each. Candidates for bilateral cataract extraction by phacoemulsification were included in this study and underwent thorough preoperative examination and postoperative evaluation at 3 months after the second eye operation. The outcome measures included intermediate and distance VA, near add, contrast sensitivity, and incidence of photic phenomena, which was evaluated using a printed questionnaire. The binocular defocus curves were analyzed. Results The study included 20 patients (seven males and 13 females). Binocular and monocular uncorrected and corrected distance VAs were statistically similar in both groups. The Eyhance group demonstrated significantly higher binocular uncorrected and corrected intermediate VA compared with the TECNIS 1-piece group (P<0.001). Defocus and contrast sensitivity values were not significantly different between the two groups. Conclusion Patients who were bilaterally implanted with the new monofocal intraocular lenses achieved significantly higher intermediate VA outcomes without affection of distance VA, with similar mean contrast sensitivity values and low incidence of photic phenomena like halo and glare compared with the standard monofocal lens.

Comparison of Primary Duet Lens Procedures: In-The-Bag Monofocal with Sulcus Multifocal, and Standard Single Multifocal Lens for Cataract Surgery

To assess the safety and efficacy of primary duet intraocular lens (IOL) procedure using an in-The-bag monofocal IOL and a sulcus-based multifocal reversible platform for cataract surgery. The visual outcomes were compared with a single in-The-bag multifocal IOL. Retrospective cohort study. Consecutive patients who underwent primary duet IOL procedures were compared with consecutive patients who underwent single multifocal IOL surgery. Primary outcomes were uncorrected distance and near visual acuities (UDVA and UNVA), refraction and spherical equivalent data. Secondary outcomes included surgical complications. The study group consisted of 32 eyes (22 toric IOLs) whilst the control group had 57 eyes (29 toric IOLs). There were no statistically significant differences between the two groups on post-operative 1-month and 1-year UDVA (p=0.1522 and 0.4926, respectively) and UNVA (p=0.1248 and 0.2738, respectively). There were no statistically significant differences in the postoperative 1-month spherical equivalent within ± 0.5 diopter (p=0.1891). Postoperative intraocular pressure spikes were observed on day-1 in both groups, with most returned to their baseline at 1-month and all were normal at 1-year post surgery. There were no statistically significant differences in intraocular pressure between the two groups on day-1, 1-month and 1-year after surgery (p=0.6421). There were no statistically significant differences in the IOL axis deviation from the intended axis in the toric subgroup analysis (p=0.5843). Primary duet IOL procedure is equally effective and safe in correcting distance and near vision when compared with single multifocal IOL in the capsular bag.

Are Blue-Cut Lenses Safe for Children? Potential Effects on Eye Length and Refractive Disorders

Blue-blocking lenses, including both spectacles and intraocular lenses, are designed to selectively reduce the intensity of short-wavelength visible light and UV radiation using a chromophore. Unlike standard spectacle lenses, which only offer varying degrees of UV protection, blue-blocking lenses provide additional benefits such as enhancing visual performance, reducing eye fatigue from digital screens, protecting the retina from phototoxicity, and minimizing disruption of the circadian rhythm caused by blue light-emitting devices used in the evening. Research has shown that the length of the eye tends to increase over time, especially during the first 10 months of life, indicating the importance of this period in eye development. The Purkinje shift is a phenomenon where the eye becomes more sensitive to blue light in the dark, and it is a normal physiological process. However, there is concern that prolonged use of blue-cut lenses in children may affect the development of eye length and contribute to an increase in refractive eye disorders.

Optical System Design for Micro Medical Electronic Endoscope

The optical fibre endoscope with cold light is still mainstream in the endoscope market, but the inherent structural characteristics of the optical fibre endoscope lead to its shortcomings, such as high price, inconvenient to carry, and easy distortion of image. The micro medical electronic endoscope can receive the front-end optical system image through the miniature CCD (Charge Coupled Device) and transmit the image to the display through the cable, which greatly solves the limitations of the optical fibre endoscope. In this paper, using ZEMAX software, an optical imaging system with 75&#x2218; field of view is designed. The system consists of four lenses, and all of them are standard spherical lenses. The maximum aperture is 2.2&#xA0;mm and can match the 1/10-inch CCD. The distortion of the edge field of view is less than 20%, the aberration is small, and the light convergence is good. The maximum spatial resolution is 175 lp/mm.

Evaluation of the effectiveness of the Super Enhanced Single Vision Lens 01 (SESL01) in reducing symptoms of computer vision syndrome (CVS): A study protocol for a double-blind, two-arm parallel randomized controlled trial

BackgroundThe increased use of digital devices has implications for health and, particularly, the eyes, due to Computer Vision Syndrome (CVS). Millions of individuals of all ages are at risk of CVS, and its prevalence ranges from 25% to 93%. This trial will evaluate the effectiveness of the Super Enhanced Single Vision Lens 01 (SESL01) versus standard single vision lens in reducing symptoms of CVS assessed by the Computer Vision Syndrome Questionnaire (CVS-Q®) scores. MethodA double-blind, two-arm parallel randomized controlled trial will be conducted at the University of Central Lancashire, Preston (UK), recruiting students and staff with CVS-Q score ≥ 6. A 1:1 randomization and a sample size of 300 participants will be sufficient to detect a 2-point difference in the CVS-Q score between the intervention and control groups with an alpha of 5%, two-sided, allowing for a dropout of 10%. The control group will use standard single vision lenses, and the intervention group SESL01. The primary outcome to week 14 will be the difference in the CVS-Q score between SESL01 and standard single vision lenses. Secondary outcomes include the percentage of participants with CVS-Q score < 6 (no symptoms) and CVS-Q score ≥ 6 (symptoms) in the SESL01 and the standard single vision group at weeks 6, 10 and 14; the percentage of participants in each group with a total CVS-Q score < 6, 6–12, 13–19, and ≥ 20 at weeks 6, 10 and 14. The primary analysis will be the intention to treat. DiscussionFindings may inform decisions about adopting the SESL01 lenses to reduce CVS.Trial registration:clinicaltrial.gov identifier: NCT05545878. Registered: Sept. 19, 2022.

Head-mounted optical imaging and optogenetic stimulation system for use in behaving primates

Advances in optical technology have revolutionized studies of brain function in freely behaving mice. Here, we describe an optical imaging and stimulation device for use in primates that easily attaches to an intracranial chamber. It consists of affordable commercially available or 3D-printed components: a monochromatic camera, a small standard lens, a wireless μLED stimulator powered by an induction coil, and an LED array for illumination. We show that the intrinsic imaging performance of this device is comparable to a standard benchtop system in revealing the functional organization of the visual cortex for awake macaques in a primate chair or under anesthesia. Imaging revealed neural modulatory effects of wireless focal optogenetic stimulation aimed at identified functional domains. With a 1 to 2 cm field of view, 100× larger than previously used in primates without head restraint, our device permits widefield optical imaging and optogenetic stimulation for ethological studies in primates.

Optimal approaches to formaldehyde planar laser-induced fluorescence

We assessed approaches to i) detecting formaldehyde (CH2O) via planar laser-induced fluorescence (PLIF) in atmospheric-pressure premixed flames, including those with pre-vaporized jet fuels, and ii) improving signal-to-noise ratio (SNR) of CH2O PLIF more generally. We compared excitation wavelengths and schemes – employing the third-harmonic output of a Nd:YAG laser vs. the frequency-doubled output of a dye laser. Specifically, we identified the optimal excitation line accessible via the frequency-doubled dye laser at 353.07 nm, which was ∼4× more efficient than tripled-Nd:YAG excitation, but considering that the tripled-Nd:YAG laser output is generally ∼10× more energetic, it will produce more CH2O-LIF signal. We then determined the optimal detection setup to include a 100-mm focal length (f/1.4) objective lens coupled to a standard achromatic lens, which provided ∼4× greater signal relative to our baseline lens configuration, and subsequently we demonstrated that a Gen III GaAsP intensifier produced remarkably high PLIF SNR (>15). Measurements in premixed turbulent flames using pre-vaporized kerosene fuels showed that interference from fuel-based LIF was largely absent in all cases and that high-quality CH2O PLIF was efficacious.

Methods to estimate subpixel level small motion from video of vibrating cutting tools

Cutting tools can vibrate with frequencies of up to a few kHz with amplitudes ranging from a few µm to hundreds of µm. To characterize these vibrations using vision-based modal analysis methods, video of vibrating tools must be acquired at high speed and resolution. High speed acquisition will ensure modes are temporally resolved without aliasing, whereas high resolution acquisition ensures that the pixel size is small enough to resolve small motion. However, since most digital cameras trade speed for resolution, estimating small motion of high frequency modes becomes difficult. To address this issue, this paper presents new methods to estimate small motion from video of vibrating cutting tools. Two methods are illustrated on a video of a slender end mill. One is hardware-based, and the other is software-based. In the hardware-based method, we use combinations of extension tubes and a reverse ring fitted with a standard lens to achieve a pixel size of as less as 1.3 µm. In the software-based method, we leverage the capability of intensity- and phase-based motion registration methods to detect small subpixel level motion, even when the pixel size is 83 µm. In both methods we use the object’s own features to detect and register motion, thus overcoming the limitation of digital image correlation schemes that need markers for target tracking. Modal parameters evaluated from motion estimated with both methods are found to agree with those extracted from twice integrated accelerations. Since methods proposed herein proffer new ways to register small oscillatory motion, we believe that our findings will further help leverage the adoption of vision-based modal analysis methods in machine tool systems as an alternative to the more traditional experimental modal analysis procedures.

Tunable two-element diffractive lenses with optimal bandwidth utilization.

Previous work has shown that a set of two diffractive optical elements arranged in series can form a diffractive lens with variable optical power that can be tuned by relative rotation of its two sub-elements about their common central axis. However, previous designs of these diffractive optical elements did not take advantage of the full spatial resolution required for the fabrication process because the corresponding sub-elements consisted of both, regions with very high phase gradients (requiring full resolution) and other extended regions with nearly vanishing phase gradients, where the available resolution is "wasted". Here, an advanced design is proposed that exploits the full spatial bandwidth of the production system. This is done by increasing the polar (angular) phase gradient of each sub-element such that it approaches the usually much larger radial phase gradient. A pair of these new sub-elements then composes a diffractive lens that has the same tuning range of its optical power than a standard tunable diffractive lens, but advantageously achieved within a much smaller relative rotation range. This has advantages in systems where high speed tuning of optical power is required, and in systems where the rotation angle is limited.

Investigations on the potential application of machine vision lenses for depth measurement by exploiting chromatic aberrations

Chromatic (spectral) aberrations are image imperfections that are disadvantageous for standard image processing tasks and are typically compensated through the application of different types of glass during lens design. The longitudinal chromatic aberration causes a relative unsharpness over different spectral channels. Since this error is corrected in most multi-chromatic lenses, this paper investigates to which extent the shift of the focal planes in a standard lens can be used specifically for image processing applications. Theoretical investigations of the longitudinal chromatic aberration are carried out. Based on this, conditions and a method to generate a 3D depth reconstruction out of different spectral channels are presented.

Electrically tunable lens with a non-monotonic wavefront control capability.

We describe an electrically tunable liquid crystal lens that can produce a rich variety of wavefronts, including sombrero-type (non-monotonic) phase modulation, enabling the focusing of light into a ring-shaped intensity distribution. The lens can also generate axicons or standard spherical lenses with a bipolar response (providing both positive and negative optical powers). The design of the lens requires only a single-step lithography process, dramatically simplifying its manufacturing. We describe various driving modes of this lens and present the first experimental results and discuss its possible applications in miniature cameras and microscopes. We think that this device can revolutionize the optical design in many areas of photonics.

A Cost-Effectiveness Analysis of AcrySof IQ Vivity Intraocular Lens (IOL) from Private Health Fund Perspective in Australia

PurposeAcrySof IQ Vivity is a unique non-diffractive extended depth of focus intraocular lens with wavefront-shaping X-WAVE technology. This study evaluated the cost-effectiveness of AcrySof IQ Vivity intraocular lens (DFT015) compared with standard aspheric monofocal intraocular lens (SN60WF), from a private health fund perspective in Australia.MethodsA Markov model was developed using the following health states: well, need for spectacles (near/distance/bifocal/varifocal), very bothersome visual disturbances (glare/haloes/starbursts) – with/without spectacles, and death. Model inputs were sourced from a randomized clinical study (NCT03010254), published literature, prostheses list and clinical opinion. A lifetime horizon (up to 30 years) was considered, and cost and health outcomes were discounted at 5% per annum. Model outcomes included incremental cost–effectiveness ratio defined as incremental cost per quality adjusted life year gain. Sensitivity and scenario analyses were also conducted.ResultsBilateral implantation of DFT015 intraocular lens provided quality adjusted life year gain of 0.16 at an incremental cost of AU$307 compared to bilateral SN60WF, leading to an incremental cost-effectiveness ratio of AU$1908/quality adjusted life year, well below the cost-effectiveness threshold (Range: AU$45,000-AU$75,000) typically used by Medical Services Advisory Committee in Australia. Results were most sensitive to intraocular lens costs, post-operative spectacle dependence, and disutility due to wearing glasses. Robustness of the results was further confirmed by probabilistic sensitivity analysis and scenario analyses.ConclusionAcrySof IQ Vivity intraocular lens is a highly cost-effective treatment strategy with improved vision-related quality of life outcomes for presbyopic cataract surgery patients.

Comparative analysis of a presbyopia-correcting intraocular lens that combines extended depth-of-focus and bifocal profiles with a standard monofocal intraocular lens

BackgroundRecently, a new presbyopia-correcting intraocular lens (IOL) that combines extended depth-of-focus and bifocal profiles (ZFR00: Tecnis® Synergy®, Johnson & Johnson Vision, Santa Ana, CA, USA) has been established and several studies have been reported. We attempted to compare the performance with a standard IOL (ZCB00: Tecnis® monofocal, Johnson & Johnson Vision, Santa Ana, CA, USA) manufactured using the same material from the same company, which has been extensively used worldwide.MethodsThe medical records of patients undergoing cataract surgery with ZCB00 or ZFR00 implantation between March 2021 and September 2021 and with available 3-month visit data were reviewed. Uncorrected near, intermediate, and distance visual acuity (VA), corrected distance VA, and optical quality were the main outcome measures.ResultsThis study included forty-six patients (64 eyes), with twenty-one patients (32 eyes) implanted with ZCB00 and twenty-five patients (32 eyes) implanted with ZFR00. The average age of the patients was 66.0 ± 10.1 (range: 40 to 82) and 65.1 ± 4.7 (range: 59 to 77) years in the ZCB00 and ZFR00 groups, respectively. The preoperative characteristics did not differ significantly between the two groups. Compared to the ZCB00 group, the ZFR00 group demonstrated significantly superior intermediate and near VA (p < 0.001) at 3 months postoperatively. The ZFR00 group showed significantly lower objective measured optical quality than that in the ZCB00 group.ConclusionsThe ZFR00 exhibited a continuous range of vision and a smooth defocus curve, while the ZCB00 provided superior objective optical quality.

Enhancing the optical response and biosensing capabilities of bioinspired peptide micro-waveguides exploiting chromatic aberration.

Bioinspired peptide waveguides of mesoscopic length scales have established a new paradigm in photonics with possible applications in precision bioimaging, sensing, and diagnostics. Here, we improve the efficiency of coupling various constituent colors of a white light source into single self-assembled microtube-shaped passive peptide waveguides by employing chromatic aberration. Thus, we use a chromatically aberrated microscope objective lens to couple light into peptide waveguides. Using both numerical simulation and experiments, we show that the waveguide response displays higher quality factor, wavelength selectivity, and axial coupling range compared to a chromatically corrected standard plan-fluoritic objective lens. We also demonstrate absorption and refractive index-based sensing by studying the changes in the optical responses of the peptide tubes in the presence of a wide concentration range of the absorptive Congo red, and the nonabsorptive Coumarin dyes. The former understandably display a much higher response than the latter due to the low finesse of the waveguides. We obtain a detection limit of around 10nM for Congo red, and 10 mM for Coumarin. Our study opens up possibilities for deploying such peptide microtubes for various biosensing applications utilizing spectral and waveguide characteristics.

Clinical and Aberrometric Evaluation of a New Monofocal IOL with Intermediate Vision Improvement.

Purpose The aim of the study was to evaluate the visual outcomes, aberrometric results, and subjective and objective optical qualities 12 months after implantation of a new monofocal intraocular lens (Physiol IsoPure 1.2.3) in comparison with a standard monofocal intraocular lens (Tecnis PCB00). Materials and Methods Cataract patients without ocular comorbidities had bilateral implantation of the IsoPure IOL or the PCB00 IOL. One month after eye surgery, the visual acuity and monocular defocus curve were assessed. Twelve months after surgery, the visual acuity, binocular defocus curve, contrast sensitivity, and subjective/objective optical quality were assessed. Furthermore, wavefront analysis was performed. The primary endpoint was the best distance correct/uncorrected visual acuity at intermediate and far distances. The secondary endpoint was an aberration evaluation of the IOLs and contrast sensitivity. Results The study comprised a total of 42 patients (84 eyes). Monocular and binocular uncorrected and corrected distance were similar between groups, and uncorrected intermediate visual acuity was significantly higher in the IsoPure group. There was no difference in contrast sensitivity and subjective and objective optical qualities. The optical aberrations at 3.0 and 5.0 mm aperture diameters were similar in both groups. Conclusion The IsoPure IOL, based on greater depth of focus than the aspheric monofocal IOL, may offer a good option for the distance and intermediate vision without increasing optical aberrations and any photic phenomena.

An Improved GPU-based Ray-shooting Code for Gravitational Microlensing

We present an improved inverse-ray-shooting code based on graphics processing units (GPUs) to generate microlensing magnification maps. In addition to introducing GPUs to accelerate the calculations, we also invest effort into two aspects: (i) A standard circular lens plane is replaced by a rectangular one to reduce the number of unnecessary lenses as a result of an extremely prolate rectangular image plane. (ii) An interpolation method is applied in our implementation, achieving significant acceleration when dealing with the large number of lenses and light rays required by high-resolution maps. With these applications, we have greatly reduced the running time while maintaining high accuracy: The speed was increased by about 100 times compared with an ordinary GPU-based inverse-ray-shooting code and a GPU-D code when handling a large number of lenses. If a high-resolution situation with up to 10,0002 pixels, resulting in almost 1011 light rays, is encountered, the running time can also be reduced by two orders of magnitude.

Depth of focus extension in optical coherence tomography using ultrahigh chromatic dispersion of zinc selenide.

We report a novel technique to overcome the depth-of-focus limitation in optical coherence tomography (OCT) using chromatic dispersion of zinc selenide lens. OCT is an established method of optical imaging, which found numerous biomedical applications. However, the depth scanning range of high-resolution OCT is limited by its depth of focus. Chromatic dispersion of zinc selenide lens allows to get high lateral resolution along extended depth of focus, because the different spectral components are focused at a different position along axes of light propagation. Test measurements with nanoparticle phantom show 2.8 times extension of the depth of focus compare to the system with a standard achromatic lens. The feasibility of biomedical applications was demonstrated by ex vivo imaging of the pig cornea and chicken fat tissue.

Visual and optical quality of enhanced intermediate monofocal versus standard monofocal intraocular lens

PurposeIntraocular lens designs are constantly evolving, trying to obtain more spectacle independence after cataract surgery. This advantage can be linked to some disadvantages, such as optical quality decrease. For that reason, it is important to assess, not only the amount of vision provided but also the quality of vision once they are implanted. The purpose of the present work was to compare the visual performance between two monofocal intraocular models: a standard model and a monofocal with enhanced intermediate vision lens.MethodsProspective, randomized, comparative study. Sixty adult subjects scheduled to undergo bilateral cataract surgery and IOL implantation were randomized to receive one of the two IOLs in both eyes at Miranza IOA, Madrid, Spain (group A: monofocal with enhanced intermediate vision lens and group B: standard monofocal lens). Monocular outcomes (right eyes) determined 1 and 3 months postoperatively were photopic corrected distance visual acuity (CDVA), uncorrected distance visual acuity (UDVA), perceived halo, corrected intermediate-distance contrast sensitivity, and higher-order aberrations. The impact of the new IOL in the postoperative management with autorefraction devices was also evaluated.ResultsNo differences were found in CDVA between the two groups. Significant differences were detected between the two lenses evaluated in both total HOA (p = 0.028) and internal HOA (p = 0.037). Contrast sensitivity and halometry results obtained at 1 month were similar across the two IOL groups.ConclusionIn patients undergoing cataract surgery, monofocal with enhanced intermediate vision IOL offered similar distance performance and contrast sensitivity along with perceived HOA and halos compared with the standard monofocal IOLs tested.

Exploring Vision-Related Quality of Life: A Qualitative Study Comparing Patients' Experience of Cataract Surgery with a Standard Monofocal IOL and an Enhanced Monofocal IOL.

PurposeTo explore quality of life related with intermediate vision of patients before and after cataract surgery, and to make patients’ experience available for the design of future scales that assess visual function related with intermediate distance.Patients and MethodsA qualitative research methodology based on thematic content analysis was used to explore vision-related quality of life based on the experiences of patients with cataract. Patients were recruited at the Service of Ophthalmology of the Hospital de Sant Pau (Barcelona, Spain). Data were collected through nineteen semi-structured interviews conducted with patients diagnosed with cataract and implanted with a standard aspheric monofocal intraocular lens (IOL) (Tecnis® ZA9003) (n = 6), an enhanced monofocal IOL (Tecnis® Eyhance ICB000) (n = 6), and patients from the waiting list (n = 7). The data analysis consisted in coding, aggregation, and theme development of the transcribed audios.ResultsPatients on waiting lists reported difficulty and insecurity in performing daily and meaningful tasks related to near visual ranges (eg: threading a needle, reading price tags), intermediate (eg: using a computer or dialling numbers on a smartphone), and distant (eg: recognizing faces, walking on uneven surfaces). Patients after surgery with the standard IOL reported improvement in performing activities mainly in the distant visual range, but also the need for a better communication with clinical staff to adjust their own expectations on the results of the surgery. Finally, patients implanted with the enhanced IOL reported satisfaction and improved visual function in performing daily activities, especially those related to the intermediate visual range.ConclusionOur exploratory study found that patients after cataract surgery with the enhanced IOL reported a better performance in activities that require the intermediate vision. These results will inform the development of scales to assess vision-related quality of life in the intermediate visual range prioritizing outcomes according to patients’ daily and meaningful activities.

Measuring aniseikonia and investigating neuroplasticity and image factors in amblyopia (MAGNIFY): study protocol for a randomised clinical trial

BackgroundAniseikonia represents a potential barrier to neuroplasticity which may limit visual outcomes in children with anisometropic amblyopia. Full correction of refractive error is the first step in standard amblyopia treatment, which corrects for image focus but neglects image size differences.MethodsThe MAGNIFY study is a double-masked, randomised clinical trial investigating the effectiveness of aniseikonia correcting lenses in children at first diagnosis of significant anisometropia. We hypothesis that aniseikonia correction lenses will improve image clarity and reduce the retinal size differences producing better visual acuity and stereoacuity improvements after 15 weeks of optical treatment for children with anisometropia. Eligible children will be randomly allocated to the treatment group (aniseikonia-correcting spectacle lenses) or control group (standard spectacle lenses). Visual acuity and binocular functions will be assessed every 5 weeks during the 15-week optical treatment phase according to standard amblyopia treatment protocol.DiscussionIt is possible that correcting aniseikonia along with anisometropia at first diagnosis will promote binocularity as well as increase spectacle adherence by reducing visual discomfort, improving optical treatment outcomes. This could then reduce the need for additional amblyopia treatment such as patching or atropine, reducing the burden on hospital eye departments and potentially improving visual outcomes for children with amblyopia.Trial registrationAustralian New Zealand Clinical Trials Registry (ANZCTR) ACTRN12620000061932. Registered on 24 January 2020. Protocol 15th November 2019, version one.