Refractive Devices Research Articles

Abstract PO2-12-11: Ocular Toxicity of Tamoxifen in Patients with Breast Cancer

Abstract Background: The latest recommendations in breast cancer treatment protocols with tamoxifen indicate that it should be used from five to 10 years. It depends mainly on the cumulative dose of the drug in the body. Despite its multiplicity, the various studies conducted on this subject did not reach conclusive results. Objectives: This research aims to study retinopathy associated with hormonal treatment of breast cancer using tamoxifen. Methods: A cross-sectional study was conducted at Al-Mouwasat University Hospital on a sample of 130 eyes according to (G-Power) with a statistical power of 95%. The participants were briefed on the research and consented on the ethical considerations. Then, the patients who entered the study were interrogated, clinically examined, and were asked about their medical history, the time of breast cancer diagnosis along with the details about the treatment protocols they underwent or currently undergoing. The refractive errors were measured with an automatic refractive device, then they were examined on the slit lamp to investigate the refractory media, then the corrected and uncorrected visual acuity were taken. Finally, after ensuring that the inclusion criteria were met and excluding those who fulfil one or more of the exclusion criteria, optical coherence tomography was performed using SD-OCT technique to measure and review the retinal thickness map in circles of 1-3-6 mm, respectively, to notice possible changes on it. Results: We found that the use of tamoxifen irrespective to cumulative dose leads to increase in the macula thickness values in the upper and lower sectors within the 3 mm circle, and to significant decrease in the macula thickness values in the upper and lower sectors within the 6 mm circle, in addition to decrease in nasal sector thickness within the circles of 3 and 6 mm. Conclusion: We conclude that the difference between people treated with tamoxifen and those not treated with it is not limited to the occurrence of crystals deposition in the macular area or the presence of a cavity in the central macula (with or without typical cystic macular edema), but rather to existence of macula thickness differences unrelated to the cumulative dose of the drug, whether by increase or decrease in thickness of the upper, lower and nasal segments. Citation Format: Husain Alhouz, Arwa Azmeh, Maher Saifo. Ocular Toxicity of Tamoxifen in Patients with Breast Cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-12-11.

Enhanced negative refraction in one- and two-dimensional chiral atomic lattices

We consider a physical scheme for the realization of optical lattices that have negative refracting under certain conditions. The lattice is formed by clusters of five-level closed-loop chiral atoms assumed to have a Gaussian density distribution in dipole traps along one or two dimensions. With a suitable combination of strong standing wave control fields, spatial symmetry of atoms is achieved. Besides, the dispersion properties of an atomic lattice can be modified conveniently by adjusting various parameters related to the atoms or the lattice. We show that negative-like refraction is not specific to the atoms themselves, but also emerges due to the periodicity of the lattice. We further reveal that the refraction is negative over specific regions on the lattice and strongly depends on the number of atoms trapped along a particular direction. Our model is effectively controllable remotely and may have applications in negative refraction devices and optical information processing.

Ametropia detection using a novel, compact wavefront autorefractor.

Despite the well-known reproducibility issues of subjective refraction, most studies evaluating autorefractors compared differences between the device and subjective refraction. This work evaluated the performance of a novel handheld Hartmann-Shack-based autorefractor using an alternative protocol, which considered the inherent variability of subjective refraction. Participants underwent an initial measurement with a desktop autorefractor, two subjective refractions (SR1 and SR2) and a final measurement with the QuickSee Free (QSFree) portable autorefractor. Autorefractor performance was evaluated by comparing the differences between the QSFree and each of the subjective refractions with the difference between the subjective refractions (SR1 vs. SR2) using Bland-Altman analysis and percentage of agreement. A total of 75 subjects (53 ± 14 years) were enrolled in the study. The average difference in the absolute spherical equivalent (M) between the QSFree and the SR1 and SR2 was ±0.24 and ±0.02 D, respectively, that is, very similar or smaller than the SR1 versus SR2 difference (±0.26 D). Average differences in astigmatic components were found to be negligible. The results demonstrate that differences between QSFree and both subjective refractions in J0 and J45 were within ±0.50 D for at least 96% of the measurements. The limits of agreement (LOAs) of the differences between QSFree and SR1, as well as QSFree and SR2, were higher than those observed between SR1 and SR2 for M, J0 and J45 . A protocol was designed and validated for the evaluation of a refractive device to account for the variability of subjective refraction. This protocol was used to evaluate a novel portable autorefractor and observed a smaller difference between the device and subjective refractions than the difference between the two subjective refraction measurements in terms of mean bias error, although the standard deviation was higher.

Ultratransparent photonic crystals realize positive and negative refractions

The introduction of ultratransparent medium has not yet solved the problem of transmission loss caused by reflection in negative refraction (NR) devices. In this study, theoretical analysis and simulation verification are carried out and an ultratransparent medium with wide-angle NR-index is proposed; the imaging with its flat lens is discussed. A photonic crystal (PC) is designed as an instance of the medium, and the rationality was analyzed. The PC can realize NR within 50° as well as positive refraction (PR) within 75° with transmittances over 99%. It is an ideal material for multifunctional NR/PR devices with ultra-low loss.

Dielectric Metalens by Multilayer Nanoimprint Lithography and Solution Phase Epitaxy

Metasurfaces have ushered in a huge development for their superior ability in manipulating light properties including phase, amplitude, and polarization, which show great potential as alternatives for the refractive optical devices. Recently, many applications of metasurface including metalens have been proposed and investigated, aiming at substituting their refractive counterparts. However, the commonly used fabrication approaches employ electron‐beam lithography (EBL) followed by dry etching or atomic layer deposition (ALD) of dielectric materials, which are expensive and inefficient. Besides, dry etching of dielectric materials at sub‐100 nm scale with a high aspect ratio is challenging. Herein, a new approach for dielectric metalens fabrication is presented, which combines multilayer nanoimprint lithography and solution phase epitaxy. High aspect ratio ZnO nanopillars with a height‐to‐diameter ratio of over 7:1 are demonstrated. By using the multilayer nanoimprint lithography, increased aspect ratio nanostructures from shallow imprinting molds are obtained. The highly anisotropic growth characteristic enables nanopillars to grow at a height that exceeds the resist thickness. With this ability, ZnO metalenses are fabricated where the height of nanopillar reaches 1.1 μm, achieving a focusing efficiency of 50%. The process is cost‐effective with a high throughput, which can be widely used for many optical applications.

Impact of Self‐Absorption and Cavity Effects on the Electroluminescence Spectra of Thin‐Film Solar Cells

Thin‐film organic and perovskite solar cells have seen tremendous advances in recent years. A common technique to characterize the low‐energy states in these solar cells is electroluminescence spectroscopy. Stemming from their thin film nature, however, the outcoupled electroluminescence spectra of these devices are affected by cavity effects and self‐absorption. Herein, a modeling approach is developed taking into account self‐absorption, cavity effects, and a nonhomogeneous emission profile, to correct the outcoupled spectrum, thereby yielding the intrinsically emitted spectrum. The modeling approach is then employed to structurally investigate the impact of these effects for a variety of active layer thicknesses, complex refractive indices, device structures, and emission profiles. The data presented uncover trends and provide guidelines that enable gauging the impact of self‐absorption and cavity effects on the electroluminescence spectra of a large set of thin‐film devices.

Multifunctional Plasmon-Induced Transparency Devices Based on Hybrid Metamaterial-Waveguide Systems.

In this paper, we design a multifunctional micro-nano device with a hybrid metamaterial-waveguide system, which leads to a triple plasmon-induced transparency (PIT). The formation mechanisms of the three transparent peaks have their own unique characteristics. First, PIT-I can be switched into the BIC (Friedrich–Wintge bound state in continuum), and the quality factors (Q-factors) of the transparency window of PIT-I are increased during the process. Second, PIT-II comes from near-field coupling between two bright modes. Third, PIT-III is generated by the near-field coupling between a low-Q broadband bright mode and a high-Q narrowband guide mode, which also has a high-Q transparent window due to the guide mode. The triple-PIT described above can be dynamically tuned by the gate voltage of the graphene, particularly for the dynamic tuning of the Q values of PIT-I and PIT-III. Based on the high Q value of the transparent window, our proposed structure can be used for highly sensitive refractive index sensors or devices with prominent slow light effects.

Absorption and Self-Calibrated Sensing Based on Tunable Fano Resonance in a Grating Coupled Graphene/Waveguide Hybrid Structure

A grating coupled graphene surface plasmon and planar waveguide structure is investigated. A sharp asymmetric profile Fano resonance attributed by the coupling between the graphene plasmon and the waveguide mode can be observed. The physical origin of Fano resonance are analyzed by electric field distribution, and the tunable Fano resonances with different line profiles are demonstrated by varying the Fermi level and the incident angle. The further studies demonstrate the Fano resonance has a potential application in light absorption and the absorption can reach 76% when graphene carrier mobility is 0.5 m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> /(Vs). In addition, the Fano resonance could potentially be applied as a self-referenced refractive index sensor due to the decoupled property of Fano resonance and a sensitivity of 5.21 μm/RIU can be achieved. Thus, the Fano resonance we proposed in the work would have great prospects in developing excellent light absorption and refractive index sensor functional devices.

A new trifocal corneal inlay for presbyopia

Corneal inlays (CIs) are the most recent surgical procedure for the treatment of presbyopia in patients who want complete independence from the use of glasses or contact lenses. Although refractive surgery in presbyopic patients is mostly performed in combination with cataract surgery, when the implantation of an intraocular lens is not necessary, the option of CIs has the advantage of being minimally invasive. Current designs of CIs are, either: small aperture devices, or refractive devices, however, both methods do not have good performance simultaneously at intermediate and near distances in eyes that are unable to accommodate. In the present study, we propose the first design of a trifocal CI, allowing good vision, at the same time, at far, intermediate and near vision in presbyopic eyes. We first demonstrate the good performance of the new inlay in comparison with a commercially available CI by using optical design software. We next confirm experimentally the image forming capabilities of our proposal employing an adaptive optics based optical simulator. This new design also has a number of parameters that can be varied to make personalized trifocal CI, opening up a new avenue for the treatment of presbyopia.

A Polarimetric Interferometer Based on Composite Optical Waveguide for Refractive Index Detection

A sensitive interference refractive index sensor based on composite optical waveguide (COWG) was developed. Sol-gel technique was used to prepare TiO2 sol, and the TiO2 film was fixed on the surface of single-mode potassium ion-exchange (PIE) optical waveguide (OWG) by dip-coating and annealing treatment to fabricate an interference refractive index sensor device. The interference between the zeroth-order transverse electric (TE0) and magnetic (TM0) modes of the laser beam which transport in the COWG caused phase-difference change (Δϕ) of output light signals. Refractive index sensitivity of TiO2/PIE COWG chip was examined by injecting aqueous NaCl solutions and distilled water in turn to detect its Δϕ. Experimental results show that, for the TiO2/PIE COWG its refractive index sensitivity is SRI = (573.09 × 2π)/RIU in the refractive index ranges of 1.3386∼1.36. The sensor sees the advantages of high sensitivity, compact size, simple fabrication, as well as low cost.

Двохелементні мікропризмові лінзи

Розглянуто оптичні параметри кругових мікропризмових заломлюючих пристроїв, які створені з двох ідентичних концентраторів світлових потоків із заданими граничними кутами заломлення променів. Виконано моделювання індикатриси променів для двохелементних рефракційних елементів. Розраховано параметри зменшення світлопропускання лінійних двохелементних пристроїв, які використовуються в офтальмології для визначення кута рефракції променів.

Validation of a portable, remotely delivered refraction approach compared to standard in-clinic refraction in a low-vision population

Introduction A low-vision assessment (LVA) is critical in developing a vision rehabilitation plan. A remotely delivered LVA that replicates a standard in-clinic assessment may bridge the gap for patients not accessing care due to the limited quantity and distribution of low-vision providers. Within an LVA, an accurate and consistent assessment of refraction error is an essential component. No system has currently been validated for the purposes of a remote LVA. The purpose of this study was to validate a commercially available portable refraction approach in a low-vision population. Methods Low-vision patients (n = 26) or normally sighted patients (n = 25) underwent a refraction assessment using the Adaptica® 2WIN autorefractor, adaptor scope (Kaleidos) and VisionFit phoropter portable refraction devices, as well as a standard autorefractor (Huvitz) and phoropter (Haag-Streit). Refraction data between systems and populations were compared using intraclass correlations. Bland–Altman plots were used to assess the differences between devices. Results Spherical equivalent values were found to be reproducible between standard and experimental autorefraction devices (intraclass correlation coefficient (ICC) > 0.8) in both low-vision and normally sighted groups. Similarly, manifest refraction was highly consistent (ICC > 0.8) between devices in all groups. The Bland–Altman plots showed clinically acceptable mean differences of 0.701 between autorefraction methods and –0.116 between manifest refraction methods. Discussion The 2WIN/VisionFit system can reliably generate refraction values across a spectrum of errors in normally sighted and visually impaired people, and would be feasible to deliver remotely.

Artificial intelligence in cornea, refractive, and cataract surgery

The subject of artificial intelligence has recently been responsible for the advancement of many industries including aspects of medicine and many of its subspecialties. Within ophthalmology, artificial intelligence technology has found ways of improving the diagnostic and therapeutic processes in cornea, glaucoma, retina, and cataract surgery. As demands on the modern ophthalmologist grow, artificial intelligence can be utilized to help address increased demands of modern medicine and ophthalmology by adding to the physician's clinical and surgical acumen. The purpose of this review is to highlight the integration of artificial intelligence into ophthalmology in recent years in the areas of cornea, refractive, and cataract surgery. Within the realms of cornea, refractive, and cataract surgery, artificial intelligence has played a major role in identifying ways of improving diagnostic detection. In keratoconus, artificial intelligence algorithms may help with the early detection of keratoconus and other ectatic disorders. In cataract surgery, artificial intelligence may help improve the performance of intraocular lens (IOL) calculation formulas. Further, with its potential integration into automated refraction devices, artificial intelligence can help provide an improved framework for IOL formula optimization that is more accurate and customized to a specific cataract surgeon. The future of artificial intelligence in ophthalmology is a promising prospect. With continued advancement of mathematical and computational algorithms, corneal disease processes can be diagnosed sooner and IOL calculations can be made more accurate.

High Refractive Index Electromagnetic Devices in Printed Technology Based on Glide-Symmetric Periodic Structures

We demonstrate the beneficial effects of introducing glide symmetry in a two-dimensional periodic structure. Specifically, we investigate dielectric parallel plate waveguides periodically loaded with Jerusalem cross slots in three configurations: conventional, mirror- and glide-symmetric. Out of these three configurations, it is demonstrated that the glide-symmetric structure is the least dispersive and has the most isotropic response. Furthermore, the glide-symmetric structure provides the highest effective refractive index, which enables the realization of a broader range of electromagnetic devices. To illustrate the potential of this glide-symmetric unit cell, a Maxwell fish-eye lens is designed to operate at 5 GHz. The lens is manufactured in printed circuit board technology. Simulations and measurements are in good agreement and a measured peak transmission coefficient of −0.5 dB is achieved.

Miadında Doğan Türk Bebeklerde Refraktif Kusurların Taşınabilir Otorefraktometre ile Taranması

Background : In order to improve the quality of life of newborns, it is important to detect the earliest visual problems. This study aimed to determine the refractive status in healthy term babies and to investigate whether there is a correlation between refractive status and birth weight Materials and Methods: Two hundred and three healthy full-term babies at an age of postnatal 8 weeks were included in the study. In order to evaluate refractive status handheld autorefractometer device was used in all subjects. The types of refractive errors were analyzed both in right and left eyes separately. Measurements taken under cycloplegic condition were analyzed for spherical equivalent, astigmatism and anisometropia. Results : Hypermetropia was found as the most common refractive error among the participants (65% in right eyes, 62% in left eyes). With the rule astigmatism is found to be the most common astigmatic pattern in both eyes (75% in right eyes, 70% in left eyes). Anisometropia incidence was found to be 8%. No correlation between refractive status and birth weight (p=0.105 r=-0.280) Conclusion: Hypermetropia and with the rule astigmatism is the most common refractive error in term babies and there is no relationship between refractive status and birth weight in healthy infants born in term.

折射型红外微透镜阵列器件的发展及制备

折射型红外微透镜阵列器件的发展及制备

Relationship between refractive correction, visual symptoms, and optical device selection for low-vision patients in Taiwan

According to Taiwan optometry act, low-vision services, such as refractive correction and low vision assessment, are now included in Optometric profession. This study was designed to investigate the efficiency of refractive correction and the relationship between refractive correction, eye diseases, visual symptoms, and optical device selection for patients with low vision. MethodsThis study involved a total of 220 participants aged from 7 to 99, with 119 males and 101 females. All of them were referred from three institutes of Taiwan Resource Portal of Assistive Technology under the supervision of the Ministry of Health and Welfare during Feb 2016 to Jan 2018. Accordingly, 42, 76, and 102 of the participants were identified as having mild, moderate, and severe visual impairments, respectively, by five experienced and licensed optometrists for this comprehensive low vision examination. ResultsThe most common eye diseases in this study were retinal disease, cataract, glaucoma, and optic nerve hypoplasia; some of the participants had multiple eye diseases while participating in the study. Except visual acuity decrease, eye diseases were highly correlated with participants’ visual symptoms. Refractive correction is the first step in low-vision examination, therefore, it might be much helpful to some types of eye diseases, visual symptoms, and to the decisions of optical devices for low-vision patients. The results herein suggest that color vision and contrast sensitivity should be taken into consideration when calculating the second optical magnifying power after refractive correction. ConclusionsRefractive correction is necessary for the treatment of patients’ visual symptoms and also for the prescription of low-vision aids.

Smart Lenses with Electrically Tuneable Astigmatism

The holy grail of reconfigurable optics for microscopy, machine vision and other imaging technologies is a compact, in-line, low cost, refractive device that could dynamically tune optical aberrations within a range of about 2–5 wavelengths. This paper presents the first electrically reconfigurable, fully elastomeric, tuneable optical lenses with motor-less electrical controllability of astigmatism in the visible range. By applying different voltage combinations to thin dielectric elastomer actuator segments surrounding a soft silicone lens, we show that the latter can be electrically deformed either radially or along selectable directions, so as to tune defocus or astigmatism, up to about 3 wavelengths. By mounting the new lenses on a commercial camera, we demonstrate their functionality, showing how electrically reconfiguring their shape can be used to dynamically control directional blurring while taking images of different targets, so as to emphasize directional features having orthogonal spatial orientations. Results suggest that the possibility of electrically controlling aberrations inherent to these smart lenses holds promise to develop highly versatile new components for adaptive optics.

Measurement of optical characteristics of catadioptric retroreflectors

A technique for determining the effective scattering area of retroreflective catadioptric (reflective&#x2013;refractive) devices is presented. An experimental setup for measuring the effective scattering area and comparative calculated and measurement data on the effect of fabrication errors on the characteristics of retroreflective elements are presented.

Low-cost high integration IR polymer microlens array.

In this Letter, a low-cost refractive convex microlens array device based on infrared a polymer is fabricated by a nanoimprinting technique. The device integrates more than 4000 microlenslets within a footprint of 10 mm×10 mm. The surface quality, spectral transmittance, imaging resolution, and surface damage threshold of the device have been fully characterized. The IR imaging and parallel laser inscription experiments confirm the remarkable optical performance of the fabricated device. Owing to the merits of high optical quality, low fluence lose, and simple fabrication, this device is promising in cutting-edge IR applications, such as IR imaging, laser fabrication, and so on.