Visual Function Research Articles

Retinal OCT biomarkers associated with reading performance in patients with persistent vs. resolved diabetic macular edema.

Recent advancements in imaging technologies, particularly structural optical coherence tomography (OCT), have improved the understanding of diabetic macular edema (DME) pathophysiology and provided valuable biomarkers for disease progression and visual outcomes. This prospective study aimed to investigate the association between specific retinal biomarkers identified through OCT imaging and reading performance metrics in patients with previously treated persistent versus resolved DME and good visual acuity. Forty-nine eyes from 35 patients with a history of DME were enrolled. Reading performance was assessed using the Radner reading charts, which include standardized sentences with geometrically progressing print sizes. Structural alterations in the inner and outer retina, as well as the retinal pigment epithelium (RPE), were graded based on OCT images. Reading performance, measured as maximum reading speed, was associated with specific retinal biomarkers. The disruption of the ellipsoid zone (EZ) in the parafoveal region and the presence of disorganization of the inner retinal layers (DRIL) in the parafovea were correlated with reduced reading speed. These associations were independent of the presence of intraretinal or subretinal fluid. Understanding the relationship between retinal biomarkers and reading performance could contribute to a comprehensive evaluation of visual function and quality of life in patients with DME, leading to better management strategies and treatment outcomes.

Complement propagates visual system pathology following traumatic brain injury

BackgroundTraumatic brain injury (TBI) is associated with the development of visual system disorders. Visual deficits can present with delay and worsen over time, and may be associated with an ongoing neuroinflammatory response that is known to occur after TBI. Complement system activation is strongly associated with the neuroinflammatory response after TBI, but whether it contributes to vision loss after TBI is unexplored.MethodsAcute and chronic neuroinflammatory changes within the dorsal lateral geniculate nucleus (dLGN) and retina were investigated subsequent to a moderate to severe murine unilateral controlled cortical impact. Neuroinflammatory and histopathological outcomes were interpreted in the context of behavioral and visual function data. To investigate the role of complement, cohorts were treated after TBI with the complement inhibitor, CR2-Crry.ResultsAt 3 days after TBI, complement component C3 was deposited on retinogeniculate synapses in the dLGN both ipsilateral and contralateral to the lesion, which was reduced in CR2-Crry treated animals. This was associated with microglia morphological changes in both the ipsilateral and contralateral dLGN, with a less ramified phenotype in vehicle compared to CR2-Crry treated animals. Microglia in vehicle treated animals also had a greater internalized VGlut2 + synaptic volume after TBI compared to CR2-Crry treated animals. Microglia morphological changes seen acutely persisted for at least 49 days after injury. Complement inhibition also reduced microglial synaptic internalization in the contralateral dLGN and increased the association between VGLUT2 and PSD95 puncta, indicating preservation of intact synapses. Unexpectedly, there were no changes in the thickness of the inner retina, retinal nerve fiber layer or retinal ganglion layer. Neuropathological changes in the dLGN were accompanied by reduced visual acuity at subacute and chronic time points after TBI, with improvement seen in CR2-Crry treated animals.ConclusionTBI induces complement activation within the dLGN and promotes microglial activation and synaptic internalization. Complement inhibition after TBI in a clinically relevant paradigm reduces complement activation, maintains a more surveillance-like microglia phenotype, and preserves synaptic density within the dLGN. Together, the data indicate that complement plays a key role in the development of visual deficits after TBI via complement-dependent microglial phagocytosis of synapses within the dLGN.

Piloting Rasch model scoring of the National Eye Institute Visual Function Questionnaire in uveitis

IntroductionThe National Eye Institute Visual Function Questionnaire (NEI VFQ) is a common patient-reported outcome measure (PROM) in uveitis trials. Its psychometric properties using state-of-the-art scoring based on Rasch models, a latent trait model that improves accuracy of PROMs assessment, has not yet been investigated.MethodsThe study participants were recruited online from uveitis patient organizations, where individuals self-reported their uveitis diagnosis and visual acuity level. These participants then completed the NEI VFQ-25. The visual function (VF) and socioemotional (SE) subscales were psychometrically analysed in terms of item fit, targeting, internal consistency, dimensionality, and differential item functioning (DIF), using Rasch models. Criterion validity was examined based on associations between NEI VFQ person measures and recent visual acuity (VA) levels.ResultsNinety-nine participants recruited online from uveitis patient organizations (68 women, 31 men; mean age 50 ± 15 years; 46.5% self-reported receiving systematic therapy for uveitis, 0.6% NEI VFQ-25 missing data) were included. The mean difficulty of items was lower than the average person ability. None of the items demonstrated misfit to an extent that would induce noise into the measurement. The consistency metrics person reliability and person separation index of the subscales were 0.85 and 2.34 (NEI VFQ-VF), 0.86 and 2.52 (NEI VFQ-SE), respectively. There was no evidence of multidimensionality and none of the items showed DIF by gender. The differences between item and person measures were 1.44 (NEI VFQ-VF) and 1.03 (NEI VFQ-SE). NEI VFQ-25 person measures were significantly lower in participants with visual impairment (all p values ≤ 0.007).ConclusionRasch model-based scoring of the re-engineered NEI VFQ-25 demonstrates acceptable internal consistency, item fit and construct validity for assessing two key domains of quality of life in individuals self-reporting uveitis. The PROM was targeted at a higher level of difficulty than present in our heterogeneous sample.

Voretigene neparvovec for inherited retinal dystrophy due to RPE65 mutations: a scoping review of eligibility and treatment challenges from clinical trials to real practice

AbstractBiallelic mutations in the RPE65 gene affect nearly 8% of Leber Congenital Amaurosis and 2% of Retinitis Pigmentosa cases. Voretigene neparvovec (VN) is the first gene therapy approach approved for their treatment. To date, real life experience has demonstrated functional improvements following VN treatment, which are consistent with the clinical trials outcomes. However, there is currently no consensus on the characteristics for eligibility for VN treatment. We reviewed relevant literature to explore whether recommendations on patient eligibility can be extrapolated following VN marketing. We screened 166 papers through six research questions, following scoping reviews methodology, to investigate: (1) the clinical and genetic features considered in VN treatment eligibility; (2) the psychophysical tests and imaging modalities used in the pre-treatment and follow-up; (3) the potential correlations between visual function and retinal structure that can be used to define treatment impact on disease progression; (4) retinal degeneration; (5) the most advanced testing modalities; and (6) the impact of surgical procedure on treatment outcomes. Current gaps concerning patients’ eligibility in clinical settings, such as pre-treatment characteristics and outcomes are not consistently reported across the studies. No upper limit of retinal degeneration can be defined as the univocal factor in patient eligibility, although evidence suggested that the potential for function rescue is related to the preservation of photoreceptors before treatment. In general, paediatric patients retain more viable cells, present a less severe disease stage and show the highest potential for improvements, making them the most suitable candidates for treatment.

Defining the structure–function relationship of specific lesions in early and advanced age-related macular degeneration

The objective of this study is to define structure–function relationships of pathological lesions related to age-related macular degeneration (AMD) using microperimetry and multimodal retinal imaging. We conducted a cross-sectional study of 87 patients with AMD (30 eyes with early and intermediate AMD and 110 eyes with advanced AMD), compared to 33 normal controls (66 eyes) recruited from a single tertiary center. All participants had enface and cross-sectional optical coherence tomography (Heidelberg HRA-2), OCT angiography, color and infra-red (IR) fundus and microperimetry (MP) (Nidek MP-3) performed. Multimodal images were graded for specific AMD pathological lesions. A custom marking tool was used to demarcate lesion boundaries on corresponding enface IR images, and subsequently superimposed onto MP color fundus photographs with retinal sensitivity points (RSP). The resulting overlay was used to correlate pathological structural changes to zonal functional changes. Mean age of patients with early/intermediate AMD, advanced AMD and controls were 73(SD = 8.2), 70.8(SD = 8), and 65.4(SD = 7.7) years respectively. Mean retinal sensitivity (MRS) of both early/intermediate (23.1 dB; SD = 5.5) and advanced AMD (18.1 dB; SD = 7.8) eyes were significantly worse than controls (27.8 dB, SD = 4.3) (p < 0.01). Advanced AMD eyes had significantly more unstable fixation (70%; SD = 63.6), larger mean fixation area (3.9 mm2; SD = 3.0), and focal fixation point further away from the fovea (0.7 mm; SD = 0.8), than controls (29%; SD = 43.9; 2.6 mm2; SD = 1.9; 0.4 mm; SD = 0.3) (p ≤ 0.01). Notably, 22 fellow eyes of AMD eyes (25.7 dB; SD = 3.0), with no AMD lesions, still had lower MRS than controls (p = 0.04). For specific AMD-related lesions, end-stage changes such as fibrosis (5.5 dB, SD = 5.4 dB) and atrophy (6.2 dB, SD = 7.0 dB) had the lowest MRS; while drusen and pigment epithelial detachment (17.7 dB, SD = 8.0 dB) had the highest MRS. Peri-lesional areas (20.2 dB, SD = 7.6 dB) and surrounding structurally normal areas (22.2 dB, SD = 6.9 dB) of the retina with no AMD lesions still had lower MRS compared to controls (27.8 dB, SD = 4.3 dB) (p < 0.01). Our detailed topographic structure–function correlation identified specific AMD pathological changes associated with a poorer visual function. This can provide an added value to the assessment of visual function to optimize treatment outcomes to existing and potentially future novel therapies.

TFTG: A comprehensive database for human transcription factors and their targets

Transcription factors (TFs) are major contributors to gene transcription, especially in controlling cell-specific gene expression and disease occurrence and development. Uncovering the relationship between TFs and their target genes is critical to understanding the mechanism of action of TFs. With the development of high-throughput sequencing techniques, a large amount of TF-related data has accumulated, which can be used to identify their target genes. In this study, we developed TFTG (Transcription Factor and Target Genes) database (http://tf.liclab.net/TFTG), which aimed to provide a large number of available human TF-target gene resources by multiple strategies, besides performing a comprehensive functional and epigenetic annotations and regulatory analyses of TFs. We identified extensive available TF-target genes by collecting and processing TF-associated ChIP-seq datasets, perturbation RNA-seq datasets and motifs. We also obtained experimentally confirmed relationships between TF and target genes from available resources. Overall, the target genes of TFs were obtained through integrating the relevant data of various TFs as well as fourteen identification strategies. Meanwhile, TFTG was embedded with user-friendly search, analysis, browsing, downloading and visualization functions. TFTG is designed to be a convenient resource for exploring human TF-target gene regulations, which will be useful for most users in the TF and gene expression regulation research.

Effect of acupuncture for anisometropic amblyopia: A randomized clinical trial and potential mechanism: 针刺治疗屈光参差性弱视:一项随机对照试验及其潜在起效机制

ObjectiveTo evaluate the effect of acupuncture on anisometropic amblyopia (AA) and explore its potential mechanism for children with AA. MethodsSeventy-six children with monocular AA were randomized into a conventional treatment group and a combined treatment group of acupuncture and conventional treatment, with 38 patients in each group. In the conventional treatment group, on the base of patching regimen, the red flashing, grating and visual stimulation were delivered. Each approach lasted for 5 min per session and was given once every two days, three times a week, for 4 consecutive weeks. In the acupuncture-combined treatment group, on the base of the regimen of conventional treatment group, acupuncture was applied to Jingming (BL1), Cuanzhu (BL2), Fengchi (GB20) and Guangming (GB37), with needles retained for 20 min per session, once every two days, three times of intervention a week and for 4 consecutive weeks. Before and after treatment, the best corrected vision acuity (BCVA) was observed to evaluate the clinical effect in the two groups. Before treatment started, 15 patients with AA on left side were randomized selected from each group and the resting-state functional magnetic resonance imaging (rs-fMRI) was operated before and after treatment. Simultaneously, eight healthy children with normal visual acuity were recruited to be the normal control group and received one-time rs-fMRI scanning. Based on the activation likelihood estimation (ALE), the visual “what” pathway network was constructed. By analyzing the amplitude of low frequency fluctuation (ALFF) and the regional homogeneity (ReHo), the differences in the regional autonomous function activities in the key brain areas of the “what” pathway were compared among the three groups. Results(1) Clinical effect: After treatment, BCVA was (0.6 [0.5, 0.6]), higher than that (0.4 [0.3, 0.5]) before treatment, presenting the statistical difference (P < 0.05) in the conventional treatment group. BCVA was (0.6 [0.6, 0.8]), higher than that (0.4 [0.4, 0.5]) before treatment, presenting the statistical difference (P < 0.05) in the acupuncture-combined treatment group. BCVA in the acupuncture-combined treatment group was higher than that of the conventional treatment group (P < 0.05) after treatment. The total effective rate was 86.1% in the acupuncture-combined treatment group, higher than that (65.8%) of the conventional treatment group (P < 0.05). (2) Mechanism: ① ALFF: In comparison with the healthy control group, the ALFF in the primary visual cortex of the “what” pathway for AA children was reduced significantly (P < 0.05), and ALFF in the right fusiform gyrus and the right inferior temporal gyrus increased significantly when compared with the healthy children (P < 0.05). Compared with that before treatment, there was no significant difference in the brain areas of the “what” pathway after treatment in the conventional treatment group (P > 0.05). In the acupuncture-combined treatment group, ALFF in the right inferior occipital gyrus and the right fusiform gyrus of the “what” pathway increased after treatment when compared with that before treatment (P < 0.05). After treatment, in comparison with the conventional treatment group, there was no significant difference in the brain areas of “what” pathway in the acupuncture-combined treatment group (P > 0.05). ② ReHo: ReHo in the right inferior occipital gyrus, the right fusiform gyrus and the right inferior temporal gyrus in the “what” pathway was elevated significantly in AA children when compared with that in the healthy control group (P < 0.05). ReHo of the left inferior occipital gyrus and the left fusiform gyrus increased significantly after treatment when compared with that before treatment in the conventional treatment group (P<0.05). ReHo of the right inferior occipital gyrus, the left and the right fusiform gyrus increased significantly after treatment when compared with that before treatment in the acupuncture-combined treatment group (P < 0.05). After treatment, ReHo of the right inferior temporal gyrus in the “what” pathway in the acupuncture-combined treatment group was significantly higher than that of the conventional treatment group (P < 0.05). ConclusionThe acupuncture combined with conventional treatment improves BCVA and the total effective rate of AA children. The changes in the regional function activity of the brain areas within the “what” pathway were dominated by the compensatory increase of the autonomous activity in the occipital lobe (inferior occipital gyrus) and the temporal lobe (inferior temporal gyrus) in AA children. Both conventional treatment and acupuncture can enhance the intensity of autonomous function activities in the occipital lobe (inferior occipital gyrus) and the temporal lobe (fusiform gyrus / inferior temporal gyrus) in the “what” pathway so as to relieve visual impairment. ReHo in the inferior temporal gyrus in the acupuncture-combined treatment group was higher than that of the conventional treatment group and it suggests that the inferior temporal gyrus may be the key brain area to the improvement of visual function in the “what” pathway.

Central and peripheral contrast sensitivity in thyroid eye disease.

Assessment of central and peripheral contrast sensitivity (CS) in thyroid eye disease (TED) with and without dysthyroid optic neuropathy (DON). This cross-sectional study enrolled 33 eyes of 18 treatment-naïve TED patients and 18 age- and sex-matched healthy controls for comparative analysis. A detailed ophthalmic examination included visual acuity (VA), intraocular pressure measurement, slit-lamp biomicroscopy, and CS testing (central and four peripheral regions) using Spaeth-Richman Contrast Sensitivity test was done. The average age of TED patients was 47.17 ± 13.99 years and a female preponderance was noted (66.66%, n = 12). Twenty-five eyes (75.8%) were diagnosed as TED without DON, while eight eyes (24.2%) had DON. Nine eyes (27.2%) were in the active stage of disease and 29 eyes (87.8%) had proptosis. The difference in mean logMAR visual acuities between TED patients and controls was statistically insignificant (P = 0.189), but a significant difference was noted in central and total CS score (P < 0.001, Wilcoxon-Mann-Whitney test). On CS comparison between DON and non-DON eyes, a significant difference in average scores was noted in central and all peripheral areas (P < 0.05, Wilcoxon-Mann-Whitney test). With increasing clinical activity score, a statistically significant reduction was noted in CS in three out of four peripheral regions (Spearman correlation, P < 0.05). Visual function compromise can be detected in TED in the presence of intact VA, by testing CS. Peripheral CS deteriorates with increasing inflammation and in DON. Serial monitoring of both central and peripheral CS may help in diagnosing DON early.

Early diagnosis and treatment by newborn screening (NBS) or family history is associated with improved visual outcomes for long-chain 3-hydroxyacylCoA dehydrogenase deficiency (LCHADD) chorioretinopathy.

Long chain 3-hydroxyacyl-CoA dehydrogenase (LCHADD) is the only fatty acid oxidation disorder to develop a progressive chorioretinopathy resulting in vision loss; newborn screening (NBS) for this disorder began in the United States around 2004. We compared visual outcomes among 40 participants with LCHADD or trifunctional protein deficiency diagnosed symptomatically to those who were diagnosed via NBS or a family history. Participants completed ophthalmologic testing including measures of visual acuity, electroretinograms (ERG), fundal imaging, contrast sensitivity, and visual fields. Records were reviewed to document medical and treatment history. Twelve participants presented symptomatically with hypoglycemia, failure to thrive, liver dysfunction, cardiac arrest, or rhabdomyolysis. Twenty eight were diagnosed by NBS or due to a family history of LCHADD. Participants diagnosed symptomatically were older but had similar percent males and genotypes as those diagnosed by NBS. Treatment consisted of fasting avoidance, dietary long-chain fat restriction, MCT, C7, and/or carnitine supplementation. Visual acuity, rod- and cone-driven amplitudes on ERG, contrast sensitivity scores, and visual fields were all significantly worse among participants diagnosed symptomatically compared to NBS. In mixed-effects models, both age and presentation (symptomatic vs. NBS) were significant independent factors associated with visual outcomes. This suggests that visual outcomes were improved by NBS, but there was still lower visual function with advancing age in both groups. Early diagnosis and treatment by NBS is associated with improved visual outcomes and retinal function compared to participants who presented symptomatically. Despite the impact of early intervention, chorioretinopathy was greater with advancing age, highlighting the need for novel treatments.

Swan-feathers inspired smart-responsive sustainable carboxymethyl cellulose/polyvinyl alcohol based food packaging film for robustly integrated Intelligent and Active Packaging

The integration of advanced packaging technology with innovative multifunctional bio-based materials emerges as a promising next-generation strategy to tackle two enduring challenges in food storage technology: food spoilage and counterfeiting. Inspired by the superhydrophobic properties of swan feathers, this study developed a smart-responsive, sustainable food packaging film called C-CPQ using carboxymethyl cellulose (CMC) and polyvinyl alcohol (PVA). The as-prepared C-CPQ film exhibited remarkable hydrophobicity and water-vapor barrier properties owing to its novel design featuring an asymmetric bionic feather-like barbed texture, representing significant advancements in CMC/PVA-based packaging materials. Additionally, C-CPQ exhibited satisfactory mechanical strength, biodegradability, and film-forming capabilities. Notably, incorporating quercetin（QR） endowed C-CPQ with exceptional pH-sensing, fluorescence, antioxidant, UV-shielding, and antibacterial properties, enabling intelligent and active food packaging. Consequently, C-CPQ exhibited UV-stimulated photochromic characteristics and fatigue-resistant food anti-counterfeiting capabilities while extending food shelf life to 5 days, surpassing conventional PE packaging by 2 days. Moreover, the integration of smartphones enabled highly sensitive, rapid, and real-time visual monitoring of food degradation under natural light. The findings of this study present promising outcomes under real-world conditions, serving as a framework for the development of sustainable, high-performance modern food packaging with comprehensive real-time visual freshness monitoring, anti-counterfeiting, and preservation functionalities.

Associations Between Self-Reported Visual Difficulty, Age of Onset, and Cognitive Function Trajectories Among Chinese Older Adults.

Objectives: This study examined the association between self-reported visual difficulty and age-related cognitive declines among older Chinese adults and how the timing of visual difficulty onset plays a role in cognitive trajectories. Methods: Data were drawn from the 2011-2018 wave of the China Health and Retirement Longitudinal Study, involving 9974 respondents aged 60years or older (mean age 65.44years, range 60-101years). Results: At baseline, 14.16% respondents had self-reported visual difficulty. Growth curve models showed that Chinese older adults with visual difficulty experienced a faster decline in cognitive function compared to those without visual difficulty (β = -0.02, p < .01). Older adults who began experiencing visual difficulty between 61 and 75years of age had steeper cognitive declines compared to those with earlier or later onset (β = -0.05, p < .01). Discussion: Older adults with self-reported visual difficulty experience faster rates of cognitive decline. Future research should explore potential factors that underlie the association between onset timing of visual difficulty and cognitive function.

Optic nerve involvement in patients with Lyme neuroborreliosis: an electrophysiological study.

The aim of this neurophysiological study was to retrospectively analyze visual evoked potentials (VEPs) acquired during an examination for diagnosing optic nerve involvement in patients with Lyme neuroborreliosis (LNB). Attention was focused on LNB patients with peripheral facial palsy (PFP) and optic nerve involvement. A total of 241 Czech patients were classified as having probable/definite LNB (193/48); of these, 57 were younger than 40 years, with a median age of 26.3 years, and 184 were older than 40 years, with a median age of 58.8 years. All patients underwent pattern-reversal (PVEP) and motion-onset (MVEP) VEP examinations. Abnormal VEP results were observed in 150/241 patients and were noted more often in patients over 40 years (p = 0.008). Muscle/joint problems and paresthesia were observed to be significantly more common in patients older than 40 years (p = 0.002, p = 0.030), in contrast to headache and decreased visual acuity, which were seen more often in patients younger than 40 years (p = 0.001, p = 0.033). Peripheral facial palsy was diagnosed in 26/241 LNB patients. Among patients with PFP, VEP peak times above the laboratory limit was observed in 22 (84.6%) individuals. Monitoring of patients with PFP and pathological VEP showed that the adjustment of visual system function occurred in half of the patients in one to more years, in contrast to faster recovery from peripheral facial palsy within months in most patients. In LNB patients, VEP helps to increase sensitivity of an early diagnostic process.

Visual function loss in fungal sphenoid sinusitis: clinical characteristics and outcomes.

Potentially fatal fungal sphenoid sinusitis (FSS) causes visual damage. However, few studies have reported on its visual impairment and prognosis. Five hundred and eleven FSS patients with ocular complications treated at Beijing Tongren Hospital were recruited and clinical features and visual outcomes were determined. Thirty-two of the 511 patients (6%) had visual impairment, with 13 and 19 patients having invasive and noninvasive FSS, respectively. Eighteen patients (56.25%) had diabetes and 2 patient (6.25%) had long-term systemic use of antibiotics (n = 1) and corticosteroids (n = 1). All patients had visual impairment, which was more severe in invasive FSS than in noninvasive FSS. Bony wall defects and sclerosis were observed in 19 patients (59.38%), and 11 patients (34.38%) had microcalcification in their sphenoid sinusitis on computed tomography (CT). After a 5-year follow-up, three patients (9.38%) died. Patients with noninvasive FSS had a higher improvement rate in visual acuity than their counterparts. In the multivariate analysis, sphenoid sinus wall sclerosis on CT was associated with better visual prognosis. FSS can cause vision loss with persistent headaches, particularly in those with diabetes. CT showed the sphenoid sinus wall sclerosis, indicating a better visual prognosis in FSS with visual impairment.

PyOKR: A Semi-Automated Method for Quantifying Optokinetic Reflex Tracking Ability.

The study of behavioral responses to visual stimuli is a key component of understanding visual system function. One notable response is the optokinetic reflex (OKR), a highly conserved innate behavior necessary for image stabilization on the retina. The OKR provides a robust readout of image tracking ability and has been extensively studied to understand visual system circuitry and function in animals from different genetic backgrounds. The OKR consists of two phases: a slow tracking phase as the eye follows a stimulus to the edge of the visual plane and a compensatory fast phase saccade that resets the position of the eye in the orbit. Previous methods of tracking gain quantification, although reliable, are labor intensive and can be subjective or arbitrarily derived. To obtain more rapid and reproducible quantification of eye tracking ability, we have developed a novelsemi-automated analysis program, PyOKR, that allows for quantification of two-dimensional eye tracking motion in response to any directional stimulus, in addition to being adaptable to any type of video-oculography equipment. This method provides automated filtering, selection of slow tracking phases, modeling of vertical and horizontal eye vectors, quantification of eye movement gains relative to stimulus speed, and organization of resultant data into a usable spreadsheet for statistical and graphical comparisons. This quantitative and streamlined analysis pipeline, readily accessible via PyPI import, provides a fast and direct measurement of OKR responses, thereby facilitating the study of visual behavioral responses.

Flexible retinomorphic vision sensors with scotopic and photopic adaptation for a fully flexible neuromorphic machine vision system

AbstractBioinspired neuromorphic machine vision system (NMVS) that integrates retinomorphic sensing and neuromorphic computing into one monolithic system is regarded as the most promising architecture for visual perception. However, the large intensity range of natural lights and complex illumination conditions in actual scenarios always require the NMVS to dynamically adjust its sensitivity according to the environmental conditions, just like the visual adaptation function of the human retina. Although some opto‐sensors with scotopic or photopic adaption have been developed, NMVSs, especially fully flexible NMVSs, with both scotopic and photopic adaptation functions are rarely reported. Here we propose an ion‐modulation strategy to dynamically adjust the photosensitivity and time‐varying activation/inhibition characteristics depending on the illumination conditions, and develop a flexible ion‐modulated phototransistor array based on MoS2/graphdiyne heterostructure, which can execute both retinomorphic sensing and neuromorphic computing. By controlling the intercalated Li+ ions in graphdiyne, both scotopic and photopic adaptation functions are demonstrated successfully. A fully flexible NMVS consisting of front‐end retinomorphic vision sensors and a back‐end convolutional neural network is constructed based on the as‐fabricated 28 × 28 device array, demonstrating quite high recognition accuracies for both dim and bright images and robust flexibility. This effort for fully flexible and monolithic NMVS paves the way for its applications in wearable scenarios.

SiC@NiO Core-Shell Nanowire Networks-Based Optoelectronic Synapses for Neuromorphic Computing and Visual Systems at High Temperature.

1D nanowire networks, sharing similarities of structure, information transfer, and computation with biological neural networks, have emerged as a promising platform for neuromorphic systems. Based on brain-like structures of 1D nanowire networks, neuromorphic synaptic devices can overcome the von Neumann bottleneck, achieving intelligent high-efficient sensing and computing function with high information processing rates and low power consumption. Here, high-temperature neuromorphic synaptic devices based on SiC@NiO core-shell nanowire networks optoelectronic memristors (NNOMs) are developed. Experimental results demonstrate that NNOMs attain synaptic short/long-term plasticity and modulation plasticity under both electrical and optical stimulation, and exhibit advanced functions such as short/long-term memory and "learning-forgetting-relearning" under optical stimulation at both room temperature and 200°C. Based on the advanced functions under light stimulus, the constructed 5×3 optoelectronic synaptic array devices exhibit a stable visual memory function up to 200°C, which can be utilized to develop artificial visual systems. Additionally, when exposed to multiple electronic or optical stimuli, the NNOMs effectively replicate the principles of Pavlovian classical conditioning, achieving visual heterologous synaptic functionality and refining neural networks. Overall, with abundant synaptic characteristics and high-temperature thermal stability, these neuromorphic synaptic devices offer a promising route for advancing neuromorphic computing and visual systems.

Elderly-Centric Chromatics: Unraveling the Color Preferences and Visual Needs of the Elderly in Smart APP Interfaces

The survey found that many interactive interfaces of apps developed for the elderly on the market do not align with the visual characteristics of the elderly in terms of color configuration design. This mismatch greatly diminishes the usability and experience for elderly users. This research offers a meticulous analysis of user interface (UI) design for smart applications (APPs) specifically tailored for elderly users, focusing on enhancing visual functionality and protecting elderly users’ physical & mental health through scientifically configured colors. Against the backdrop of China’s aging population, this study implements the Hue, Saturation, and Lightness (HSL) model, and integrates methodologies from design, color theory, psychology, and statistics. Through visual simulation experiments, exhaustive questionnaires, and in-depth interviews, it was proposed that an APP interface color configuration design that meets the conditions of warm hue, high lightness, and medium saturation in the HSL model is most suitable for the elderly. The study also reveals a distinct aversion among the elderly toward colors with low lightness and specific cool hues.

The Logistical Backbone of Photoreceptor Cell Function: Complementary Mechanisms of Dietary Vitamin A Receptors and Rhodopsin Transporters.

In this review, we outline our current understanding of the mechanisms involved in the absorption, storage, and transport of dietary vitamin A to the eye, and the trafficking of rhodopsin protein to the photoreceptor outer segments, which encompasses the logistical backbone required for photoreceptor cell function. Two key mechanisms of this process are emphasized in this manuscript: ocular and systemic vitamin A membrane transporters, and rhodopsin transporters. Understanding the complementary mechanisms responsible for the generation and proper transport of the retinylidene protein to the photoreceptor outer segment will eventually shed light on the importance of genes encoded by these proteins, and their relationship on normal visual function and in the pathophysiology of retinal degenerative diseases.

[The impact of augmented reality glasses on human visual efficiency and digital eye fatigue].

Objective: To investigate the differences in reading efficiency and visual fatigue between the use of augmented reality (AR) glasses and laptops. Methods: A prospective self-controlled study was conducted. Healthy students from Capital Medical University who frequently engaged in long-term near work and used laptops and other digital display devices were recruited as subjects at Beijing Tongren Hospital, Capital Medical University between November 1 and November 15, 2023. LogMAR visual acuity, visual functions (accommodation, convergence, and fusion), and visual fatigue scores (Likert visual fatigue scale) of the participants were assessed. The order of using the laptop and AR glasses for each participant was determined by a coin toss. Reading efficiency (reading speed and error rate multiplied by the detection rate of incorrect numbers) with different devices for 10 minutes at the same time on different dates and visual fatigue scores after watching a 20-minute video were measured. Statistical analyses were performed using paired t-tests and Wilcoxon signed-rank tests. Results: A total of 20 eligible subjects were included, comprising 7 males and 13 females, with a mean age of (25.45±2.27) years. There was no significant change in binocular visual acuity before and after using AR glasses and laptops (both P>0.05). The reading speed and reading efficiency of using AR glasses [(34.03±9.25) and (29.19±7.62) digits/min, respectively] were significantly lower than those of using laptops [(39.43±10.36) and (35.67±9.87) digits/min, respectively] (t=4.36, P<0.001), while the difference in error detection rate was not statistically significant (t=1.29, P=0.213). There was no statistically significant difference in visual fatigue scores before watching videos with the two devices (Z=-0.71, P=0.480). However, the visual fatigue score after watching videos with AR glasses [(20.55±5.04) points] was significantly higher than that with laptops [16.50 (13.00, 19.75) points] (Z=-2.85, P=0.004). The visual fatigue scores after watching videos with both devices were significantly higher than before (P<0.05), with a more significant increase observed with AR glasses [(6.05±3.50) points] (Z=-3.41, P<0.001). Conclusion: Compared with using laptops, the reading speed and efficiency were lower, and the visual fatigue was more pronounced with the use of AR glasses at the current technical level. Further optimization and improvement of AR glasses are warranted.

Longitudinal Natural History Study of Visual Function in Bietti Crystalline Dystrophy: Implications for Early Intervention.

To delineate the natural history of visual function parameters over time in individuals with Bietti crystalline dystrophy. This was a single-center retrospective longitudinal cohort study. Participants (n = 29) with a clinical diagnosis of Bietti crystalline dystrophy who harbored two alleles of disease-causing variants of the cytochrome P450 family 4 subfamily V member 2 gene (CYP4V2) were enrolled. Best-corrected visual acuity (BCVA), visual field (VF), and full-field ERG (ffERG) at baseline and their changes during the follow-up period were evaluated. Annual progression rates were calculated using three methods. The mean age at the initial visit was 34.2 ± 7.5 years, with 5.9 ± 3.1 years follow-up. The annual progression rate from the longitudinal analysis using averaged individual progression rates was 0.079 logMAR units for BCVA, 1.14dB for mean defect (MD) value of VF, and -18.06µV and -5.45µV for the b-wave amplitudes of scotopic 3.0 ERG and photopic 3.0 ERG, respectively. Mixed-model linear regression revealed annual progression rates of 0.068 logMAR units, 0.86dB, -13.29µV, and -3.75µV, respectively. Cross-sectional progression rates from visual function versus age at baseline were 0.011 logMAR units, 0.47dB, -1.85 µV, and -1.07 µV, respectively, which were significantly slower than those from the longitudinal data. Interocular symmetries for the MD values of VF and ffERG were good. Annual BCVA, VF, and ffERG progression rates were rapid, emphasizing the need for regular follow-up and early intervention. The progression rate cannot be inferred accurately from cross-sectional data from patients of different ages.