Low Luminance Research Articles

Phase 1 Clinical Trial of Elamipretide in Dry Age-Related Macular Degeneration and Noncentral Geographic Atrophy: ReCLAIM NCGA Study.

PurposeAssess the safety, tolerability, and feasibility of subcutaneous administration of the mitochondrial-targeted drug elamipretide in patients with dry age-related macular degeneration (AMD) and noncentral geographic atrophy (NCGA) and to perform exploratory analyses of change in visual function.DesignPhase 1, single-center, open-label, 24-week clinical trial with preplanned NCGA cohort.ParticipantsAdults ≥ 55 years of age with dry AMD and NCGA.MethodsParticipants received subcutaneous elamipretide 40-mg daily; safety and tolerability assessed throughout. Ocular assessments included normal-luminance best-corrected visual acuity (BCVA), low-luminance BCVA (LLBCVA), normal-luminance binocular reading acuity (NLBRA), low-luminance binocular reading acuity (LLBRA), spectral-domain OCT, fundus autofluorescence (FAF), and patient self-reported function by low-luminance questionnaire (LLQ).Main Outcome MeasuresPrimary end point was safety and tolerability. Prespecified exploratory end-points included changes in BCVA, LLBCVA, NLBRA, LLBRA, geographic atrophy (GA) area, and LLQ.ResultsSubcutaneous elamipretide was highly feasible. All participants (n = 19) experienced 1 or more nonocular adverse events (AEs), but all AEs were either mild (73.7%) or moderate (26.3%); no serious AEs were noted. Two participants exited the study because of AEs (conversion to neovascular AMD, n = 1; intolerable injection site reaction, n = 1), 1 participant discontinued because of self-perceived lack of efficacy, and 1 participant chose not to continue with study visits. Among participants completing the study (n = 15), mean ± standard deviation (SD) change in BCVA from baseline to week 24 was +4.6 (5.1) letters (P = 0.0032), while mean change (SD) in LLBCVA was +5.4 ± 7.9 letters (P = 0.0245). Although minimal change in NLBRA occurred, mean ± SD change in LLBCVA was –0.52 ± 0.75 logarithm of the minimum angle of resolution units (P = 0.005). Mean ± SD change in GA area (square root transformation) from baseline to week 24 was 0.14 ± 0.08 mm by FAF and 0.13 ± 0.14 mm by OCT. Improvement was observed in LLQ for dim light reading and general dim light vision.ConclusionsElamipretide seems to be well tolerated without serious AEs in patients with dry AMD and NCGA. Exploratory analyses demonstrated possible positive effect on visual function, particularly under low luminance. A Phase 2b trial is underway to evaluate elamipretide further in dry AMD and NCGA.

Design of white tandem organic light‐emitting diodes for full‐color microdisplay with high current efficiency and high color gamut

Microdisplays based on organic light-emitting diodes (OLEDs) have a small form factor, and this can be a great advantage when applied to augmented reality and virtual reality devices. In addition, a high-resolution microdisplay of 3000 ppi or more can be achieved when applying a white OLED structure and a color filter. However, low luminance is the weakness of an OLED-based microdisplay as compared with other microdisplay technologies. By applying a tandem structure consisting of two separate emission layers, the efficiency of the OLED device is increased, and higher luminance can be achieved. The efficiency and white spectrum of the OLED device are affected by the position of the emitting layer in the tandem structure and calculated via optical simulation. Each white OLED device with optimized efficiency is fabricated according to the position of the emitting layer, and red, green, and blue spectrum and efficiency are confirmed after passing through color filters. The optimized white OLED device with color filters reaches 97.8% of the National Television Standards Committee standard.

Edge Directed Radial Basis Function based Interpolation Towards PCA based PAN-sharpening

ABSTRACT In this research, we proposed a new PAN-sharpening algorithm by using edge-directed Gaussian Radial Basis Function (RBF) and Principal Component Analysis (PCA). Up-scaling is a procedure to upgrade the spectral data of a Low Resolution (LR) Multi Spectral (MS) imagery. Non-linear up-scaling methods generate fewer artefacts in the interpolated image as they are edge-adaptive in nature. Adaptive interpolation techniques consider different features of an image during up-scaling. These techniques are proven efficient compared with non-adaptive methods. However, they may generate distorted output in fine-textured areas and can have lower luminance information. We consider the Laplacian of Gaussian (LoG) or Marr-Hildreth edge detection operator to preserve missing structure and luminance information. It generates smooth edges by minimizing artefacts in the interpolated image. We have considered multi-source and multi-sensor datasets obtained from LISS-IV, CATROSAT-I, and Quickbird to perform all experiments. We have carried out a broad quantitative and subjective assessment and comparison of the proposed algorithm with the standard and cutting-edge methods.

Comparison of Visual Function Tests in Intermediate Age-Related Macular Degeneration.

PurposeIdentifying the most sensitive functional measure in intermediate age-related macular degeneration (iAMD) could help select an appropriate test for monitoring disease progression and evaluating the efficacy of novel interventions for the early stages of AMD. The purpose of the study was to determine which commonly used visual function test is the most discriminatory when comparing individuals with iAMD to normal participants.MethodsIn this prospective observational study, iAMD cases and healthy controls underwent visual function testing (best corrected visual acuity (BCVA), low luminance visual acuity (LLVA), mesopic microperimetry, dark adaptation, and scotopic perimetry following photobleach), clinical eye examination, and multimodal retinal imaging in a single study visit. The data of each functional parameter were converted into z-score so that all the parameters had a common scale to allow a direct comparison between different functional parameters.ResultsForty-eight subjects (23 normal control, 25 iAMD) participated. Although all five parameters showed a significant reduction in function in iAMD eyes compared to controls (P ≤ 0.003), the rod intercept time (RIT) detected the greatest reduction in function followed by the scotopic sensitivity, mesopic sensitivity, BCVA, and LLVA, with the absolute mean z-score of 4.5, 2.2, 1.0, 1.0, and 1.2, respectively.ConclusionsAmong the five visual function parameters commonly used, RIT is the most discriminatory functional parameter in the early stages of AMD.Translational RelevanceThe RIT could be considered for assessing visual function and evaluating efficacy of novel interventions aimed at improving retinal function in eyes with early stages of AMD.

State-dependent TMS effects in the visual cortex after visual adaptation: A combined TMS–EEG study

ObjectiveThe impact of transcranial magnetic stimulation (TMS) has been shown to depend on the initial brain state of the stimulated cortical region. This observation has led to the development of paradigms that aim to enhance the specificity of TMS effects by using visual/luminance adaptation to modulate brain state prior to the application of TMS. However, the neural basis of interactions between TMS and adaptation is unknown. Here, we examined these interactions by using electroencephalography (EEG) to measure the impact of TMS over the visual cortex after luminance adaptation. MethodsSingle-pulses of neuronavigated TMS (nTMS) were applied at two different intensities over the left visual cortex after adaptation to either high or low luminance. We then analyzed the effects of adaptation on the global and local cortical excitability. ResultsThe analysis revealed a significant interaction between the TMS-evoked responses and the adaptation condition. In particular, when nTMS was applied with high intensity, the evoked responses were larger after adaptation to high than low luminance. ConclusionThis result provides the first neural evidence on the interaction between TMS with visual adaptation. SignificanceTMS can activate neurons differentially as a function of their adaptation state.

Night Vision and Carotenoids (NVC): A Randomized Placebo Controlled Clinical Trial on Effects of Carotenoid Supplementation on Night Vision in Older Adults.

Twilight and low luminance levels are visually challenging environments for the elderly, especially when driving at night. Carotenoid rich diets are known to increase macular pigment optical density (MPOD), which in turn leads to an improvement in visual function. It is not known whether augmenting MPOD can lead to a decrease in vision related night driving difficulties. Additionally, it is unknown if carotenoid supplementation provides additional measurable benefits to one’s useful field of view (UFOV) along with a decreased composite crash risk score. The aim of the study was to evaluate changes in night vision function and UFOV in individuals that took carotenoid vitamin supplements for a six-month period compared to a placebo group. Methods: A prospective, randomized, double-blind, six-month trial of a 14 mg zeaxanthin/7 mg lutein-based supplement was carried out. Participants were randomized into active or placebo group (approx 2:1). Results: n = 33 participants (26 males/7 females) participated with 93% capsule intake compliance in the supplemented group (n = 24) and placebo group (n = 9). MPOD (mean/standard error SE) in the active group increased in the Right eye from 0.35 density units (du)/0.04 SE to 0.41 du/0.05 SE; p < 0.001 and in the Left eye from 0.35 du/0.05 SE to 0.37 du, p > 0.05). The supplemented group showed significant improvements in contrast sensitivity with glare in both eyes with improvements in LogMAR scores of 0.147 and 0.149, respectively (p = 0.02 and 0.01, respectively), monocularly tested glare recovery time improved 2.76 and 2.54 s, respectively, (p = 0.008 and p = 0.02), and we also noted a decreased preferred luminance required to complete visual tasks (p = 0.02 and 0.03). Improvements in UFOV scores of divided attention (p < 0.001) and improved composite crash risk score (p = 0.004) were seen in the supplemented group. The placebo group remained unchanged. Conclusions: The NVC demonstrates that augmenting MPOD in individuals with difficulty in night vision showed measurable benefits in numerous visual functions that are important for night vision driving in this small sample RCT. Additionally, we observed an improvement in UFOV divided attention test scores and decreased composite risk scores.

Nearby contours abolish the binocular advantage

That binocular viewing confers an advantage over monocular viewing for detecting isolated low luminance or low contrast objects, has been known for well over a century; however, the processes involved in combining the images from the two eyes are still not fully understood. Importantly, in natural vision, objects are rarely isolated but appear in context. It is well known that nearby contours can either facilitate or suppress detection, depending on their distance from the target and the global configuration. Here we report that at close distances collinear (but not orthogonal) flanking contours suppress detection more under binocular compared to monocular viewing, thus completely abolishing the binocular advantage, both at threshold and suprathreshold levels. In contrast, more distant flankers facilitate both monocular and binocular detection, preserving a binocular advantage up to about four times the detection threshold. Our results for monocular and binocular viewing, for threshold contrast discrimination without nearby flankers, can be explained by a gain control model with uncertainty and internal multiplicative noise adding additional constraints on detection. However, in context with nearby flankers, both contrast detection threshold and suprathreshold contrast appearance matching require the addition of both target-to-target and flank-to-target interactions occurring before the site of binocular combination. To test an alternative model, in which the interactions occur after the site of binocular combination, we performed a dichoptic contrast matching experiment, with the target presented to one eye, and the flanks to the other eye. The two models make very different predictions for abutting flanks under dichoptic conditions. Interactions after the combination site predict that the perceived contrast of the flanked target will be strongly suppressed, while interactions before the site predict the perceived contrast will be more or less veridical. The data are consistent with the latter model, strongly suggesting that the interactions take place before the site of binocular combination.

Helmholtz Versus Haute Couture: How Horizontal Stripes and Dark Clothes Make You Look Thinner.

In Helmholtz’s illusion, a square with horizontal stripes appears taller than an identical square with vertical stripes. This effect has also been observed in experiments with human stimuli, where a human figure wearing a dress with horizontal stripes appears thinner than a drawing clad in vertical stripes. These findings do not agree with the common belief that clothes with horizontal stripes make someone appear wider, neither do they disentangle whether the horizontal or vertical stripes account for the thinning effect. In the present study, we focused on the effect of horizontal stripes in clothes comparing horizontal stripes against no-stripes (not against vertical; Experiments 1 and 2), using photos of a real-life female model, and controlling for the average luminance of the stripes (Experiment 2). Results showed that horizontal stripes and lower luminance have—independently—a small-to-moderate thinning effect on the perceived size of the body, and the effect is larger when the two variables are combined. In Experiment 3, we further show that the thinning effect due to the luminance of the dress is enhanced when the general background gets darker.

Optimal flickering light stimulation for entraining gamma waves in the human brain

Although light flickering at 40 Hz reduced Alzheimer’s disease (AD) pathologies in mice by entraining gamma waves, it failed to reduce cerebral amyloid burden in a study on six patients with AD or mild cognitive impairment. We investigated the optimal color, intensity, and frequency of the flickering light stimulus for entraining gamma waves in young adults. We compared the event-related synchronization (ERS) values of entrained gamma waves between four different light colors (white, red, green, and blue) in the first experiment and four different luminance intensities in the second experiment. In both experiments, we compared the ERS values of entrained gamma waves between 10 different flickering frequencies from 32 to 50 Hz. We also examined the severity of six adverse effects in both experiments. We compared the propagation of gamma waves in the visual cortex to other brain regions between different luminance intensities and flickering frequencies. We found that red light entrained gamma waves most effectively, followed by white light. Lights of higher luminance intensities (700 and 400 cd/m2) entrained stronger gamma waves than those of lower luminance intensities (100 and 10 cd/m2). Lights flickering at 34–38 Hz entrained stronger and more widely spread beyond the visual cortex than those flickering at 40–50 Hz. Light of 700 cd/m2 resulted in more moderate-to-severe adverse effects than those of other luminance intensities. In humans, 400 cd/m2 white light flickering at 34–38 Hz was most optimal for gamma entrainment.

Visual Dysfunction and Structural Correlates in Sorsby Fundus Dystrophy

To elucidate morphological determinants of rod and cone dysfunction in Sorsby fundus dystrophy (SFD), and to systematically compare visual function tests for interventional trials. Prospective cross-sectional study. Patients with SFD (n=16) and controls (n=20) underwent visual function testing (best-corrected visual acuity [BCVA] and low luminance visual acuity [LLVA], contrast sensitivity, mesopic and dark-adapted (DA) fundus-controlled perimetry [FCP], rod-mediated dark adaptation [RMDA]), and multimodal imaging. Vision-related quality of life was evaluated. FCP and RMDA thresholds were analyzed using mixed models and structure-function correlation using machine learning (ML). Longitudinal data of 1 patient with high-dose vitamin A supplementation were available. Although photopic BCVA was normative in SFD, LLVA was impaired (0.30 LogMAR [0.20; 0.45] vs 0.20 LogMAR [0.03; 0.28], P < .05). Scotopic visual function exhibited a delayed rod-intercept time (21 minutes [12.15; 21] vs 4.05 minutes [3.22; 5.36], P < .001), and marked DA cyan mean sensitivity loss (-11.80 dB [-3.47; -19.85]), paralleled by a reduced vision-related quality of life. ML-based structure-function correlation allowed prediction of mesopic, DA cyan, and red sensitivity with high accuracy (cross-validated mean absolute error: 4.36, 7.77, and 5.31 dB, respectively), whereas RMDA could be slowed even in the absence of fundus alterations on multimodal imaging. After high-dose vitamin A supplementation, RMDA and DA thresholds improved markedly. Patients with SFD exhibit severely impaired scotopic visual function even in the absence of funduscopic alterations on multimodal imaging. In contrast to BCVA, scotopic visual function tests are suitable to quantify dysfunction in the early stages. Improvement of scotopic dysfunction after (off-label) high-dose vitamin A intake, as observed in one patient in our study, is compatible with the hypothesized local deficiency of vitamin A secondary to Bruch's membrane alterations.

5.1: Invited Paper: Preferred LCD and OLED Luminance In Daily Tasks Is Affected By Ambient Lighting and Age

Preferred display luminance varies in relation to visual demand, image contrast, and ambient illumination. OLED is known to have a higher contrast ratio at a lower luminance output, and is more energy efficient at a lower luminance compared to LCD. To assess the preferred luminance in OLED and LCD in varied ambient lighting conditions, 48 young and older subjects were asked to perform reading, spreadsheet search, and videos viewing. They pre‐selected a preferred luminance level and then reassessed it after a 2‐min session for these tasks to arrive at a preferred luminance. Results show OLED has a lower preferred luminance compared to LCD, especially in bright viewing. Older viewers maintained a similarly higher luminance preference in dark and bright conditions, whereas young viewers preferred a lower luminance in dark viewing but not bright viewing. Conversely, pupil size was smaller in older viewers and in the bright condition. Image qualities were also better for the OLED, except brightness range and color vividness. These outcomes suggest lower OLED luminance is beneficial across age groups, ambient lighting, and task types, and can reduce energy consumption.

Space-luminance crossmodal correspondences in domestic chicks

Crossmodal correspondences are spontaneous associations of non-redundant information across different modalities. Infants and some non-human animals (i.e., chimpanzees, rhesus monkeys, and dogs) showed crossmodal correspondences like adult humans, suggesting a shared origin (at least among mammals) of such a phenomenon.Here we investigate visual-spatial crossmodal correspondences in a precocial avian species, i.e., the domestic chicken. Three-day-old chicks (n = 40) were presented with two (one in the left and one in the right hemispace of an arena) identical panels, either dyed black (low luminance) or white (high luminance). Chicks could circumnavigate either panel to obtain a food reward. Akin to humans, they preferentially chose the left side when presented with black panels and the right side when presented with white panels. The control group (n = 39), tested with grey panels, showed no spatial preference. In light of our results, we discuss crossmodal correspondences in terms of an early available mechanism widespread across different species.

Is white the right light for the clinical electrooculogram?

To investigate if a lower luminance monochromatic LED stimulus could be used as an alternative to a high luminance white light for the clinical electrooculogram. Clinical electrooculograms were recorded in color normal participants (N = 23) aged 22.6 ± 1.2years, 7 male and 16 female using the standard 100cd.m-2 white illuminant and four monochromatic LEDs with peak wavelengths of 448, 534, 596 and 634nm at 30cd.m-2. Pupils were dilated and there was a 30cd.m-2pre-adaptation to white light for 2min followed by 15min dark adaptation and 20min recording in the light stimulus using a Ganzfeld stimulator. The normalized LP:DTratio for the short wavelength LED (448nm) was equivalent in amplitude and timing to the ISCEV standard EOG (p = .99). The LP:DTratio for the white (100cd.m-2) and 448nm (30cd.m-2) were (median ± SEM): 2.49 ± .11 and 2.47 ± .11. The time to light-rise peak was also equivalent being 9.0 ± .2 and 8.0 ± .4min (p = .54). Consideration may be given to using a short wavelength monochromatic stimulus that is more comfortable for the subject than the current 100cd.m-2 illuminant.

PRO45 Health-Related Quality of Life in Patients with Age-Related Macular Degeneration and Their Caregivers: A Review of Evidence

Patients with age-related macular degeneration (AMD) experience blurred vision which progresses to blindness with age. This condition negatively impacts patient’s health-related quality of life (HRQoL) and also increases caregiver burden. The objective is to summarize HRQoL studies in AMD including a description of the instruments and their psychometric properties. The literature search was conducted from 2015 till January 2021 using two electronic databases—PubMed and EBSCOhost. The search strategy included all international studies that reported the use of HRQoL instruments and their psychometric properties in adult AMD population. Clinical studies, economic evaluations, reviews, and commentaries were excluded from the review. A total of seven studies were identified that assessed HRQoL in AMD. Only one study was conducted in the United States and the rest were from six different countries. Different disease classifications were utilized—wet and dry AMD (n=2) and early, intermediate, and late-stage AMD (n=3). A few studies (n=5) utilized unilateral or bilateral patients. Disease-specific and generic instruments utilized in patients and caregivers included the National Eye Institute 25-Item Visual Function Questionnaire (NEI VFG-25), Visual Function Questionnaire (VFQ), Impact Vision Impairment Questionnaire (IVI), Macular Disease Dependent Quality of Life Questionnaire (MacDQoL), Low Luminance Deficit LLD, EuroQoL-5D (EQ-5D), Short Form-12 (SF-12), and Caregiver Reaction Assessment (CRA) scale. Majority of studies (n=5) utilized NEI VFG-25 instrument and only one study reported the psychometric properties of the HRQoL instrument (IVI). One study reported the impact of AMD on caregiver burden and two studies reported the effect of ranibizumab on HRQoL. The importance of measuring HRQoL in patients and caregivers in AMD has been reported in several countries. The assessment of physical, psychological, and emotional aspects of AMD can assist providers and policymakers in better understanding the needs and providing optimal care to both patients and caregivers.

Subliminal temporal integration of linguistic information under discontinuous flash suppression.

Whether unconscious complex visual information integration occurs over time remains largely unknown and highly controversial. Previous studies have tended to use a combination of strong masking or suppression and a weak stimulus signal (e.g., low luminance), resulting in a low signal-to-noise ratio during unconscious stimulus presentation. To lengthen the stimulus exposure, we introduced intermittent presentation into interocular suppression. This discontinuous suppression allowed us to insert a word during each suppression period and deliver multiple words over time unconsciously. We found that, after participants received the subliminal context, they responded faster to a syntactically incongruent target word in a lexical decision task. We later replicated the finding in a separate experiment where participants exhibited chance performance on locating the subliminal context. These results confirmed that the sentential context was both subjectively and objectively subliminal. Critically, the effect disappeared when the context was disrupted by presenting only partial sentences or sentences with a reversed word order. These control experiments showed that the effect was not merely driven by word–word association but instead required integration over multiple words in the correct order. These findings support the possibility of unconscious high-level, complex information integration.

Thermally Activated Delayed Fluorescence in Commercially Available Materials for Solution-Process Exciplex OLEDs.

Organic light-emitting diodes (OLEDs) have developed rapidly in recent years. Thermally activated delayed fluorescent (TADF) molecules open a path to increase exciton collection efficiency from 25% to 100%, and the solution process provides an alternative technology to achieve lower cost OLEDs more easily. To develop commercial materials as exciplex hosts for high-performance and solution-processed OLEDs, we attempted to use 4,4′-cyclohexylidenebis[N,N-bis(4-methylphenyl)benzenamine (TAPC), poly(9-vinylcarbazole) (PVK), N,N′-Di(1-naphthyl)-N,N′-diphenyl-(1,1′-biphenyl)-4,4′-diamine (NPB), and poly(N,N’-bis-4-butylphenyl-N,N’-bisphenyl)benzidine (Poly-TPD) as the donors and 2,4,6-tris[3-(diphenylphosphinyl)phenyl]-1,3,5-triazine (POT2T) as the acceptor to obtain the TADF effect. All donors and the acceptor were purchased from chemical suppliers. Our work shows that excellent TADF properties and high-efficiency exciplex OLEDs with low turn-on voltage and high luminance can be achieved with a simple combination of commercial materials.

Impact of low luminance conditions on quality of life for the visually impaired: development of the Low Luminance Questionnaire Japanese version.

This study aimed to develop a Japanese version of the Low Luminance Questionnaire (LLQ-J) and to evaluate its reliability and validity. Cross-sectional study. LLQ-J was developed by standardized methods. A total of 101 patients comprising 55 with age-related macular degeneration, 25 with glaucoma, 15 with regressed proliferative diabetic retinopathy, and 6 with retinitis pigmentosa were included in this study. The patients completed the LLQ-J and Japanese version of the visual function Questionnaire-25 (VFQ-25). Using the LLQ-J data, floor and ceiling effects were computed. To examine internal consistency, some patients completed the LLQ-J a second time 2-4weeks later and the data were analyzed for Cronbach's alpha and intra-class correlation coefficients (ICCs). Best-corrected visual acuity (BCVA) and low luminance visual acuity (LLVA) were measured, and low-luminance deficit (LLD) was calculated. Criterion validity was also tested. No ceiling or floor effects were present in the LLQ-J data. Cronbach's alfa was 0.88, and ICCs were higher than 0.70 for all subscales. Moderate to high correlation was observed between LLQ-J and VFQ-25 (p < 0.01), confirming concurrent validity. "General dim lighting" and "Peripheral vision" were significantly associated with LLVA in the better eye (p < 0.05). "Mobility", "General dim lighting" and "Peripheral vision" were significantly associated with LLD (p < 0.05). "Emotional distress" was significantly associated with BCVA in the worse eye (p < 0.05). No subscales were associated with BCVA of the better eye. The LLQ-J is a valid and reliable questionnaire for assessing QOL under low luminance conditions.

Assessing Photoreceptor Status in Retinal Dystrophies: From High-Resolution Imaging to Functional Vision

PurposeTo describe the value of integrating phenotype/genotype data, disease staging, and evaluation of functional vision in patient-centered management of retinal dystrophies.Methods(1) Cross-sectional structure-function and retrospective longitudinal studies to assess the correlations between standard fundus autofluorescence (FAF), optical coherence tomography, visual acuity (VA), and perimetry (visual field [VF]) examinations to evaluate photoreceptor functional loss in a cohort of patients with rod-cone dystrophy (RCD); (2) flood-illumination adaptive optics (FIAO) imaging focusing on photoreceptor misalignment and orientation of outer segments; and (3) evaluation of the impact of visual impairment in daily life activities, based on functional (visual and mobility) vision assessment in a naturalistic environment in visually impaired subjects with RCD and subjects treated with LuxturnaⓇ for RPE65-related Leber congenital amaurosis before and after therapy.ResultsThe results of the cross-sectional transversal study showed that (1) VA and macular sensitivity were weakly correlated with the structural variables; and (2) functional impairment (VF) was correlated with reduction of anatomical markers of photoreceptor structure and increased width of autofluorescent ring. The dimensions of the ring of increased FAF evolved faster. Other criteria that differed among groups were the lengths of the ellipsoid zone, the external limiting membrane, and the foveal thickness. FIAO revealed a variety of phenotypes: paradoxical visibility of foveal cones; heterogeneous brightness of cones; dim, inner segment–like, and RPE-like mosaic. Directional illumination by varying orientation of incident light (Stiles-Crawford effect) and the amount of side illumination (gaze-dependent imaging) affected photoreceptor visibility. Mobility assessment under different lighting conditions showed correlation with VF, VA, contrast sensitivity (CS), and dark adaptation, with different predictive values depending on mobility study paradigms and illumination level. At high illumination level (235 lux), VF was a predictor for all mobility performance models. Under low illumination (1 and 2 lux), VF was the most significant predictor of mobility performance variables, while CS best explained the number of collisions and segments. In subjects treated with LuxturnaⓇ, a very favorable impact on travel speed and reduction in the number of collisions, especially at low luminance, was observable 6 months following injection, in both children and adults.ConclusionsOur results suggest the benefit of development and implementation of quantitative and reproducible tools to evaluate the status of photoreceptors and the impact of both visual impairment and novel therapies in real-life conditions. NOTE: Publication of this article is sponsored by the American Ophthalmological Society.

MoOx-Si heterojunction with wide-band-gap MoOx contact layer in the application of low-intensity visible-light sensing

The MoOx-Si heterojunction was demonstrated with MoOx as hole contact layer for visible-light sensor application. The α-MoO3 polycrystalline layer was fabricated with high band gap (~2.91 eV) and high transmittance (>75%). The microscale MoOx-Si heterojunction sensor displays great photocurrent under white-light illumination (~10−11 A at extremely low luminance of 40 lx). The rejection ratio is 103 at 1240 lx. Additionally, the MoOx-Si heterojunction sensor shows great repeatability and stability at remarkable low operation voltage (−0.5 V–0 V). The device displays fast recovery with short response time and decay time (both < 0.036 s). The performance indicates the MoOx-Si heterojunction could be a promising device for low-intensity visible-light sensing application.

The effect of low light levels on postural stability in older adults with age-related macular degeneration.

To investigate the effect of low light levels on postural stability in older adults with and without age-related macular degeneration (AMD). Participants included 28 older adults [14 with AMD (mean age ± S.D., 83.4±6.7years) and 14 controls with normal vision (74.6±3.3years)]. Postural stability was assessed with eyes open on both a firm and foam surface under four lighting conditions in a randomised order: photopic (~436lux, vertically at the eye), sudden reduction to mesopic (~436 to ~1lux), adapted mesopic (~1lux) and adapted mesopic with a light emitting diode (LED) door frame lighting system (~1.3lux), using the root mean square (RMS) of the centre of pressure measures derived from an electronic force plate in the anterior-posterior (AP) and medio-lateral (ML) directions. Visual function was assessed binocularly (visual acuity, contrast sensitivity and visual fields), physical function was assessed using standardised measures (sit-to-stand, grip strength and the timed walk test) and self-reported difficulties under low light levels were recorded using the Low Luminance Questionnaire. Data were analysed using linear mixed models. For all participants, low light levels significantly increased postural sway on the foam surface in the AP (p=0.01) but not ML (p=0.80) direction, but had no effect on postural stability on the firm surface. On the foam surface, while AP-RMS sway was significantly greater in the sudden (p<0.001) and adapted (p=0.02) mesopic compared to the photopic condition, sway for the adapted mesopic with the LED lighting system was not significantly different to the photopic condition (p=0.20). On the foam surface, AP-RMS (p=0.02) and ML-RMS (p<0.001) sway were significantly greater in the AMD compared to the control group. None of the measures of visual function was significantly associated with AP- or ML-RMS sway. On the foam surface, low light levels significantly reduced postural stability in older adults with and without AMD, and postural stability was significantly reduced for the AMD group compared to controls, regardless of light level. Importantly, the LED lighting system reduced sway under mesopic conditions, which was not significantly greater than that measured under photopic conditions in either group. These findings have important implications for enhancing the visual environment for older adults with and without AMD to improve postural stability and reduce the risk of falls in low lighting environments.