Improving Understanding of Visual Snow by Quantifying its Appearance and Effect on Vision.

Purpose: Visual snow is the hallmark of the neurological condition visual snow syndrome (VSS) but the characteristics of the visual snow percept remain poorly defined. This study aimed to quantify its appearance, interobserver variability, and effect on measured visual performance and self-reported visual quality. Methods: Twenty-three participants with VSS estimated their visual snow dot size, separation, luminance, and flicker rate by matching to a simulation. To assess whether visual snow masks vision, we compared pattern discrimination thresholds for textures that were similar in spatial scale to visual snow as well as more coarse than visual snow, in participants with VSS, and with and without external noise simulating visual snow in 23 controls. Results: Mean and 95% confidence intervals for visual snow appearance were: size (6.0, 5.8-6.3 arcseconds), separation (2.0, 1.7-2.3 arcmin), luminance (72.4, 58.1-86.8 cd/m2), and flicker rate (25.8, 18.9-32.8 frames per image at 120 hertz [Hz]). Participants with finer dot spacing estimates also reported greater visibility of their visual snow (τb = -0.41, 95% confidence interval [CI] = -0.62 to -0.13, P = 0.01). In controls, adding simulated fine-scale visual snow to textures increased thresholds for fine but not coarse textures (F(1, 22) = 4.98, P = 0.036, ηp2 = 0.19). In VSS, thresholds for fine and coarse textures were similar (t(22) = 0.54, P = 0.60), suggesting that inherent visual snow does not act like external noise in controls. Conclusions: Our quantitative estimates of visual snow constrain its likely neural origins, may aid differential diagnosis, and inform future investigations of how it affects vision. Methods to quantify visual snow are needed for evaluation of potential treatments.

Taking climate-smart governance to the high seas.

Comprehensive spatial planning in international waters is key to achieving ocean sustainability.

Severe 21st-century ocean acidification in Antarctic Marine Protected Areas.

Antarctic coastal waters are home to several established or proposed Marine Protected Areas (MPAs) supporting exceptional biodiversity. Despite being threatened by anthropogenic climate change, uncertainties remain surrounding the future ocean acidification (OA) of these waters. Here we present 21st-century projections of OA in Antarctic MPAs under four emission scenarios using a high-resolution ocean-sea ice-biogeochemistry model with realistic ice-shelf geometry. By 2100, we project pH declines of up to 0.36 (total scale) for the top 200 m. Vigorous vertical mixing of anthropogenic carbon produces severe OA throughout the water column in coastal waters of proposed and existing MPAs. Consequently, end-of-century aragonite undersaturation is ubiquitous under the three highest emission scenarios. Given the cumulative threat to marine ecosystems by environmental change and activities such as fishing, our findings call for strong emission-mitigation efforts and further management strategies to reduce pressures on ecosystems, such as the continuation and expansion of Antarctic MPAs.

Protect global values of the Southern Ocean ecosystem.

Climate change and fishing present dual threats.

Lessons from bright-spots for advancing knowledge exchange at the interface of marine science and policy.

Evidence-informed decision-making is in increasing demand given growing pressures on marine environments. A way to facilitate this is by knowledge exchange among marine scientists and decision-makers. While many barriers are reported in the literature, there are also examples whereby research has successfully informed marine decision-making (i.e., 'bright-spots'). Here, we identify and analyze 25 bright-spots from a wide range of marine fields, contexts, and locations to provide insights into how to improve knowledge exchange at the interface of marine science and policy. Through qualitative surveys we investigate what initiated the bright-spots, their goals, and approaches to knowledge exchange. We also seek to identify what outcomes/impacts have been achieved, the enablers of success, and what lessons can be learnt to guide future knowledge exchange efforts. Results show that a diversity of approaches were used for knowledge exchange, from consultative engagement to genuine knowledge co-production. We show that diverse successes at the interface of marine science and policy are achievable and include impacts on policy, people, and governance. Such successes were enabled by factors related to the actors, processes, support, context, and timing. For example, the importance of involving diverse actors and managing positive relationships is a key lesson for success. However, enabling routine success will require: 1) transforming the ways in which we train scientists to include a greater focus on interpersonal skills, 2) institutionalizing and supporting knowledge exchange activities in organizational agendas, 3) conceptualizing and implementing broader research impact metrics, and 4) transforming funding mechanisms to focus on need-based interventions, impact planning, and an acknowledgement of the required time and effort that underpin knowledge exchange activities.

Visual contrast perception in visual snow syndrome reveals abnormal neural gain but not neural noise.

Visual snow syndrome is a neurological condition characterized by a persistent visual disturbance, visual snow, in conjunction with additional visual symptoms. Cortical hyperexcitability is a potential pathophysiological mechanism, which could be explained by increased gain in neural responses to visual input. Alternatively, neural noise in the visual pathway could be abnormally elevated. We assessed these two potential competing neural mechanisms in our studies of visual contrast perception. Cortical hyperexcitation also occurs in migraine, which commonly co-occurs with visual snow syndrome. Therefore, to determine whether the effect of visual snow syndrome can be distinguished from interictal migraine, we recruited four participant groups: controls, migraine alone, visual snow syndrome alone and visual snow syndrome with migraine. In the first experiment, we estimated internal noise in 20 controls, 21 migraine participants and 32 visual snow syndrome participants (16 with migraine) using a luminance increment detection task. In the second experiment, we estimated neural contrast gain in 21 controls, 22 migraine participants and 35 visual snow syndrome participants (16 with migraine) using tasks assessing sensitivity to changes in contrast from a reference. Contrast gain and sensitivity were measured for the putative parvocellular and 'on' and 'off' magnocellular pathways, respectively. We found that luminance increment thresholds and internal noise estimates were normal in both visual snow syndrome and migraine. Contrast gain measures for putative parvocellular processing and contrast sensitivity for putative off magnocellular processing were abnormally increased in visual snow syndrome, regardless of migraine status. Therefore, our results indicate that visual snow syndrome is characterized by increased neural contrast gain but not abnormal neural noise within the targeted pathways.

Effects of Nutritional Interventions on Cardiovascular Disease Health Outcomes in Aboriginal and Torres Strait Islander Australians: A Scoping Review.

Nutrition interventions can support Aboriginal and Torres Strait Islander peoples to reduce their risk of cardiovascular disease (CVD). This review examines nutritional interventions aiming to improve CVD outcomes and appraises peer-reviewed interventions using an Aboriginal and Torres Strait Islander Quality Appraisal Tool. Five electronic databases and grey literature were searched, applying no time limit. Two reviewers completed the screening, data extraction and quality assessment independently. The study quality was assessed using the South Australian Health and Medical Research Institute and the Centre of Research Excellence in Aboriginal Chronic Disease Knowledge Translation and Exchange Aboriginal and Torres Strait Islander Quality Appraisal Tool (QAT). Twenty-one nutrition programs were included in this review. Twelve reported on anthropometric measurements, ten on biochemical and/or hematological measurements and sixteen on other outcome domains. Most programs reported improvements in measurable CVD risk factors, including reduced body mass index (BMI), waist circumference (WC), weight, blood pressure and improved lipid profiles. Most programs performed well at community engagement and capacity strengthening, but many lacked the inclusion of Indigenous research paradigms, governance and strengths-based approaches. This review highlights the need for contemporary nutrition programs aimed at improving cardiovascular health outcomes to include additional key cultural components.

Meibomian Gland Morphology Among Patients Presenting for Refractive Surgery Evaluation.

PURPOSE: To report the prevalence of meibomian gland atrophy and gland tortuosity in patients presenting for refractive surgery evaluation. METHODS: Cross-sectional study of consecutive patients presenting for refractive surgery evaluation at the Duke Eye Center from December 2018 through January 2020. All patients underwent clinical examination and meibography imaging (Lippiview II, Johnson and Johnson Vision, CA) of the lower eyelids bilaterally. Images were graded by a masked rater using a previously validated 5-point meiboscale (0-4) for gland atrophy and 3-point scale for gland tortuosity (0-2). Lipid layer thickness and partial blinks were also recorded. RESULTS: One hundred and twenty patients (49 male) aged 21 to 62 years (mean 35.2 ± 9.2 years) were reviewed. The mean meiboscale was 1.1 ± 1.0 and the mean tortuosity score was 1.0 ± 0.7. Among all patients, 72.5% (n = 87) had any evidence of meibomian gland atrophy (meiboscale >0) and 69.2% (n = 83) had any evidence of meibomian gland tortuosity (tortuosity grade ≥1). The majority of patients (n = 52) with gland atrophy had mild gland atrophy (meiboscale = 1). The mean meiboscale was 0.89 ±0.79 and 1.38 ±1.07 for those <35 years and >/= 35 years old, respectively (p = 0.01). There was a moderate positive relationship between meiboscale and tortuosity (Spearman's rho 0.3829, p <0.001). CONCLUSION: Meibomian gland atrophy is a common occurrence in patients presenting for refractive surgery evaluation. Clinicians should consider incorporating meibography as part of refractive surgery evaluation, and proactively treat meibomian gland disease given the known association between meibomian gland dysfunction, dry eye disease, and the potential for suboptimal post-operative outcomes.

NAT1 genetic variation increases asthma risk in children with secondhand smoke exposure.

OBJECTIVE: We previously reported that children exposed to secondhand smoke (SHS) that carried variants in the NAT1 gene had over two-fold higher hair cotinine levels. Our objective was to determine if NAT1 polymorphisms confer increased risk for developing asthma in children exposed to SHS. METHODS: White participants in the Cincinnati Childhood Allergy and Air Pollution Study (n = 359) were genotyped for 10 NAT1 variants. Smoke exposure was defined by hair cotinine and parental report. Asthma was objectively assessed by spirometry and methacholine challenge. Findings were replicated in the Genomic Control Cohort (n = 638). RESULTS: Significant associations between 5 NAT1 variants and asthma were observed in the CCAAPS exposed group compared to none in the unexposed group. There was a significant interaction between NAT1 rs13253389 and rs4921581 with smoke exposure (p = 0.02, p = 0.01) and hair cotinine level (p = 0.048, p = 0.042). Children wildtype for rs4921581 had increasing asthma risk with increasing hair cotinine level, whereas those carrying the NAT1 minor allele had an increased risk of asthma regardless of cotinine level. In the GCC, 13 NAT1 variants were associated with asthma in the smoke-exposed group, compared to 0 in the unexposed group, demonstrating gene-level replication. CONCLUSIONS: Variation in the NAT1 gene modifies asthma risk in children exposed to secondhand-smoke. To our knowledge, this is the first report of a gene-environment interaction between NAT1 variants, smoke exposure, cotinine levels, and pediatric asthma. NAT1 genotype may have clinical utility as a biomarker of increased asthma risk in children exposed to smoke.

Isolated choroidal melanocytosis: clinical update on 37 cases.

PURPOSE: Isolated choroidal melanocytosis is a congenital melanocytic hyperpigmentation involving the choroid that is not associated with iridic or scleral features of ocular melanocytosis. The purpose of this work was to describe the clinical features and course of a relatively large series of patients with this disorder. METHODS: A retrospective clinical study of 37 patients with isolated choroidal melanocytosis encountered in a single practice 1986-2018 was done. All lesions were 5 mm or larger in the largest basal diameter, homogeneously melanotic, and completely flat by conventional ocular ultrasonography. RESULTS: The 37 patients ranged in age from 2 weeks to 87 years (mean 31.5 years, median 18 years) at initial diagnosis of the melanotic choroidal lesion. Arc length largest basal diameter of the melanotic choroidal lesion ranged from 5.5 to 37 mm (mean 14.6 mm, median 13 mm). The lesion extended beneath the fovea in 18 eyes and to the optic disc margin in 6 eyes. Ten of the lesions straddled the ocular equator, but the center point of all of the lesions was posterior to the equator. The retina was fully attached and appeared normal over the melanotic choroidal lesion in each of these eyes. None of the melanotic choroidal lesions exhibited clumps of orange pigment or drusen on its surface. The lesion was unilateral and unifocal in 36 of the 37 patients. One patient had bilateral choroidal melanocytosis that was isolated in one eye but associated with partial iris melanocytosis in the fellow eye. Three adult patients had a choroidal melanoma localized to the patch of choroidal melanocytosis at baseline. One other adult patient had a choroidal melanoma in the fellow eye at baseline. One pediatric patient had viable unilateral non-familial retinoblastoma in the fellow eye and two adult patients had a classic choroidal nevus in the fellow eye. None of the flat patches of choroidal melanocytosis that were monitored periodically after initial diagnosis expanded appreciably during follow-up ranging from 4.9 months to 15.2 years (mean 5.0 years, median 2.3 years). CONCLUSIONS: Isolated choroidal melanocytosis is a distinct clinical entity that must be distinguished from broad-based choroidal nevus, choroidal melanocytoma, small choroidal malignant melanoma, acquired bilateral patchy-streaky choroidal melanocytic fundopathy associated with disorders such as cutaneous vitiligo and Waardenburg syndrome, acquired bilateral zonal choroidal melanocytic fundopathy, and diffuse uveal melanocytic proliferation associated with systemic cancer. This disorder appears to predispose affected eyes to development of choroidal melanoma arising from the hypermelanotic patch.

Optical Quality and Tear Film Analysis Before and After Intranasal Stimulation in Patients with Dry Eye Syndrome.

PURPOSE: To evaluate the optical quality and tear film quality in patients with dry eye syndrome (DES) before and after using an intranasal neurostimulation device to stimulate tear production. METHODS: Cross-sectional review of 33 eyes in 21 patients with DES who underwent optical quality and tear film analysis as part of their routine dry eye evaluation pre- and post-neurostimulation trial in office. Optical quality was assessed by measuring the objective scattering index (OSI) and modulation transfer function (MTF). The time to blink and mean tear film OSI were used to analyze the tear film. RESULTS: Optical quality after the use of the intranasal neurostimulator improved with an average decrease (improvement) in OSI of 0.30±0.68 (P=0.015) and an average increase (improvement) in MTF of 2.12±9.2 (P=0.15). Pre-intranasal neurostimulation OSI had a positive correlation with age (Spearman's rho 0.60, p < 0.001), while MTF had a negative correlation (Spearman's rho -0.38, p = 0.03). Pre-intranasal neurostimulation OSI had a negative correlation with MTF (Spearman's rho -0.85, p < 0.001) and a positive correlation with tear film mean OSI (Spearman's rho 0.85, p <0.001). CONCLUSION: The optical quality of patients with DES is improved with the use of intranasal neurostimulation for tear production, and there was a trend towards improved MTF though not statistically significant. Future studies are needed to follow patients longitudinally.

Management of a rhegmatogenous retinal detachment in a pregnant patient.

PURPOSE: To describe the management of a rhegmatogenous retinal detachment (RRD) in a pregnant patient. OBSERVATIONS: A 30-year-old, 26-week pregnant female presented with curtain vision loss in the left eye. Exam findings were significant in the left eye for an inferior fovea-sparing RRD. Care was coordinated and discussed with anesthesia and OB/GYN. The patient underwent surgery with monitored anesthesia care and a 41 scleral buckle, cryotherapy and C3F8 gas. The retina remained attached at 4 months post-operatively. A healthy girl was delivered via spontaneous vaginal delivery at 39 weeks. CONCLUSION: Safe and successful treatment of RRD in pregnant patients can be achieved with careful coordination between ophthalmology, anesthesia, and obstetrics. An understanding of pregnancy specific considerations is important in order to optimize patient outcomes.

Progress towards a representative network of Southern Ocean protected areas.

Global threats to ocean biodiversity have generated a worldwide movement to take actions to improve conservation and management. Several international initiatives have recommended the adoption of marine protected areas (MPAs) in national and international waters. National governments and the Commission for the Conservation of Antarctic Marine Living Resources have successfully adopted multiple MPAs in the Southern Ocean despite the challenging nature of establishing MPAs in international waters. But are these MPAs representative of Southern Ocean biodiversity? Here we answer this question for both existing and proposed Antarctic MPAs, using benthic and pelagic regionalizations as a proxy for biodiversity. Currently about 11.98% of the Southern Ocean is protected in MPAs, with 4.61% being encompassed by no-take areas. While this is a relatively large proportion of protection when compared to other international waters, current Antarctic MPAs are not representative of the full range of benthic and pelagic ecoregions. Implementing additional protected areas, including those currently under negotiation, would encompass almost 22% of the Southern Ocean. It would also substantially improve representation with 17 benthic and pelagic ecoregions (out of 23 and 19, respectively) achieving at least 10% representation.

Cataract surgery in patients with left ventricular assist devices.

PURPOSE: To determine the safety and efficacy of cataract surgery in patients with left ventricular assist devices (LVADs). SETTING: Duke Eye Center, Durham, North Carolina, USA. DESIGN: Retrospective case series. METHODS: Electronic medical records were used to collect patient demographics, preoperative planning, intraoperative details, and postoperative outcomes of patients with LVADs who underwent cataract surgery between March 2012 and August 2019. RESULTS: A total of 53 cataract surgeries were identified involving 31 patients. Most patients were men (n = 27) and white (n = 25) with a mean age of 69.5 years. Preoperative biometry was unchanged from standard protocol. Femtosecond laser, intraoperative aberrometry, and/or a premium IOL was used in 25 cases (47.2%) . Patients were on warfarin, warfarin plus aspirin, and warfarin plus clopidogrel in 51.6% (n = 16), 45.2% (n = 14), and 3.2% (n = 1) of cases, respectively. Patients underwent topical anesthesia with monitored anesthesia care from an experienced LVAD team as planned with no episodes of hemodynamic instability, respiratory compromise, or intraoperative adverse events related to the LVAD. All patients were discharged the same day as surgery. There were no hospitalizations or deaths within 30 days that were attributed to the cataract procedure. At 1 month postoperatively, 61.1% of eyes were ±0.5 diopter of their predicted spherical equivalent (n = 11/18), with a high proportion of patients returning to local providers for postoperative care. CONCLUSIONS: Cataract surgery was safe and feasible in patients with LVADs when performed with additional perioperative considerations and in conjunction of an experienced LVAD team. The presence of LVAD itself was not found to be a contraindication for cataract surgery.

Consolidation of Imaging Modalities Utilizing Digitally Assisted Visualization Systems: The Development of a Surgical Information Handling Cockpit.

The management of vitreoretinal cases is ever-evolving, paralleled by rapid advancements in operative imaging modalities. In this article, we describe an advanced application of digitally assisted vitreoretinal surgery (DAVS) that involves the consolidation of pre-existing ancillary imaging technology into a single same-screen viewing platform. Forty-four eyes of 44 patients were operated using same screen simultaneous viewing of the primary three-dimensional high definition (3DHD) surgical field and simultaneous auxiliary video feed viewing of all currently approved ocular endoscopy (n=12), intraoperative optical coherence tomography (iOCT) units (n=24), or computer feeds from the EHR/image management software (n=8). All surgeries were successful with excellent functional and anatomic outcomes. DAVS facilitated same screen viewing of multiple video/information feeds was notable for improved ergonomics, surgical efficiency, and precision when compared to viewing the surgical field and auxiliary video feeds separately. We describe a new concept for the vitreoretinal operating room - a DAVS-based surgical information handling cockpit - integrating FDA approved ocular endoscopy (n=1), microscope-integrated iOCT units (n=3), and one EHR/Image management solution with the primary surgical field 3DHD feed. We suggest same screen viewing of multiple video and other clinical information feeds is a promising modality that may be considered in the management of patients with surgical vitreoretinal disease and should be purposefully incorporated into future iterations of DAVS technology platforms.

Dexamethasone 0.4mg Sustained-Release Intracanalicular Insert in the Management of Ocular Inflammation and Pain Following Ophthalmic Surgery: Design, Development and Place in Therapy.

Inflammation and pain are two prevalent findings after ocular surgery. Corticosteroids are widely administrated as a core treatment to control post-surgical inflammation and pain. Improper patient adherence to post-operative eye drop regimens, limited bioavailability of topical eye drops, and the negative impact of preservatives used in many of these eye drops, has made a strong case for novel therapies in the treatment of post-operative pain and inflammation. This review of the literature will focus on the role of intracanalicular sustained-release dexamethasone (Dextenza, Ocular Therapeutix, Bedford, MA, USA) for the management of ocular inflammation and pain.

Impacts of older age on the temporal properties of collinear facilitation.

Collinear facilitation is a visual phenomenon by which the contrast detection threshold of a central target is reduced (facilitation) when placed equidistant between two high-contrast flankers. The neural mechanisms underpinning this phenomenon originate from feed-forward lateral facilitation between cell layers in V1 (slower) and feedback facilitation from extrastriate visual areas to V1 (faster). The strength of these contributions has been explored in younger adults by presenting the central target and flankers at varying timing offsets. Here, we investigated the effects of older age on collinear facilitation with flankers presented in sync, before, and after target onset, to allow the inference of any characteristic effect of older age on feed-forward and feedback facilitatory mechanisms. Seventeen older and 19 younger observers participated. Our data confirms previous findings of an age-related reduction in facilitation when flankers and target occur at synchrony, but no age difference was found at other timings. Marked interindividual variability in facilitation for the different flanker onset timings was present, which was repeatable within individuals. Further research is required to ascertain the mechanistic underpinnings for different facilitation profiles between individuals. Longitudinal study across an individual's life span is needed to determine whether an individual's facilitation profile changes with age.