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Background: Bloodstream infections (BSIs) are a leading cause of hospitalizations and mortality among patients receiving hemodialysis (HD) therapy, especially those with a central venous catheter (CVC) for dialysis access. The use of chlorhexidine impregnated catheter caps (ClearGuard) has been associated with a decrease in the rate of HD catheter-related BSIs (CA-BSIs) in adults; similar data have not been published for children. Methods: We compared CA-BSI data from participating centers within the Standardizing Care to Improve Outcomes in Pediatric Endstage Kidney Disease (SCOPE) collaborative based on the center's use of ClearGuard caps for patients with HD catheter access. Centers were characterized as ClearGuard (CG) or non-ClearGuard (NCG) centers, with CA-BSI data pre- and post-CG implementation reviewed. All positive blood cultures in participating centers were reported to the SCOPE collaborative and adjudicated by an infectious disease physician. Results: Data were available from 1786 SCOPE enrollment forms completed January 2016–January 2022. January 2020 served as the implementation date for analyzing CG versus NCG center data, with this being the time when the last CG center underwent implementation. Post January 2020, there was a greater decrease in the rate of HD CA-BSI in CG centers versus NCG centers, with a decrease from 1.18 to 0.23 and 0.41 episodes per 100 patient months for the CG and NCG centers, respectively (p = 0.002). Conclusions: Routine use of ClearGuard caps in pediatric dialysis centers was associated with a reduction of HD CA-BSI rates in pediatric HD patients. [ABSTRACT FROM AUTHOR]

A correction is presented to the article "Use of ClearGuard HD caps in pediatric hemodialysis patients" published in a previous issue of the periodical.

Antarctic sea ice is known to provide unique ecosystem habitat at the ice–ocean interface. Mapping sea ice characteristics—such as thickness and roughness—at high resolution from beneath the ice is difficult due to access. A Geoswath Plus phase-measuring bathymetric sonar mounted on an autonomous underwater vehicle (AUV) was employed in this study to collect data underneath the sea ice at Cape Evans in Antarctica in November 2014. This study demonstrates how acoustic data can be collected and processed to resolutions of 1 m for acoustic bathymetry and 5 cm for acoustic backscatter in this challenging environment. Different ice textures such as platelet ice, smooth ice, and sea ice morphologies, ranging in size from 1 to 50 m were characterized. The acoustic techniques developed in this work could provide a key to understanding the distribution of sea ice communities, as they are nondisruptive to the fragile ice environments and provide geolocated data over large spatial extents. These results improve our understanding of sea ice properties and the complex, highly variable ecosystem that exists at this boundary. [ABSTRACT FROM AUTHOR]

Visual sensory substitution devices provide a non-surgical and flexible approach to vision rehabilitation in the blind. These devices convert images taken by a camera into cross-modal sensory signals that are presented as a surrogate for direct visual input. While previous work has demonstrated that the visual cortex of blind subjects is recruited during sensory substitution, the cognitive basis of this activation remains incompletely understood. To test the hypothesis that top-down input provides a significant contribution to this activation, we performed functional MRI scanning in 11 blind (7 acquired and 4 congenital) and 11 sighted subjects under two conditions: passive listening of image-encoded soundscapes before sensory substitution training and active interpretation of the same auditory sensory substitution signals after a 10-minute training session. We found that the modulation of visual cortex activity due to active interpretation was significantly stronger in the blind over sighted subjects. In addition, congenitally blind subjects showed stronger task-induced modulation in the visual cortex than acquired blind subjects. In a parallel experiment, we scanned 18 blind (11 acquired and 7 congenital) and 18 sighted subjects at rest to investigate alterations in functional connectivity due to visual deprivation. The results demonstrated that visual cortex connectivity of the blind shifted away from sensory networks and toward known areas of top-down input. Taken together, our data support the model of the brain, including the visual system, as a highly flexible task-based and not sensory-based machine. [ABSTRACT FROM AUTHOR]

It is commonly accepted that the blind can partially compensate for their loss of vision by developing enhanced abilities with their remaining senses. This visual compensation may be related to the fact that blind people rely on their other senses in everyday life. Many studies have indeed shown that experience plays an important role in visual compensation. Numerous neuroimaging studies have shown that the visual cortices of the blind are recruited by other functional brain areas and can become responsive to tactile or auditory input instead. These cross-modal plastic changes are more pronounced in the early blind compared to late blind individuals. The functional consequences of cross-modal plasticity on visual compensation in the blind are debated, as are the influences of various etiologies of vision loss (i.e., blindness acquired early or late in life). Distinguishing between the influences of experience and visual deprivation on compensation is especially relevant for rehabilitation of the blind with sensory substitution devices. The BrainPort artificial vision device and The vOICe are assistive devices for the blind that redirect visual information to another intact sensory system. Establishing how experience and different etiologies of vision loss affect the performance of these devices may help to improve existing rehabilitation strategies, formulate effective selection criteria and develop prognostic measures. In this review we will discuss studies that investigated the influence of training and visual deprivation on the performance of various sensory substitution approaches. [ABSTRACT FROM AUTHOR]

We have observed dramatic effects of tactile tongue stimulation on nystagmus eye movements in patients with acquired blindness, and we report these results. Six adult subjects (3 subjects with light perception or worse vision and 3 normal subjects) were included in this study. Causes of blindness included traumatic explosion, anterior ischemic optic neuropathy, and central retinal artery occlusion. Duration of blindness was 15, 3 and 1.5 years, respectively. A video eye tracking system (Eyelink 1000) was used to record eye movements. The eye movement recording (EMR) was repeated four times in a span of 20 min. Two of the EMRs were performed without tongue stimulation and two with tongue stimulation in randomized order. A tongue stimulus was applied to the surface of the tongue using a Brainport device that produces an electrical tactile stimulus. The nystagmus waveform characteristics and frequency were analyzed. We found that all blind subjects showed continuous jerk nystagmus with slow and quick phases, mainly in horizontal plane in their primary eye positions. The recorded nystagmus waveforms were jerk with linear velocity slow phases. When the tongue stimulus was applied, the frequency of nystagmus was significantly reduced by 47, 40, and 11%, and relative amplitude was reduced by 43, 45, and 6% for three blind subjects, respectively. In conclusion, we think our results that tongue stimulation influences nystagmus eye movements support a link between non-visual sensory input and ocular motor activity. [ABSTRACT FROM AUTHOR]

Objective: To describe outcomes using impression based-scleral devices for the management of anterior segment disease.Methods: Retrospective chart review identified all patients who were fitted with impression-based scleral devices between January 1, 2013 and June 30, 2019 at three specialty contact lens practices. Patient demographic data, indication for device use, visual and physiological outcomes, as well as details of the fitting process and survival of device use were determined.Results: Forty-four patients (70 eyes) were included in the study. Primary indications for device use included corneal irregularity (28 patients, 44 eyes) and ocular surface disease (16 patients, 26 eyes). Fifty-four percent of patients had more than one ocular surface condition, and 39 % of patients had undergone at least one anterior segment surgical procedure. Twenty-nine patients had unsuccessfully attempted to wear standard scleral lenses prior to being fit with impression-based devices. Visual acuity improved significantly with impression-based devices compared to habitual correction (p < 0.001). Completion of the fitting process (including visit to acquire the impression and post-fitting assessments) required an average of 4 [1.5] visits.Ideal haptic alignment was achieved with 74 % and complete limbal clearance was achieved in 83 % of fits. Device use was discontinued due to complications in two eyes.Conclusion: Patients with complex eye disease who are unable to successfully wear standard scleral lenses successfully may achieve visual and therapeutic success with impression-based devices. [ABSTRACT FROM AUTHOR]

Introduction: Midday fogging is a complication of scleral lens (SL) wear that interrupts clear vision during the course of wear. SLs can be made with a variety of gas permeable materials, sizes and surface treatments, and various solutions are available for storing the lenses and for filling them before application on the eye. Many of these factors have been implicated as possible contributors to midday fogging. This study explored the lens and solution properties in habitual SL wearers with and without midday fogging. Methods: In this prospective study, 48 habitual SL wearers were evaluated and asked to report whether they experienced midday fogging and if they removed their lenses during the day. They completed the Ocular Surface Disease Index (OSDI), which is a validated tool for dry eye assessment. Lens parameters (material, coatings and diameter) and lens storage and filling solutions were documented. Backward elimination of regression terms evaluated the lens and solution properties in those with and without fogging. OSDI scores were compared using the Mann–Whitney analysis. Results: Collectively, the lens properties and solutions accounted for 27.7% of the variance related to midday fogging. None of the factors alone had a significant impact upon midday fogging. The median (interquartile range) OSDI score for those with fogging [37 (35)] was significantly different from those without fogging [10 (15)], with the scores corresponding to severe dry eye and normal eyes, respectively. Conclusion: SL wearers with midday fogging exhibited similar symptoms to patients with severe dry eye. Lens and solution characteristics may play a small role in patients with midday fogging, although changing just a single factor is not likely to impact its presence. [ABSTRACT FROM AUTHOR]

Purpose: To describe patient-specific outcomes of scleral lens wear utilizing a variety of lens designs across multiple practice settings as reported in an international practitioner survey.Methods: An electronic survey was administered to eye care providers who prescribe scleral lenses in which they were asked to describe their most recently examined established scleral lens patient. Data was collected on patient characteristics, lens designs, wearing schedules, care products, and visual and physiological outcomes of lens wear. Descriptive analysis of data was performed.Results: A total of 292 responses were received. Participants represented 26 countries. The most commonly reported indication for scleral lens wear was corneal irregularity (87%) followed by ocular surface disease (8%), refractive error (4%) and 1% with multiple indications. Visual acuity improved from 0.4 ± 0.4 (mean ± SD) to 0.1 ± 0.2 in eyes with corneal irregularity (p < 0.001), from 0.3 ± 0.3 to 0.1 ± 0.3 in eyes with ocular surface disease (p < 0.001), and from 0.1 ± 0.1 to 0.0± [0.1] in eye with refractive error (p = 0.01). Prior to scleral lens wear, corneal staining was present in 55% of patients; staining was present in only 35% of patients following scleral lens wear. The number of topical ophthalmic drops needed decreased from 1.7 ± 0.9 to 0.8 ± 0.8 in patients with corneal irregularity (p < 0.001) and from 3.5 ± 1.7 to 1.1 ± 1.0 in patients with ocular surface disease (p < 0.001). The number of drops used by patients with refractive error remained stable, with these patients using an average of 2.0 ± 1.0 drops prior to scleral lens wear and 1.7 ± 1.5 drops following scleral lens wear.Conclusions: Patients with corneal irregularity experienced the greatest improvement in visual acuity, but patients with ocular surface disease and refractive error also achieved better visual acuity with scleral lenses. Ocular surface condition improved in patients with both corneal irregularity and ocular surface disease; patients with ocular surface disease experienced the most dramatic improvement. Patients who wore scleral lenses to correct uncomplicated refractive error did not experience an improvement in signs or symptoms of ocular surface disease. [ABSTRACT FROM AUTHOR]

• This study confirmed corneal irregularity as the most common indication for scleral lens wear. • The fitting process for scleral lenses is comparable to that of other specialty lenses. • The mean diameter of scleral lenses is approximately 16 mm. • A majority of patients in this sample wore lenses with spherical landing zones. • Care regimen commonly featured daily cleaner, hydrogen peroxide disinfection, and single-use vials of nonpreserved saline. To describe international scleral lens prescription and management practices across multiple practice types. For this cross-sectional study, scleral lens practitioners were asked to complete an electronic survey that requested information about a single scleral lens patient. Data collected included practitioner demographics (practice type, country, years of experience) and patient indications for scleral lens wear, fitting process, lens design, and care products. Data were collected for 259 patients (419 eyes). Most participants (60%) practiced in the US, 75% worked primarily in community practice, and 58% claimed more than 5 years' experience fitting scleral lenses. Indications for scleral lens wear were corneal irregularity (87%), ocular surface disease (9%), and uncomplicated refractive error (4%). During the fitting process, the mean (SD) number of lenses ordered was 2.4 (1.6) (range, 1–16 lenses) during 3.8 (2.4) visits (range, 1–18 visits). Of patients, 62% used a daily surfactant cleaner, 47% used hydrogen peroxide disinfection, and 67% used single-use vials of nonpreserved saline. Mean lens diameter was 16.2 (1.1) mm (range, 11.8–23.0 mm). The landing zones were spherical (64%), toric (26%), quadrant-specific (7%), and custom (3%) designs. Optical power was spherical in 70%, toric in 27%, and higher-order aberration correcting in 3% of lenses. Only 5 lenses had multifocal optics. General consensus regarding prescribing patterns (lens design, wearing schedules, care products) between US vs non-US, community vs academic, and new vs established providers is reported in this study. Relatively low percentages of patients wearing lenses with advanced landing zones or optical designs suggest that these new options have not been widely adopted. [ABSTRACT FROM AUTHOR]

Abstract: Ciguatera fish poisoning (CFP) is a circumtropical disease caused by ingestion of a variety of reef fish that bioaccumulate algal toxins. Distribution and abundance of the organisms that produce these toxins, chiefly dinoflagellates of the genus Gambierdiscus, are reported to correlate positively with water temperature. Consequently, there is growing concern that increasing temperatures associated with climate change could increase the incidence of CFP. This concern prompted experiments on the growth rates of six Gambierdiscus species at temperatures between 18°C and 33°C and the examination of sea surface temperatures in the Caribbean and West Indies for areas that could sustain rapid Gambierdiscus growth rates year-round. The thermal optimum for five of six Gambierdiscus species tested was ≥29°C. Long-term SST data from the southern Gulf of Mexico indicate the number of days with sea surface temperatures ≥29°C has nearly doubled (44 to 86) in the last three decades. To determine how the sea surface temperatures and Gambierdiscus growth data correlate with CFP incidences in the Caribbean, a literature review and a uniform, region-wide survey (1996–2006) of CFP cases were conducted. The highest CFP incidence rates were in the eastern Caribbean where water temperatures are warmest and least variable. [ABSTRACT FROM AUTHOR]

Purpose: To estimate the prevalence of patient-reported midday fogging and to identify risk factors for midday fogging.Method: A multicenter, cross-sectional study was conducted with an electronic survey that was distributed to scleral lens practitioners. The survey asked them to describe their most recently examined established scleral lens patient. Respondents provided data about patient-reported midday fogging, patient demographic characteristics, indication for lens wear, lens-wearing schedule, lens design, and care products.Results: Of the 248 survey respondents who indicated whether their patients had midday fogging, 64 (25.8 %) had patients who self-reported such issues. Midday fogging was not associated with demographic characteristics (age, sex, race/ethnicity), indications for scleral lens wear, mean lens diameter (P = .30), haptic design (P = .29), use of a daily cleaner (P = .12), disinfection/storage solution used (P = .71), or filling solution (P = .65). Patients who reported midday fogging more commonly reported redness or irritation associated with scleral lens wear compared with those who did not experience midday fogging (P = .03).Conclusions: Prevalence of midday fogging in this study was similar to previously reported rates. No specific lens design or care product was associated with patient-reported midday fogging. If inflammatory mediators are elevated in the postlens fluid reservoir of patients with midday fogging, as previously described, the redness or irritation associated with scleral lens wear suggests that ocular surface inflammation may be contributing to this phenomenon. [ABSTRACT FROM AUTHOR]

Purpose: To describe prescriber reported scleral lens fitting and assessment strategies.Methods: The SCOPE (Scleral Lenses in Current Ophthalmic Practice Evaluation) study group designed and administered an IRB approved, electronic survey (REDCap) regarding current scleral lens fitting and assessment methods. The survey was distributed to attendees of the 2017 Global Specialty Lens Symposium.Results: 95 practitioners responded to the survey. Over half of the respondents, 58% (55/95) reported fitting scleral lenses for less than five years (new prescribers), and 42% (40/95) reported fitting scleral lenses for more than five years (experienced prescribers). There was a statistically significant difference between their initial use of technology (χ2 = 21.117, p < 0.0005) in selection of a diagnostic lens. New prescribers consider base curve first (60%, 33/55), while experienced prescribers considered sagittal depth first (63%, 25/40) in their initial scleral lens selection. All of the experienced lens prescribers (100%, 39/39) reported estimating central clearance by comparing thickness of the post-lens tear reservoir to scleral lens thickness using a slit lamp beam at least some of the time, and 62% of new scleral lens prescribers (34/55; χ2 = 19.175, p < 0.0005) reported doing so. All (100%, 40/40) experienced prescribers schedule scleral lens follow-ups at a specific time and assess conjunctival compression (100%, 40/40), conjunctival staining (100%, 39/39), and corneal staining (100%,40/40) after lens removal.Conclusions: Practitioners with varying backgrounds and experience have added sclerals to their lens inventories. However, definite guidelines for fitting have not been developed. The results of a survey are provided; demonstrating that among practitioners with greater than 5 years of scleral lens experience, a consensus has emerged for best practices. Strategies for lens evaluation, which may inform future efforts at generating scleral fitting standards are described. [ABSTRACT FROM AUTHOR]

Vision impairments such as age-related macular degeneration (AMD) and glaucoma are among the top risk factors for geriatric falls and falls-related injuries. AMD and glaucoma lead to loss of the central and peripheral visual fields, respectively. This study utilized a custom contact lens model to occlude the peripheral or central visual fields in healthy adults, offering a novel within-subject approach to improve our understanding of the etiology of balance impairments that may lead to an increased fall risk in patients with visual field loss. Two dynamic posturography tests, including an adapted version of the Sensory Organization Test and a virtual reality environment with the visual scene moving sinusoidally, were used to evaluate standing balance. Balance stability was quantified by displacement and time-normalized path length of the center of pressure. Nine young and eleven older healthy adults wore visual field occluding contact lenses during posturography assessments to compare the effects of acute central and peripheral visual field occlusion. The results found that visual field occlusion had greater impact on older adults than young adults, specifically when proprioceptive cues are unreliable. Furthermore, the results suggest that both central and peripheral visions are important in postural control; however, peripheral vision may be more sensitive to movement in the environment. [ABSTRACT FROM AUTHOR]

Introduction: This study was conducted to evaluate the functional performance of the BrainPort V100 device, an FDA-cleared sensory-substitution system, in persons who are profoundly blind (that is, have some or no light perception). Methods: This was a prospective, single-arm, multicenter clinical investigation. Participants received 10 hours of device training and were required to use the device in their everyday environments for 1 year. Functional performance measures of object identification, orientation and mobility (O&M), and word identification were assessed at baseline, in post-device training, and at the 3-, 6-, 9-, and 12-month time points. Results: Fifty-seven participants completed the study and used the device for 1 year. No device-related serious adverse events were reported, demonstrating that the risks associated with the BrainPort are minimal. Participants performed object recognition (91.2% success rate) and O&M (57.9% success rate) tasks beyond chance level. Discussion: This study demonstrates that the BrainPort can be used safely and independently by persons who are blind. Participants with profound blindness can accomplish a set of tasks more successfully by using the BrainPort than without the device. Following initial training, performance on these tasks was maintained or improved over the course of 1 year. Implications for practitioners: The BrainPort is a noninvasive and nonsurgical device that heightens functional independence for persons who are blind. The device presents users with more information about their environment than conventional assistive devices, and can enhance independence in performing activities of daily living. [ABSTRACT FROM AUTHOR]

Abstract: Dinoflagellates in the genus Gambierdiscus produce toxins that bioaccumulate in tropical and sub-tropical fishes causing ciguatera fish poisoning (CFP). Little is known about the diversity and distribution of Gambierdiscus species, the degree to which individual species vary in toxicity, and the role each plays in causing CFP. This paper presents the first global distribution of Gambierdiscus species. Phylogenetic analyses of the existing isolates indicate that five species are endemic to the Atlantic (including the Caribbean/West Indies and Gulf of Mexico), five are endemic to the tropical Pacific, and that two species, Gambierdiscus carpenteri and Gambierdiscus caribaeus are globally distributed. The differences in Gambierdiscus species composition in the Atlantic and Pacific correlated with structural differences in the ciguatoxins reported from Atlantic and Pacific fish. This correlation supports the hypothesis that Gambierdiscus species in each region produce different toxin suites. A literature survey indicated a >100-fold variation in toxicity among species compared with a 2 to 9-fold within species variation due to changing growth conditions. These observations suggest that CFP events are driven more by inherent differences in species toxicity than by environmental modulation. How variations in species toxicity may affect the development of an early warning system for CFP is discussed. [ABSTRACT FROM AUTHOR]

Objectives: To describe current components of scleral lens curricula at U.S. based optometry colleges and universities.Methods: Contact lens educators were surveyed between June 2019 and August 2019 regarding their optometric scleral lens curriculum. Respondents were asked to describe their experience and involvement in optometric scleral lens education as well as to describe components of scleral lens curricula. Educators were also asked to identify sources of information upon which they rely on in order to stay informed about new developments and best practices in scleral lens prescription and management.Results: Most programs begin scleral lens education during the 3rd year of optometric education (71.2 %; n = 52). Students complete an estimated 18.0 ± 18.1 (range 2-100) scleral lens evaluations during training (n = 36). Ideal fitting characteristics taught include central corneal clearance of 206.3 ± 44 microns (range 150-350, n = 40), limbal clearance of 62.1 ± 23.6 microns (range 20-100, n = 36) with one clock hour or less of conjunctival vascular compression (n = 41). Educators ranked in-person continuing education (61 %, 22/36) followed by contact lens laboratory consults (22 %, 8/36) as the two most important sources of information on best practices in scleral lens prescription and management.Conclusions: Educators are uniquely positioned to guide the next generation of eyecare providers by incorporating and disseminating new research findings into their scleral lens curricula. [ABSTRACT FROM AUTHOR]

The biogeography of the deep-sea benthic fauna is uncertain due to the vast size and incomplete exploration of these environments. While shallow water assemblages are differentiated into tropical, temperate and polar faunas, it is unknown whether these units extend to lower depths. Here we use model-based and multivariate statistics to analyse megafaunal benthic samples along a 2300 km transect off the eastern Australian continental margin. We show that a temperate-tropical transition between 33-30°S occurs at both lower bathyal (~2500 m) and abyssal (~4000 m) depths. This transition occurs despite almost uniform temperature, salinity and dissolved oxygen concentrations occurring across latitudes at these depths. Conversely, the patterns are consistent with the flux of organic matter to the seafloor, which varies from being relatively high in the productive temperate off SE Australia to low levels in more-oligotrophic tropical waters. Biodiversity is not uniform across the deep-sea and regional-scale heterogeneity needs to be incorporated into marine park designs. • There is a significant temperate-tropical transition in benthic assemblages at bathyal-abyssal depths off eastern Australia • The transition is congruent with variation in net primary productivity but not gradients of temperature, salinity or oxygen • The deep-sea habitats are not uniform and assemblage composition differs at regional scales [ABSTRACT FROM AUTHOR]