Mapping standard ophthalmic outcome sets to metrics currently reported in eight eye hospitals

BACKGROUND

To determine alignment of proposed international standard outcomes sets for ophthalmic conditions to metrics currently reported by eye hospitals.

METHODS

Mixed methods comparative benchmark study, including eight eye hospitals in Australia, India, Singapore, Sweden, U.K., and U.S. All are major international tertiary care and training centers in ophthalmology. Main outcome measure is consistency of ophthalmic outcomes measures reported.

RESULTS

International agreed standard outcomes (ICHOM) sets are available for cataract surgery (10 metrics) and macular degeneration (7 metrics). The eight hospitals reported 22 different metrics for cataract surgery and 2 for macular degeneration, which showed only limited overlap with the proposed ICHOM metrics. None of the hospitals reported patient reported visual functioning or vision-related quality of life outcomes measures (PROMs). Three hospitals (38%) reported rates for uncomplicated cataract surgeries only. There was marked variation in how and at what point postoperatively visual outcomes following cataract, cornea, glaucoma, strabismus and oculoplastics procedures were reported. Seven (87.5%) measured post-operative infections and four (50%) measured 30 day unplanned reoperation rates.

CONCLUSIONS

Outcomes reporting for ophthalmic conditions currently widely varies across hospitals internationally and does not include patient-reported outcomes. Reaching consensus on measures and consistency in data collection will allow meaningful comparisons and provide an evidence base enabling improved sharing of "best practices" to improve eye care globally. Implementation of international standards is still a major challenge and practice-based knowledge on measures should be one of the inputs of the international standardization process.

The Effects of Methylphenidate on the Neural Signatures of Sustained Attention

BACKGROUND

Although it is well established that methylphenidate (MPH) enhances sustained attention, the neural mechanisms underpinning this improvement remain unclear. We examined how MPH influenced known electrophysiological precursors of lapsing attention over different time scales.

METHODS

We measured the impact of MPH, compared with placebo, on behavioral and electrocortical markers while healthy adults (n = 40) performed a continuous monitoring paradigm designed to elicit attentional lapses.

RESULTS

MPH led to increased rates of target detection, and electrophysiological analyses were conducted to identify the mechanisms underlying these improvements. Lapses of attention were reliably preceded by progressive increases in alpha activity that emerged over periods of several seconds. MPH led to an overall suppression of alpha activity across the entire task but also diminished the frequency of these maladaptive pretarget increases through a reduction of alpha variability. A drug-related linear increase in the amplitude of the frontal P3 event-related component was also observed in the pretarget timeframe (3 or 4 seconds). Furthermore, during immediate target processing, there was a significant increase in the parietal P3 amplitude with MPH, indicative of enhanced perceptual evidence accumulation underpinning target detection. MPH-related enhancements occurred without significant changes to early visual processing (visual P1 and 25-Hz steady-state visual evoked potential).

CONCLUSIONS

MPH serves to reduce maladaptive electrophysiological precursors of lapsing attention by acting selectively on top-down endogenous mechanisms that support sustained attention and target detection with no significant effect on bottom-up sensory excitability. These findings offer candidate markers to monitor the therapeutic efficacy of psychostimulants or to predict therapeutic responses.

The spatiotemporal characteristics of the C1 component and its modulation by attention

Slotnick (this issue) provided a selective review of studies on the attentional modulation of the C1 component of the visual evoked potential, and offers a number of guidelines to maximize the likelihood of observing such modulation in terms of electrode choice, stimulus placement, and types of attentional cue and target stimulus. However, the broader literature pertaining to attentional modulation of the C1 does not support many of these guidelines, and the question of why exactly C1 modulations are so rare remains very much open. Here, we provide clarifications that are critical to an accurate appraisal of the current state of this literature.

A resource for assessing information processing in the developing brain using EEG and eye tracking

We present a dataset combining electrophysiology and eye tracking intended as a resource for the investigation of information processing in the developing brain. The dataset includes high-density task-based and task-free EEG, eye tracking, and cognitive and behavioral data collected from 126 individuals (ages: 6–44). The task battery spans both the simple/complex and passive/active dimensions to cover a range of approaches prevalent in modern cognitive neuroscience. The active task paradigms facilitate principled deconstruction of core components of task performance in the developing brain, whereas the passive paradigms permit the examination of intrinsic functional network activity during varying amounts of external stimulation. Alongside these neurophysiological data, we include an abbreviated cognitive test battery and questionnaire-based measures of psychiatric functioning. We hope that this dataset will lead to the development of novel assays of neural processes fundamental to information processing, which can be used to index healthy brain development as well as detect pathologic processes.

The prevalence of visual symptoms in poppers users: a global survey

Introduction and aims

The use of ‘poppers’ (volatile alkyl nitrites) has been associated with the development of visual symptoms secondary to the development of maculopathy. There are currently no data regarding the prevalence of this condition among poppers users. The aim of this study was to quantify the presence of visual symptoms among poppers users from a global cohort.

Design and methods

The Global Drug Survey (GDS) conducts annual anonymous online surveys of drug and alcohol use. Within the 2012 GDS, questions were inserted regarding the presence of visual symptoms in poppers users.

Results

The GDS received a total of 21 575 valid responses, with a total of 17 479 from the UK, Australia, USA and Eurozone. Within these areas, 5152 (29.5%) had used poppers within their lifetime and 1322 (7.6%) within the previous year. Of the ‘last year’ users, when asked the question: ‘Do you think poppers use has affected your eyesight?’, 29 (2.2%) people responded ‘yes’, 130 (10.0%) responded ‘maybe’ and 1146 (87.8%) responded ‘no (17 people did not answer). Both multiple choice and free-text responses regarding the nature of visual symptoms correlated with the central visual disturbance that would be expected from maculopathy. There was significant increased symptom prevalence with age (likelihood ratio (χ²)=19.0; p<0.001).

Discussion and conclusions

This study demonstrates that a small, yet significant from a public health perspective, proportion of poppers users have visual symptoms. Clinical correlation is required to determine whether these reported symptoms are due to poppers associated maculopathy, or an alternative cause.

Response time variability under slow and fast-incentive conditions in children with ASD, ADHD and ASD+ADHD

BACKGROUND

Attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) show significant behavioural and genetic overlap. Both ADHD and ASD are characterised by poor performance on a range of cognitive tasks. In particular, increased response time variability (RTV) is a promising indicator of risk for both ADHD and ASD. However, it is not clear whether different indices of RTV and changes to RTV according to task conditions are able to discriminate between the two disorders.

METHODS

Children with ASD (n = 19), ADHD (n = 18), ASD + ADHD (n = 29) and typically developing controls (TDC; n = 26) performed a four-choice RT task with slow-baseline and fast-incentive conditions. Performance was characterised by mean RT (MRT), standard deviation of RT (SD-RT), coefficient of variation (CV) and ex-Gaussian distribution measures of Mu, Sigma and Tau.

RESULTS

In the slow-baseline condition, categorical diagnoses and trait measures converged to indicate that children with ADHD-only and ASD + ADHD demonstrated increased MRT, SD-RT, CV and Tau compared to TDC and ASD-only. Importantly, greater improvement in MRT, SD-RT and Tau was demonstrated in ADHD and ASD + ADHD from slow-baseline to fast-incentive conditions compared to TDC and ASD-only.

CONCLUSIONS

Slower and more variable RTs are markers of ADHD compared to ASD and typically developing controls during slow and less rewarding conditions. Energetic factors and rewards improve task performance to a greater extent in children with ADHD compared to children with ASD. These findings suggest that RTV can be distinguished in ASD, ADHD and ASD + ADHD based on the indices of variability used and the conditions in which they are elicited. Further work identifying neural processes underlying increased RTV is warranted, in order to elucidate disorder-specific and disorder-convergent aetiological pathways.

Tracking neural correlates of successful learning over repeated sequence observations

The neural correlates of memory formation in humans have long been investigated by exposing subjects to diverse material and comparing responses to items later remembered to those forgotten. Tasks requiring memorization of sensory sequences afford unique possibilities for linking neural memorization processes to behavior, because, rather than comparing across different items of varying content, each individual item can be examined across the successive learning states of being initially unknown, newly learned, and eventually, fully known. Sequence learning paradigms have not yet been exploited in this way, however. Here, we analyze the event-related potentials of subjects attempting to memorize sequences of visual locations over several blocks of repeated observation, with respect to pre- and post-block recall tests. Over centro-parietal regions, we observed a rapid P300 component superimposed on a broader positivity, which exhibited distinct modulations across learning states that were replicated in two separate experiments. Consistent with its well-known encoding of surprise, the P300 deflection monotonically decreased over blocks as locations became better learned and hence more expected. In contrast, the broader positivity was especially elevated at the point when a given item was newly learned, i.e., started being successfully recalled. These results implicate the Broad Positivity in endogenously-driven, intentional memory formation, whereas the P300, in processing the current stimulus to the degree that it was previously uncertain, indexes the cumulative knowledge thereby gained. The decreasing surprise/P300 effect significantly predicted learning success both across blocks and across subjects. This presents a new, neural-based means to evaluate learning capabilities independent of verbal reports, which could have considerable value in distinguishing genuine learning disabilities from difficulties to communicate the outcomes of learning, or perceptual impairments, in a range of clinical brain disorders.

Wrong intraocular lens events-what lessons have we learned? A review of incidents reported to the National Reporting and Learning System: 2010-2014 versus 2003-2010

PurposeTo identify the causal factors in wrong intraocular lens (IOL) events from a national data set and to compare with similar historical data (2003-2010) prior to mandatory checklist use, for the purpose of developing strategies to prevent never events.MethodsData from wrong IOL patient safety incidents (PSIs) submitted to the National Reporting and Learning System (2010-2014) were reviewed by thematic analysis and compared with the data previously collected by the group using the same methodology.ResultsOne hundred and seventy eight wrong IOL PSIs were identified. The contributory factors included: transcription errors (n=26); wrong patient biometry (n=21); wrong IOL selection (n=16); changes in planned procedure (n=16); incorrect IOL brought into theatre (n=11); left/right eye selection errors (n=9); communication errors (n=9); and positive/negative IOL power errors (n=9). In 44 PSIs, no causal factor was reported, limiting the learning value of such reports. Compared with the data from previous years, biometry errors were much reduced but IOL transcription and documentation errors were greater, particularly if further checks did not refer to the original source documentation. IOL exchange surgery was reported in 45 cases.ConclusionsThe selection and implantation of the correct IOL is a complex process which is not adequately addressed by existing checking procedures. Despite the introduction of surgical checklists, wrong IOL incidents continue to occur and are probably under-reported. Human or behavioural factors are heavily implicated in these errors and need to be addressed by novel approaches, including simulation training. There is also scope to further improve the quality and detail of incident reporting and analysis to enhance patient safety.

Attention Strongly Modulates Reliability of Neural Responses to Naturalistic Narrative Stimuli

Attentional engagement is a major determinant of how effectively we gather information through our senses. Alongside the sheer growth in the amount and variety of information content that we are presented with through modern media, there is increased variability in the degree to which we "absorb" that information. Traditional research on attention has illuminated the basic principles of sensory selection to isolated features or locations, but it provides little insight into the neural underpinnings of our attentional engagement with modern naturalistic content. Here, we show in human subjects that the reliability of an individual's neural responses with respect to a larger group provides a highly robust index of the level of attentional engagement with a naturalistic narrative stimulus. Specifically, fast electroencephalographic evoked responses were more strongly correlated across subjects when naturally attending to auditory or audiovisual narratives than when attention was directed inward to a mental arithmetic task during stimulus presentation. This effect was strongest for audiovisual stimuli with a cohesive narrative and greatly reduced for speech stimuli lacking meaning. For compelling audiovisual narratives, the effect is remarkably strong, allowing perfect discrimination between attentional state across individuals. Control experiments rule out possible confounds related to altered eye movement trajectories or order of presentation. We conclude that reliability of evoked activity reproduced across subjects viewing the same movie is highly sensitive to the attentional state of the viewer and listener, which is aided by a cohesive narrative.

Severe Ocular Inflammation Following Ranibizumab or Aflibercept Injections for Age-Related Macular Degeneration: A Retrospective Claims Database Analysis

Purpose: Intravitreal injections of anti-vascular endothelial growth factor (VEGF) agents including ranibizumab and aflibercept are used to treat patients with ocular disorders such as neovascular age-related macular degeneration (nAMD); however, the injections are associated with rare instances of severe ocular inflammation. This study compared severe ocular inflammation rates in patients treated with ranibizumab versus aflibercept.

Methods: United States physician-level claims data covering an 18-month period for each therapy were analyzed. The primary analysis compared severe ocular inflammation event rates per 1000 injections. Sensitivity and subgroup analyses evaluated the impact of factors including intraocular surgery, intravitreal antibiotic administration, and previous intravitreal injections.

Results: The analysis included 432,794 injection claims (ranibizumab n = 253,647, aflibercept n = 179,147); significantly, more unique severe ocular inflammation events occurred in patients receiving aflibercept than ranibizumab (1.06/1000 injections, 95% confidence interval [CI], 0.91–1.21, vs. 0.64/1000 injections, 95% CI 0.54–0.74; p < 0.0001). Comparable results were observed for analyses of patients who had undergone glaucoma or cataract surgeries, had antibiotic-associated endophthalmitis, had non-antibiotic-associated endophthalmitis, and were non-treatment-naive. In contrast, no significant differences in severe ocular inflammation claims were recorded in treatment-naive patients who had no record of anti-VEGF treatment in the 6 months preceding the index claim. No significant change occurred in the rate of severe ocular inflammation claims over time following ranibizumab treatment.

Conclusions: Severe ocular inflammation was more frequent following intravitreal injection with aflibercept than with ranibizumab during routine clinical use in patients with nAMD. This highlights the importance of real-world, post-approval, observational monitoring of novel medicines, and may aid clinical decision-making, including choice of anti-VEGF agent.

Practice changes beta power at rest and its modulation during movement in healthy subjects but not in patients with Parkinson's disease

BACKGROUND

PD (Parkinson's disease) is characterized by impairments in cortical plasticity, in beta frequency at rest and in beta power modulation during movement (i.e., event-related ERS [synchronization] and ERD [desynchronization]). Recent results with experimental protocols inducing long-term potentiation in healthy subjects suggest that cortical plasticity phenomena might be reflected by changes of beta power recorded with EEG during rest. Here, we determined whether motor practice produces changes in beta power at rest and during movements in both healthy subjects and patients with PD. We hypothesized that such changes would be reduced in PD.

METHODS

We thus recorded EEG in patients with PD and age-matched controls before, during and after a 40-minute reaching task. We determined posttask changes of beta power at rest and assessed the progressive changes of beta ERD and ERS during the task over frontal and sensorimotor regions.

RESULTS

We found that beta ERS and ERD changed significantly with practice in controls but not in PD. In PD compared to controls, beta power at rest was greater over frontal sensors but posttask changes, like those during movements, were far less evident. In both groups, kinematic characteristics improved with practice; however, there was no correlation between such improvements and the changes in beta power.

CONCLUSIONS

We conclude that prolonged practice in a motor task produces use-dependent modifications that are reflected in changes of beta power at rest and during movement. In PD, such changes are significantly reduced; such a reduction might represent, at least partially, impairment of cortical plasticity.

The classic P300 encodes a build-to-threshold decision variable

The P300 component of the human event-related potential has been the subject of intensive experimental investigation across a five-decade period, owing to its apparent relevance to a wide range of cognitive functions and its sensitivity to numerous brain disorders, yet its exact contribution to cognition remains unresolved. Here, we carry out key analyses of the P300 elicited by transient auditory and visual targets to examine its potential role as a 'decision variable' signal that accumulates evidence to a decision bound. Consistent with the latter, we find that the P300 reaches a stereotyped amplitude immediately prior to response execution and that its rate of rise scales with target detection difficulty and accounts for trial-to-trial variance in RT. Computational simulations of an accumulation-to-bound decision process faithfully captured P300 dynamics when its parameters were set by model fits to the RT distributions. Thus, where the dominant explanatory accounts have conceived of the P300 as a unitary neural event, our data reveal it to be a dynamically evolving neural signature of decision formation. These findings place the P300 at the heart of a mechanistically principled framework for understanding decision-making in both the typical and atypical human brain.

Defining response to anti-VEGF therapies in neovascular AMD

The introduction of anti-vascular endothelial growth factor (anti-VEGF) has made significant impact on the reduction of the visual loss due to neovascular age-related macular degeneration (n-AMD). There are significant inter-individual differences in response to an anti-VEGF agent, made more complex by the availability of multiple anti-VEGF agents with different molecular configurations. The response to anti-VEGF therapy have been found to be dependent on a variety of factors including patient's age, lesion characteristics, lesion duration, baseline visual acuity (VA) and the presence of particular genotype risk alleles. Furthermore, a proportion of eyes with n-AMD show a decline in acuity or morphology, despite therapy or require very frequent re-treatment. There is currently no consensus as to how to classify optimal response, or lack of it, with these therapies. There is, in particular, confusion over terms such as 'responder status' after treatment for n-AMD, 'tachyphylaxis' and 'recalcitrant' n-AMD. This document aims to provide a consensus on definition/categorisation of the response of n-AMD to anti-VEGF therapies and on the time points at which response to treatment should be determined. Primary response is best determined at 1 month following the last initiation dose, while maintained treatment (secondary) response is determined any time after the 4th visit. In a particular eye, secondary responses do not mirror and cannot be predicted from that in the primary phase. Morphological and functional responses to anti-VEGF treatments, do not necessarily correlate, and may be dissociated in an individual eye. Furthermore, there is a ceiling effect that can negate the currently used functional metrics such as >5 letters improvement when the baseline VA is good (ETDRS>70 letters). It is therefore important to use a combination of both the parameters in determining the response.The following are proposed definitions: optimal (good) response is defined as when there is resolution of fluid (intraretinal fluid; IRF, subretinal fluid; SRF and retinal thickening), and/or improvement of >5 letters, subject to the ceiling effect of good starting VA. Poor response is defined as <25% reduction from the baseline in the central retinal thickness (CRT), with persistent or new IRF, SRF or minimal or change in VA (that is, change in VA of 0+4 letters). Non-response is defined as an increase in fluid (IRF, SRF and CRT), or increasing haemorrhage compared with the baseline and/or loss of >5 letters compared with the baseline or best corrected vision subsequently. Poor or non-response to anti-VEGF may be due to clinical factors including suboptimal dosing than that required by a particular patient, increased dosing intervals, treatment initiation when disease is already at an advanced or chronic stage), cellular mechanisms, lesion type, genetic variation and potential tachyphylaxis); non-clinical factors including poor access to clinics or delayed appointments may also result in poor treatment outcomes. In eyes classified as good responders, treatment should be continued with the same agent when disease activity is present or reactivation occurs following temporary dose holding. In eyes that show partial response, treatment may be continued, although re-evaluation with further imaging may be required to exclude confounding factors. Where there is persistent, unchanging accumulated fluid following three consecutive injections at monthly intervals, treatment may be withheld temporarily, but recommenced with the same or alternative anti-VEGF if the fluid subsequently increases (lesion considered active). Poor or non-response to anti-VEGF treatments requires re-evaluation of diagnosis and if necessary switch to alternative therapies including other anti-VEGF agents and/or with photodynamic therapy (PDT). Idiopathic polypoidal choroidopathy may require treatment with PDT monotherapy or combination with anti-VEGF. A committee comprised of retinal specialists with experience of managing patients with n-AMD similar to that which developed the Royal College of Ophthalmologists Guidelines to Ranibizumab was assembled. Individual aspects of the guidelines were proposed by the committee lead (WMA) based on relevant reference to published evidence base following a search of Medline and circulated to all committee members for discussion before approval or modification. Each draft was modified according to feedback from committee members until unanimous approval was obtained in the final draft. A system for categorising the range of responsiveness of n-AMD lesions to anti-VEGF therapy is proposed. The proposal is based primarily on morphological criteria but functional criteria have been included. Recommendations have been made on when to consider discontinuation of therapy either because of success or futility. These guidelines should help clinical decision-making and may prevent over and/or undertreatment with anti-VEGF therapy.

Electrophysiological indices of surround suppression in humans

Surround suppression is a well-known example of contextual interaction in visual cortical neurophysiology, whereby the neural response to a stimulus presented within a neuron's classical receptive field is suppressed by surrounding stimuli. Human psychophysical reports present an obvious analog to the effects seen at the single-neuron level: stimuli are perceived as lower-contrast when embedded in a surround. Here we report on a visual paradigm that provides relatively direct, straightforward indices of surround suppression in human electrophysiology, enabling us to reproduce several well-known neurophysiological and psychophysical effects, and to conduct new analyses of temporal trends and retinal location effects. Steady-state visual evoked potentials (SSVEP) elicited by flickering "foreground" stimuli were measured in the context of various static surround patterns. Early visual cortex geometry and retinotopic organization were exploited to enhance SSVEP amplitude. The foreground response was strongly suppressed as a monotonic function of surround contrast. Furthermore, suppression was stronger for surrounds of matching orientation than orthogonally-oriented ones, and stronger at peripheral than foveal locations. These patterns were reproduced in psychophysical reports of perceived contrast, and peripheral electrophysiological suppression effects correlated with psychophysical effects across subjects. Temporal analysis of SSVEP amplitude revealed short-term contrast adaptation effects that caused the foreground signal to either fall or grow over time, depending on the relative contrast of the surround, consistent with stronger adaptation of the suppressive drive. This electrophysiology paradigm has clinical potential in indexing not just visual deficits but possibly gain control deficits expressed more widely in the disordered brain.

Transformational change: nurses substituting for ophthalmologists for intravitreal injections - a quality-improvement report

BACKGROUND

The dramatic increase in need for anti-vascular endothelial growth factor (anti-VEGF) intravitreal therapy in the treatment of retinal disease and the absence of an equivalent increase in ophthalmologists to undertake such intravitreal injections created a patient-safety risk. Timing of intravitreal therapy (IVT) is critical to prevent vision loss and local clinics lacked capacity to treat patients appropriately. We aimed to improve capacity for IVT by nurse injections.

MATERIALS AND METHODS

A multidisciplinary prospective service-improvement process was undertaken at two adjacent general hospitals in the northwest of England. IVT injections by nurses were a principal component of solution development. After we had obtained appropriate institutional approval, experienced ophthalmic nurses were trained, supervised, and assessed to undertake IVT. Ophthalmologists directly supervised the first 200 injections, and a retina specialist was always on site.

RESULTS

Nurses undertook 3,355 intravitreal injections between June 2012 and November 2013, with minor adverse events (0.3% subconjunctival hemorrhage and corneal abrasion). There were no patient complaints at either hospital.

CONCLUSION

Experienced ophthalmic nurses quickly learned how to perform such injections safely. IVT by nurses was well accepted by patients and staff. Hospital A trained three nurses sequentially for improved flexibility in scheduling. Novel use of appropriately trained non-medical staff can improve efficiency and access in an overburdened service with time-sensitive disease. Retinal assessment was undertaken by ophthalmologists only. Improved access to IVT is important, as treatment with anti-VEGF therapy reduces blindness at population levels.

Intravitreal bevacizumab injection in unrecognised early pregnancy

PURPOSE

The use of intravitreal vascular endothelial growth factor (VEGF) inhibitor medications has widened considerably to include indications affecting females of reproductive age.

PATIENTS AND METHODS

We present our experiences following intravitreal injection of bevacizumab during the first trimester of unrecognised pregnancies in four women.

RESULTS

All our patients were inadvertently exposed to bevacizumab within the first trimester when placental growth and fetal organogenesis take place. There were three cases of pregnancy without complication and one case of complicated pregnancy in which there was a significant past obstetric history.

CONCLUSION

This case series provides further insights into intravitreal injection of bevacizumab in early pregnancy. There is insufficient information to suggest that such use is safe, nor is there definitive evidence to suggest that it causes harm. We advise that ophthalmologists discuss pregnancy with women of childbearing age undergoing intraocular anti-VEGF injections. Should a woman become pregnant, counselling is needed to explain the potential risks and benefits, and the limited available data relating to the use of these agents in early pregnancy.

'Toy' laser macular burns in children

PURPOSE

Laser 'toys' can be purchased online and imported with relative ease; the variety of such devices is a potential public safety concern. We describe five children with maculopathy following exposure to laser 'toys'.

METHODS

Case series of maculopathy following exposure to laser 'toys'.

RESULTS

Five children were seen in our Ophthalmic Unit with macular injuries following exposure to laser 'toys'. Clinically, three children had an acute vitelliform-like maculopathy which resolved to leave sub-foveal retinal pigment epithelium changes with reduced vision. One case was complicated by a choroidal neovascular membrane.

CONCLUSION

Laser 'toys', which resemble laser pointers, are increasingly available over the internet. Such 'toys' may not meet safety standards. Retinal injury in childhood following exposure to laser 'toys' is a public safety concern.