Presynaptic Gq-coupled receptors drive biphasic dopamine transporter trafficking that modulates dopamine clearance and motor function.

Extracellular dopamine (DA) levels are constrained by the presynaptic DA transporter (DAT), a major psychostimulant target. Despite its necessity for DA neurotransmission, DAT regulation in situ is poorly understood, and it is unknown whether regulated DAT trafficking impacts dopaminergic signaling and/or behaviors. Leveraging chemogenetics and conditional gene silencing, we found that activating presynaptic Gq-coupled receptors, either hM3Dq or mGlu5, drove rapid biphasic DAT membrane trafficking in ex vivo striatal slices, with region-specific differences between ventral and dorsal striata. DAT insertion required D2 DA autoreceptors and intact retromer, whereas DAT retrieval required PKC activation and Rit2. Ex vivo voltammetric studies revealed that DAT trafficking impacts DA clearance. Furthermore, dopaminergic mGlu5 silencing elevated DAT surface expression and abolished motor learning, which was rescued by inhibiting DAT with a subthreshold CE-158 dose. We discovered that presynaptic DAT trafficking is complex, multimodal, and region specific, and for the first time, we identified cell autonomous mechanisms that govern presynaptic DAT tone. Importantly, the findings are consistent with a role for regulated DAT trafficking in DA clearance and motor function.

First implication of MIP in bilateral microphthalmia with persistent fetal vasculature.

Persistent fetal vasculature (PFV) is a rare malformative ocular disorder resulting from the failure of the hyaloid vasculature to regress. The severity of the visual impairment is depending on the underlying eye defects, ranging from discreet hyaloid remnants to severe ocular anomalies. Although PFV is generally unilateral, sporadic and idiopathic, a genetic cause has been described in some individuals, especially those presenting with a bilateral and/or syndromic form of PFV. The genes occasionally described in PFV are most often responsible for a wide spectrum of ocular phenotypes such as ATOH7 or NDP, a gene also known to be involved in Norrie disease, a X-linked vitreoretinopathy with extra-ocular features. We describe here a patient with an ocular phenotype consisting in non-syndromic bilateral PFV with cataract and microphthalmia, in whom a recurrent heterozygous de novo MIP disease-causing variant was detected after using a dedicated 119-ocular genes panel approach. Defects in the MIP gene are classically associated with dominant non-syndromic congenital cataract without other ocular malformative features. Thus, this case highlights the value of exploring individuals with PFV, even those with non-syndromic forms. It also broadens the phenotypic spectrum of the MIP gene, adding new insights into the gene networks underlying PFV pathophysiology, that remains unclear.

SYMPTOMATIC EARLY-ONSET X-LINKED RETINOSCHISIS: Clinical Presentation and Outcomes.

PURPOSE: To describe clinical characteristics and outcomes of children with early-onset X-linked retinoschisis. METHODS: In this retrospective consecutive case series, we included children diagnosed with symptomatic X-linked retinoschisis younger than 2 years. Presenting signs, clinical characteristics, treatments, and outcomes were recorded. RESULTS: Seven patients (14 eyes) with a mean age of 17.14 ± 6.28 months were included. Strabismus was the most common presenting symptom (6 of 7 patients, 86%). Clinical signs at the first diagnosis included peripheral retinoschisis in 13 eyes (13/14, 93%), of which 5 (5/13, 38%) were bullous, vitreous hemorrhage in 3 eyes (3/14, 21%), and retinal detachment in 3 eyes (3/14, 21%). The macula was involved in all eyes: It was detached in 2 eyes (2/14, 14%) and involved in the peripheral schisis in 4 eyes (4/14, 29%). In all remaining eyes, optical coherence tomography revealed foveoschisis. Six eyes (6/14, 42%) received surgery. At the last follow-up, visual acuity, when available, ranged from no light perception to 20/40, and no children had persistent retinal detachment. CONCLUSION: Children with early-onset X-linked retinoschisis had severe forms. All children had peripheral retinoschisis which was often bullous and extended to the macula. Diagnosis is often clinical but handheld optical coherence tomography can be helpful in atypical forms. Complications requiring surgical management are frequent.

Predictive factors of graft detachment and rebubbling after descemet membrane endothelial keratoplasty.

PURPOSE: To identify risk and predictive factors associated with the need of rebubbling in the eye of patients who underwent a descemet membrane endothelial keratoplasty (DMEK). METHODS: The records of patients who underwent DMEK were retrospectively analyzed. Data regarding comorbidities, intraoperative characteristics, and postoperative treatments or complications were collected. The central corneal thickness (CCT) was measured by optical coherence tomography before and the day after DMEK. Univariate and multivariate analyses were performed. RESULTS: Of the 333 DMEK, rebubbling was performed in 119 cases (36%). Preoperative subepithelial fibrosis and a history of penetrating keratoplasty (PK) were associated with significantly more graft detachment [OR of 3.55 (2.02-6.32; P < 0.001) and 5.89 (2.00-21.86; P = 0.003), respectively]. A decreased CCT the day after surgery reduced by 5.7-fold the risk of rebubbling (sensitivity/specificity of 0.42/0.93). Conversely, a 20% increase in the CCT the day after surgery increased by 4.5-fold the risk of rebubbling (sensitivity/specificity of 0.42/0.91). CONCLUSION: Variation of the CCT could be used as a predictive factor of rebubbling after DMEK. Patients with a 20% increase of CCT the day after surgery are at higher risk of graft detachment. Conversely, a reduced CCT the day after the surgery is associated with a reduced risk of rebubbling. Subepithelial fibrosis and history of PK were also identified as risk factors for rebubbling. Those predictive factors may help develop a customized approach for patients undergoing DMEK surgery.

Comparison of qPCR and Metabarcoding Methods as Tools for the Detection of Airborne Inoculum of Forest Fungal Pathogens.

Forest diseases caused by invasive fungal pathogens are becoming more common, sometimes with dramatic consequences to forest ecosystems. The development of early detection systems is necessary for efficient surveillance and to mitigate the impact of invasive pathogens. Windborne spores are an important pathway for introduction of fungal pathogens into new areas; the design of spore trapping devices adapted to forests, capable of collecting different types of spores, and aligned with development of efficient molecular methods for detection of the pathogen, should help forest managers anticipate new disease outbreaks. Two types of Rotorod samplers were evaluated for the collection of airborne inoculum of forest fungal pathogens with a range of spore sizes in five forest types. Detection was by specific quantitative PCR (qPCR) and by high-throughput sequencing (HTS) of amplified internal transcribed spacer sequences using a new bioinformatic pipeline, FungiSearch, developed for diagnostic purposes. Validation of the pipeline was conducted on mock communities of 10 fungal species belonging to different taxa. Although the sensitivity of the new HTS pipeline was lower than the specific qPCR, it was able to detect a wide variety of fungal pathogens. FungiSearch is easy to use, and the reference database is updatable, making the tool suitable for rapid identification of new pathogens. This new approach combining spore trapping and HTS detection is promising as a diagnostic tool for invasive fungal pathogens.

Pediatric endophthalmitis: clinical profile, outcomes, and a proposed protocol.

PURPOSE: To investigate the clinical profile and visual outcomes of infectious endophthalmitis in children at a single tertiary hospital in France, and propose an evidence-based protocol for management. METHODS: This is a retrospective monocentric study that involved children with a history of endophthalmitis between January 2008 and January 2020. The clinical characteristics, etiology, microbiological spectrum from aqueous/vitreous tab, anatomical and visual outcomes, and management were analyzed. The Fischer and chi-square tests were used in the statistical evaluation. RESULTS: Twenty-six children were eligible for inclusion. The mean patients age at presentation was 4.2 years (range, 8 days-14.3 years). With regard to etiology, patients were divided into posttraumatic group (n = 7 (26.9%)), postoperative group (n = 15 (57.7%)), endogenous group (n = 3 (11.5%)), and infectious corneal ulcer group (n = 1 (3.9%)). Time-to-onset of symptoms was highest in children ≤ 3 years old and in the postoperative subgroup who had at least one glaucoma procedure. Microbiology results showed growth in 12/26 (46.2%). The most common microorganism identified was Streptococcus pneumoniae (5/12 (41.7%)). The antibiotic regimen varied depending on age, organism, and sensitivities. The final visual outcomes were 20/200 or better in 11/26 (42.3%) eyes, and 13/26 (50.0%) eyes had no light perception. Twelve of twenty-six (46.2%) eyes ended up with phthisis bulbi. CONCLUSION: Pediatric endophthalmitis is a rare but devastating condition with poor visual prognosis, requiring prompt recognition and treatment. Despite aggressive management with antibiotics and vitrectomy, the visual prognosis is generally poor. A protocol for management with an adapted systemic antibiotic therapy is proposed in order to improve outcomes.

Dopamine Receptors Differentially Control Binge Alcohol Drinking-Mediated Synaptic Plasticity of the Core Nucleus Accumbens Direct and Indirect Pathways.

Binge alcohol drinking, a behavior characterized by rapid repeated alcohol intake, is most prevalent in young adults and is a risk factor for excessive alcohol consumption and alcohol dependence. Although the alteration of synaptic plasticity is thought to contribute to this behavior, there is currently little evidence that this is the case. We used drinking in the dark (DID) as a model of binge alcohol drinking to assess its effects on spike timing-dependent plasticity (STDP) in medium spiny neurons (MSNs) of the core nucleus accumbens (NAc) by combining patch-clamp recordings with calcium imaging and optogenetics. After 2 weeks of daily alcohol binges, synaptic plasticity was profoundly altered. STDP in MSNs expressing dopamine D1 receptors shifted from spike-timing-dependent long-term depression (tLTD), the predominant form of plasticity in naive male mice, to spike-timing-dependent long-term potentiation (tLTP) in DID mice, an effect that was totally reversed in the presence of 4 µm SCH23390, a dopamine D1 receptor antagonist. In MSNs presumably expressing dopamine D2 receptors, tLTP, the main form of plasticity in naive mice, was inhibited in DID mice. Interestingly, 1 µm sulpiride, a D2 receptor antagonist, restored tLTP. Although we observed no alterations of AMPA and NMDA receptor properties, we found that the AMPA/NMDA ratio increased at cortical and amygdaloid inputs but not at hippocampal inputs. Also, DID effects on STDP were accompanied by lower dendritic calcium transients. These data suggest that the role of dopamine in mediating the effects of binge alcohol drinking on synaptic plasticity of NAc MSNs differs markedly whether these neurons belong to the direct or indirect pathways.SIGNIFICANCE STATEMENT We examined the relationship between binge alcohol drinking and spike timing-dependent plasticity in nucleus accumbens (NAc) neurons. We found that repeated drinking bouts modulate differently synaptic plasticity in medium spiny neurons of the accumbens direct and indirect pathways. While timing-dependent long-term depression switches to long-term potentiation (LTP) in the former, timing-dependent LTP is inhibited in the latter. These effects are not accompanied by changes in AMPA and NMDA receptor properties at cortical, amygdaloid, and hippocampal synapses. Interestingly, dopamine D1 and D2 receptor antagonists have opposite effects on plasticity. Our data show that whether core NAc medium spiny neurons belong to the direct or indirect pathways determines the form of spike timing-dependent plasticity (STDP), the manner by which STDP responds to binge alcohol drinking, and its sensitivity to dopamine receptor antagonists.

Acoustic Transducers as Passive Cooperative Targets for Wireless Sensing of the Sub-Surface World: Challenges of Probing with Ground Penetrating RADAR.

Passive wireless transducers are used as sensors, probed by a RADAR system. A simple way to separate the returning signal from the clutter is to delay the response, so that the clutter decays before the echoes are received. This can be achieved by introducing a fixed delay in the sensor design. Acoustic wave transducers are ideally suited as cooperative targets for passive, wireless sensing. The incoming electromagnetic pulse is converted into an acoustic wave, propagated on the sensor substrate surface, and reflected as an electromagnetic echo. According to a known law, the acoustic wave propagation velocity depends on the physical quantity under investigation, which is then measured as an echo delay. Both conversions between electromagnetic and acoustic waves are based on the piezoelectric property of the substrate of which the sensor is made. Investigating underground sensing, we address the problems of using GPR (Ground-Penetrating RADAR) for probing cooperative targets. The GPR is a good candidate for this application because it provides an electromagnetic source and receiver, as well as echo recording tools. Instead of designing dedicated electronics, we choose a commercially available, reliable and rugged instrument. The measurement range depends on parameters like antenna radiation pattern, radio spectrum matching between GPR and the target, antenna-sensor impedance matching and the transfer function of the target. We demonstrate measurements at depths ranging from centimeters to circa 1 m in a sandbox. In our application, clutter rejection requires delays between the emitted pulse and echoes to be longer than in the regular use of the GPR for geophysical measurements. This delay, and the accuracy needed for sensing, challenge the GPR internal time base. In the GPR units we used, the drift turns out to be incompatible with the targeted application. The available documentation of other models and brands suggests that this is a rather general limitation. We solved the problem by replacing the analog ramp generator defining the time base with a fully digital solution, whose time accuracy and stability relies on a quartz oscillator. The resulting stability is acceptable for sub-surface cooperative sensor measurement.

Large conductance voltage- and Ca2+-gated potassium (BK) channel ß4 subunit influences sensitivity and tolerance to alcohol by altering its response to kinases.

Tolerance is a well described component of alcohol abuse and addiction. The large conductance voltage- and Ca(2+)-gated potassium channel (BK) has been very useful for studying molecular tolerance. The influence of association with the ß4 subunit can be observed at the level of individual channels, action potentials in brain slices, and finally, drinking behavior in the mouse. Previously, we showed that 50 mm alcohol increases both α and αß4 BK channel open probability, but only α BK develops acute tolerance to this effect. Currently, we explore the possibility that the influence of the ß4 subunit on tolerance may result from a striking effect of ß4 on kinase modulation of the BK channel. We examine the influence of the ß4 subunit on PKA, CaMKII, and phosphatase modulation of channel activity, and on molecular tolerance to alcohol. We record from human BK channels heterologously expressed in HEK 293 cells composed of its core subunit, α alone (Insertless), or co-expressed with the ß4 BK auxiliary subunit, as well as, acutely dissociated nucleus accumbens neurons using the cell-attached patch clamp configuration. Our results indicate that BK channels are strongly modulated by activation of specific kinases (PKA and CaMKII) and phosphatases. The presence of the ß4 subunit greatly influences this modulation, allowing a variety of outcomes for BK channel activity in response to acute alcohol.

How reliable is metabarcoding for pollen identification? An evaluation of different taxonomic assignment strategies by cross-validation.

Metabarcoding is a powerful tool, increasingly used in many disciplines of environmental sciences. However, to assign a taxon to a DNA sequence, bioinformaticians need to choose between different strategies or parameter values and these choices sometimes seem rather arbitrary. In this work, we present a case study on ITS2 and rbcL databases used to identify pollen collected by bees in Belgium. We blasted a random sample of sequences from the reference database against the remainder of the database using different strategies and compared the known taxonomy with the predicted one. This in silico cross-validation (CV) approach proved to be an easy yet powerful way to (1) assess the relative accuracy of taxonomic predictions, (2) define rules to discard dubious taxonomic assignments and (3) provide a more objective basis to choose the best strategy. We obtained the best results with the best blast hit (best bit score) rather than by selecting the majority taxon from the top 10 hits. The predictions were further improved by favouring the most frequent taxon among those with tied best bit scores. We obtained better results with databases containing the full sequences available on NCBI rather than restricting the sequences to the region amplified by the primers chosen in our study. Leaked CV showed that when the true sequence is present in the database, blast might still struggle to match the right taxon at the species level, particularly with rbcL. Classical 10-fold CV-where the true sequence is removed from the database-offers a different yet more realistic view of the true error rates. Taxonomic predictions with this approach worked well up to the genus level, particularly for ITS2 (5-7% of errors). Using a database containing only the local flora of Belgium did not improve the predictions up to the genus level for local species and made them worse for foreign species. At the species level, using a database containing exclusively local species improved the predictions for local species by ∼12% but the error rate remained rather high: 25% for ITS2 and 42% for rbcL. Foreign species performed worse even when using a world database (59-79% of errors). We used classification trees and GLMs to model the % of errors vs. identity and consensus scores and determine appropriate thresholds below which the taxonomic assignment should be discarded. This resulted in a significant reduction in prediction errors, but at the cost of a much higher proportion of unassigned sequences. Despite this stringent filtering, at least 1/5 sequences deemed suitable for species-level identification ultimately proved to be misidentified. An examination of the variability in prediction accuracy between plant families showed that rbcL outperformed ITS2 for only two of the 27 families examined, and that the % correct species-level assignments were much better for some families (e.g. 95% for Sapindaceae) than for others (e.g. 35% for Salicaceae).

Dopamine control of social novelty preference is constrained by an interpeduncular-tegmentum circuit.

Animals are inherently motivated to explore social novelty cues over familiar ones, resulting in a novelty preference (NP), although the behavioral and circuit bases underlying NP are unclear. Combining calcium and neurotransmitter sensors with fiber photometry and optogenetics in mice, we find that mesolimbic dopamine (DA) neurotransmission is strongly and predominantly activated by social novelty controlling bout length of interaction during NP, a response significantly reduced by familiarity. In contrast, interpeduncular nucleus (IPN) GABAergic neurons that project to the lateral dorsal tegmentum (LDTg) were inhibited by social novelty but activated during terminations with familiar social stimuli. Inhibition of this pathway during NP increased interaction and bout length with familiar social stimuli, while activation reduced interaction and bout length with novel social stimuli via decreasing DA neurotransmission. These data indicate interest towards novel social stimuli is encoded by mesolimbic DA which is dynamically regulated by an IPN→LDTg circuit to control NP.

Enhancing Buprestidae monitoring in Europe: Trap catches increase with a fluorescent yellow colour but not with the presence of decoys.

This study investigated the efficacy of various traps differing in colour (green or yellow), presence or absence of decoys (dead Agrilus planipennis) or design (commercial MULTz or multifunnel traps, and homemade bottle- or fan-traps) for monitoring European Buprestidae in deciduous forests and pear orchards. Over two years, we collected 2220 samples on a two-week basis from 382 traps across 46 sites in Belgium and France. None of the traps proved effective for monitoring Agrilus sinuatus in infested pear orchards (17 specimens captured in 2021, 0 in 2022). The decoys did not affect the catch rates whatever the trap model, colour, buprestid species or sex. The fluorescent yellow traps (MULTz and yellow fan-traps) tended to be more attractive than the green traps (green fan-traps and, to a lower extent, multifunnel green traps). Most Agrilus species showed similar patterns in mean trap catches, with the exception of Agrilus biguttatus, which had the largest catches in the green multifunnel traps. Finally, we observed a high variation in catch rates between localities: the site explained 64% of the catches variance, while the tree within the site and the type of trap explained only 6-8.5% each. In many sites, we captured very few specimens, despite the abundance of dying mature trees favourable to the development of Buprestidae. For the early detection of non-native Buprestidae, it therefore seems essential to maximise the number of monitoring sites. Due to their cost-effectiveness, lightweight design, and modularity, fan-traps emerged as promising tools for buprestid monitoring. The study's findings extend beyond European fauna, as a preliminary trial in Canada suggested that yellow fan-traps could also improve captures of non-European buprestid species and catch species of interest such as Agrilus bilineatus (a species on the EPPO A2 list of pests/pathogens recommended for regulation in the EU).

Incidence and Outcomes of Eye Trauma Associated With Recreative Use of Nonpowder Toy Guns: A 12-Year Retrospective Study.

PURPOSE: Nonpowder toy guns (NPTGs) are responsible for many ocular traumas. This study aims to detail the outcomes of these injuries depending on the causative NPTG. DESIGN: Retrospective, observational case series. METHODS: Cases of NPTG-associated ocular trauma managed in a Parisian eye emergency department between August 1, 2010, and January 1, 2023, were reviewed. The date of trauma, causative NPTG, patient demographics, initial and follow-up eye examinations, any surgical procedure, and visual outcomes for each ocular trauma were analyzed. RESULTS: Over 12 years, NPTGs were responsible for 324 eye injuries and 980 visits. Patients were mostly male (77.5%), and mean age at trauma was 16.2 years. Foam bullets or foam dart blasters accounted for 54.9% of traumas and were mainly responsible for corneal injuries and hyphema (30.9% and 27%, respectively). BB guns and airsoft guns were frequently responsible for anterior segment lesions, as well as intravitreal hemorrhages (14.7%) and commotio retinae (21.1%). Paintball guns accounted for the largest proportion of posterior segment lesions (eg, intraretinal or subretinal hemorrhages leading to macular atrophy/contusion maculopathy), and one-third of casualties had undergone ocular surgery. Among all traumas, final visual acuity was lower than 20/200 in 6.5% of cases. Phthisis occurred in 8 cases: Two were related to foam bullets or foam dart blaster injuries (1 contusion and 1 rupture), 2 other cases followed a rupture due to BB guns/airsoft guns, 1 case occurred after a rupture related to a paintball gunshot, and 3 others were due to other types of compressed air guns (1 rupture, 1 intraocular foreign body, and 1 total retinal detachment). CONCLUSIONS: NPTG-related ocular trauma outcomes differ according to the causative toy. Paintball guns and BB guns/airsoft gun-related traumas were more likely to be associated with severe lesions, but an increasing number of ocular injuries related to the use of foam bullets or foam dart blasters are reported in younger and younger children. Public health policies should promote the use of protective eyewear.

Modulation of neuronal excitability by binge alcohol drinking.

Drug use poses a serious threat to health systems throughout the world. The number of consumers rises every year being alcohol the drug of abuse most consumed causing 3 million deaths (5.3% of all deaths) worldwide and 132.6 million disability-adjusted life years. In this review, we present an up-to-date summary about what is known regarding the global impact of binge alcohol drinking on brains and how it affects the development of cognitive functions, as well as the various preclinical models used to probe its effects on the neurobiology of the brain. This will be followed by a detailed report on the state of our current knowledge of the molecular and cellular mechanisms underlying the effects of binge drinking on neuronal excitability and synaptic plasticity, with an emphasis on brain regions of the meso-cortico limbic neurocircuitry.

Cystoid macular oedema after descemet membrane endothelial keratoplasty.

AIMS: To determine the incidence and risk factors of cystoid macular oedema (CMO) following descemet membrane endothelial keratoplasty (DMEK) with or without combined cataract surgery (triple-DMEK). METHODS: We reviewed the records of patients who underwent DMEK surgery alone or triple-DMEK performed at the Rothschild Foundation Hospital (Paris, France) between January 2019 and March 2020. Patients with pre-existing CMO observed on the preoperative macular optical coherence tomography (OCT) were excluded. Spectral-domain OCT was performed in patients with postoperative visual impairment. Data regarding comorbidities, intraoperative characteristics and postoperative treatments or complications were collected and analysed. Univariate and multivariate analyses were performed. RESULTS: Twenty three of 246 eyes (9.36%) developed clinically significant (cs)-CMO after DMEK. Triple-DMEK was not associated with a higher risk to develop CMO (12.2% in DMEK alone and 6.1% in triple-DMEK). Pseudophakic bullous keratopathy (PBK ; 39.1% vs 9%; OR=3.5 (1.0 to 11.8), p=0.045) and epiretinal membrane (ERM; 39.1% vs 7.7%; OR=10.5 (3.4 to 32.3), p<0.001) were more frequently observed in patients who developed CMO. The occurrence of hyphaema during surgery was statistically associated with postoperative CMO (13% vs 1.3%; OR=7.1 (1.0 to 48.8) p=0.045). Peroperative epithelial debridement was statistically associated with postoperative CMO (65.2% vs 33.2%, p=0.005), but only in univariate analysis. CONCLUSIONS: We identified a clinically significant CMO incidence of 9.35% after DMEK. Patients with a history of ERM, PBK and intraoperative hyphaema may be at risk of developing CMO after DMEK surgery and should be monitored.

Specificities of pediatric ocular emergencies before and during the COVID-19 era: A retrospective comparative study in an eye-related emergency department in Paris.

INTRODUCTION: Epidemiological data on the use of eye-related emergency services by children are limited. The objective of this study was to determine how COVID-19 affected the epidemiological trends of pediatric ocular emergencies. METHODS: We performed a retrospective chart review of children under the age of 18 years who visited our eye-related emergency department between March 17 and June 7, 2020 and between March 18 and June 9, 2019. This was a descriptive and comparative analysis of the two study periods based on the demographic characteristics of patients and the diagnosis reported by the ophthalmologist in the digital medical charts. One of the investigators performed a second reading of the files to homogenize the diagnosis classification based on the most frequently found items. RESULTS: In total, 754 children were seen in our eye-related emergency department during the 2020 study period versus 1399 in 2019, representing a 46% decrease. In 2019, the four main diagnoses were traumatic injury (30%), allergic conjunctivitis (15%), infectious conjunctivitis (12%), and chalazion/blepharitis (12%). In the 2020 study period there was a significant decrease in the proportion of patients presenting with traumatic injuries (p < 0.001), infectious conjunctivitis (p = 0.03), and chalazion/blepharitis (p < 0.001). Consultations for chalazion/blepharitis were the most affected by the pandemic, followed by traumatic injuries (-72% and -64%, respectively). The proportion of patients who required surgery after trauma was higher in 2020 than in 2019 (p < 0.01), but the absolute number of severe trauma cases remained stable. CONCLUSIONS: The COVID-19 pandemic was accompanied by a decrease in the overall use of a pediatric eye-related emergency services in Paris. Visits due to benign causes and ocular trauma also decreased, but visits for more severe pathologies were not affected. Longer-term epidemiological studies may confirm or refute a change in eye emergency department use habits.