Novel Insights in the Management of Vernal Keratoconjunctivitis (VKC): European Expert Consensus Using a Modified Nominal Group Technique.

INTRODUCTION: Vernal keratoconjunctivitis (VKC) is a rare, severe allergic ocular disease, typically occurring in children and adolescents, that can have a significant impact on quality of life and lead to visual impairment. Long-term treatment may be necessary to tackle chronic inflammation and topical corticosteroid dependency must be minimised due to the risk of complications. There is a need for unified clinical guidance to aid the assessment, diagnosis and management of VKC across Europe. The aim of this expert panel (the EUR-VKC Group) was to provide clear guidance for primary care physicians and general ophthalmologists involved in the diagnosis and management of VKC. METHODS: An expert group of seven European ophthalmologists was convened and a modified nominal group technique used to develop key recommendations on VKC management. The recommendations were subject to up to two rounds of voting using a 5-point Likert scale to ascertain consensus and the strength of each recommendation. Consensus was set at a predetermined threshold of ≥ 75.0% of experts selecting 'Strongly agree' or 'Agree'. RESULTS: A total of 47 recommendations were developed relating to the assessment of key of VKC, guidance on who and when to refer, as well as treatment-escalation pathways, long-term follow-up, and supportive care and education. All recommendations reached consensus after two rounds. The group emphasise how timely diagnosis and treatment initiation that is appropriate to disease severity are crucial to benefit patients with VKC. Patients with signs ('red flags') indicating severe VKC, or persistent mild-to-moderate VKC that is non-responsive following 2-4 weeks of treatment, should be referred to a sub-specialist. CONCLUSION: The EUR-VKC Group provides recommendations on the assessment, diagnosis, management, referral and follow-up of patients with VKC. It also provides a framework to facilitate collaboration between primary care physicians, general ophthalmologists and sub-specialists to improve the outcomes for patients with VKC.

Vernal keratoconjunctivitis (VKC) is a rare, underdiagnosed, chronic allergic eye disease that typically occurs in children and adolescents. If left untreated, VKC can significantly damage the eye, potentially leading to long-term complications, visual impairment and a reduced quality of life for the child and their family and/or caregivers. In the absence of established guidelines, this consensus programme set out to gather expert insights on best practices for assessing and managing VKC across Europe. A group of seven European ophthalmologists engaged in the consensus programme. A total of 47 recommendations were developed relating to the assessment, diagnosis, management, referral and follow-up of patients with VKC. These 47 recommendations underwent two rounds of review and were revised, if necessary, following expert input. Recommendations where ≥ 75.0% of experts agreed were considered as having reached consensus and were included as final recommendations. The experts agreed that VKC can be classified as mild, moderate or severe, and should be managed according to severity in a stepwise manner, with treatment intensity escalating as the disease severity increases. Timely diagnosis and treatment initiation appropriate to the severity of VKC are crucial to prevent sight loss and improve the quality of life of children with VKC. Ongoing treatment may be necessary to tackle the chronic inflammation associated with the disease and, therefore, reliance on steroid eye drops should be reduced to avoid an increased risk of well-known complications. The experts concluded that mild VKC can be assessed and managed in primary care, but patients with severe VKC, or with moderate-to-severe VKC that does not respond to treatment within 2­4 weeks, should be referred to a VKC specialist.

Brain damage serum biomarkers induced by COVID-19 in patients from northeast Brazil.

Neurological symptoms have been often reported in COVID-19 disease. In the present study, we evaluated brain damage associated with the increase of serum levels of neurological biomarkers S100B and neuron-specific enolase (NSE) induced by SARS-CoV-2 infection, in a population from Northeastern Brazil. Thirty-six healthy control (G1) individuals and 141 patients with confirmed COVID-19 were enrolled in this study. Positive-COVID-19 patients were divided into two groups according to the severity of illness by the National Institute of Health (NIH) criteria, 76 patients with mild symptoms for COVID-19 and (G2) and 65 with acute respiratory conditions requiring supplemental oxygenation via intensive care unit (ICU) admission (G3). A follow-up study was conducted with 23 patients from G2 14 (D14) and 21 (D21) days after the onset of symptoms. Serum levels of NSE and S100B were measured using the enzyme-linked immunoassay method (ELISA). Results revealed a significant positive association between G3 patients and S100B serum expression (p = 0.0403). The serum levels of NSE were also significantly enhanced in the G3 group compared to the control (p < 0.0001) and G2 group (p < 0.0001). In addition, clinical features such as symptoms and oxygenation status were not correlated with NSE or S100B serum expression. The follow-up study demonstrated a decrease over time (21 days) in NSE serum expression (p < 0.0001). These results suggest that brain damage is followed by acute virus exposure, with no long-term effects. Future work examining COVID-19 recovery will shed light on chronic neurological damage of SARS-CoV-2 infection.

Horizontal Gaze Palsy and Progressive Scoliosis in Dizygotic Twins.

Horizontal gaze palsy and progressive scoliosis (HGPPS) is a rare autosomal recessive disorder caused by mutations in the ROBO3 gene. Clinical presentation consists of impairment of conjugate horizontal eye movements together with a progressive scoliosis beginning in childhood. We report dizygotic twins with HGPPS that had absence of conjugate horizontal eye movements combined with divergent strabismus and synergistic divergence. One of them also had a congenital palpebral ptosis and vertical strabismus of the right eye. Onset of scoliosis occurred in childhood with rapid progression in the second decade of life. Brain imaging showed characteristic features of the disease such as hypoplasia of the pons and a midline cleft of the brainstem with a butterfly-like bifid appearance. Genetic analysis revealed a pathogenic homozygous mutation on the ROBO3 gene. These siblings and a previous report of two other individuals with the same disorder from the same small geographical region with less than 38000 inhabitants, likely represent a founder effect.

Amblyopia screening effectiveness at 3-4 years old: a cohort study.

OBJECTIVE: To study the effectiveness of amblyopia screening at ages 3-4. METHODS AND ANALYSIS: From a population with no previous screening, a cohort of 2300 children with 3-4 years old attending school (91% of children this age attend school in Portugal), were submitted to a complete ophthalmological evaluation. Amblyopia was diagnosed, treated and followed. Amblyopia prevalence, treatment effectiveness, absolute risk reduction (ARR), number needed to screen (NNS) and relative risk reduction (RRR) were estimated. RESULTS: Past/present history of amblyopia was higher than 3.1%-4.2%, depending on amblyopia definition normatives. Screening at age 3-4, had estimated ARR=2.09% (95% CI 1.50% to 2.68%) with a reduced risk of amblyopia in adulthood of 87% (RRR). NNS was 47.8 (95% CI 37.3 to 66.7). Treatment effectiveness of new diagnosis was 88% (83% if we include children already followed). 91% of new amblyopia diagnoses were refractive (of which 100% surpassed amblyopia Multi-Ethnic Pediatric Eye Disease Study criteria after treatment), while most strabismic amblyopias were already treated or undertreatment. Only 30% of children with refractive amblyopia risk factors that were not followed by an ophthalmologist, ended up having amblyopia at age 3-4. Eye patch was needed equally in new-diagnosis versus treated-earlier refractive amblyopia. CONCLUSIONS: Screening amblyopia in a whole-population setting at age 3-4 is highly effective. For each 48 children screened at age 3-4, one amblyopia is estimated to be prevented in the future (NNS). Screening earlier may lead to overdiagnosis and overtreatments: Treating all new diagnosis before age 3-4 would have a maximal difference in ARR of 0.3%, with the possible burden of as much as 70% children being unnecessary treated before age 3-4.Involving primary care, with policies for timely referral of suspicious/high-risk preverbal children, plus whole screening at age 3-4 seems a rational/effective way of controlling amblyopia.

SVEP1 as a Genetic Modifier of TEK-Related Primary Congenital Glaucoma.

Purpose: Affecting children by age 3, primary congenital glaucoma (PCG) can cause debilitating vision loss by the developmental impairment of aqueous drainage resulting in high intraocular pressure (IOP), globe enlargement, and optic neuropathy. TEK haploinsufficiency accounts for 5% of PCG in diverse populations, with low penetrance explained by variable dysgenesis of Schlemm's canal (SC) in mice. We report eight families with TEK-related PCG, and provide evidence for SVEP1 as a disease modifier in family 8 with a higher penetrance and severity. Methods: Exome sequencing identified coding/splice site variants with an allele frequency less than 0.0001 (gnomAD). TEK variant effects were assayed in construct-transfected HEK293 cells via detection of autophosphorylated (active) TEK protein. An enucleated eye from an affected member of family 8 was examined via histology. SVEP1 expression in developing outflow tissues was detected by immunofluorescent staining of 7-day mouse anterior segments. SVEP1 stimulation of TEK expression in human umbilical vascular endothelial cells (HUVECs) was measured by TaqMan quantitative PCR. Results: Heterozygous TEK loss-of-function alleles were identified in eight PCG families, with parent-child disease transmission observed in two pedigrees. Family 8 exhibited greater disease penetrance and severity, histology revealed absence of SC in one eye, and SVEP1:p.R997C was identified in four of the five affected individuals. During SC development, SVEP1 is secreted by surrounding tissues. SVEP1:p.R997C abrogates stimulation of TEK expression by HUVECs. Conclusions: We provide further evidence for PCG caused by TEK haploinsufficiency, affirm autosomal dominant inheritance in two pedigrees, and propose SVEP1 as a modifier of TEK expression during SC development, affecting disease penetrance and severity.

The Liberfarb syndrome, a multisystem disorder affecting eye, ear, bone, and brain development, is caused by a founder pathogenic variant in thePISD gene.

PURPOSE: We observed four individuals in two unrelated but consanguineous families from Portugal and Brazil affected by early-onset retinal degeneration, sensorineural hearing loss, microcephaly, intellectual disability, and skeletal dysplasia with scoliosis and short stature. The phenotype precisely matched that of an individual of Azorean descent published in 1986 by Liberfarb and coworkers. METHODS: Patients underwent specialized clinical examinations (including ophthalmological, audiological, orthopedic, radiological, and developmental assessment). Exome and targeted sequencing was performed on selected individuals. Minigene constructs were assessed by quantitative polymerase chain reaction (qPCR) and Sanger sequencing. RESULTS: Affected individuals shared a 3.36-Mb region of autozygosity on chromosome 22q12.2, including a 10-bp deletion (NM_014338.3:c.904-12_904-3delCTATCACCAC), immediately upstream of the last exon of the PISD (phosphatidylserine decarboxylase) gene. Sequencing of PISD from paraffin-embedded tissue from the 1986 case revealed the identical homozygous variant. In HEK293T cells, this variant led to aberrant splicing of PISD transcripts. CONCLUSION: We have identified the genetic etiology of the Liberfarb syndrome, affecting brain, eye, ear, bone, and connective tissue. Our work documents the migration of a rare Portuguese founder variant to two continents and highlights the link between phospholipid metabolism and bone formation, sensory defects, and cerebral development, while raising the possibility of therapeutic phospholipid replacement.

Accelerated age-related olfactory decline among type 1 Usher patients.

Usher Syndrome (USH) is a rare disease with hearing loss, retinitis pigmentosa and, sometimes, vestibular dysfunction. A phenotype heterogeneity is reported. Recent evidence indicates that USH is likely to belong to an emerging class of sensory ciliopathies. Olfaction has recently been implicated in ciliopathies, but the scarce literature about olfaction in USH show conflicting results. We aim to evaluate olfactory impairment as a possible clinical manifestation of USH. Prospective clinical study that included 65 patients with USH and 65 normal age-gender-smoking-habits pair matched subjects. A cross culturally validated version of the Sniffin' Sticks olfaction test was used. Young patients with USH have significantly better olfactory scores than healthy controls. We observe that USH type 1 have a faster ageing olfactory decrease than what happens in healthy subjects, leading to significantly lower olfactory scores in older USH1 patients. Moreover, USH type 1 patients showed significantly higher olfactory scores than USH type 2, what can help distinguishing them. Olfaction represents an attractive tool for USH type classification and pre diagnostic screening due to the low cost and non-invasive nature of the testing. Olfactory dysfunction should be considered among the spectrum of clinical manifestations of Usher syndrome.

Cross-cultural validation of a taste test with paper strips.

Taste dysfunctions influence food choices, interpersonal communication and danger/health. A gustometry protocol is the mainstream for clinical taste disorders diagnosis and suggests possible therapeutics. No clinical gustometry protocol has been adapted and validated to the Portuguese population so far. We aim to validate a gustometry protocol based on strips made from filter paper impregnated with different taste solutions. Four concentrations each for sweet, sour, salty and bitter were administered to 75 subjects. Hypogeusia threshold is of 4.8 in this population. Repeated measures indicated a good reliability and validity for the taste strips (ρ 75 = 0.68, p < 0.001). Although Mediterranean food implies a heathy eating pattern, taste threshold scores may be lower because of its habituation to natural food flavoring. The taste strip gustometry protocol can be applied to the clinical practice in Portugal. It is quick, effective and cheap. The diagnostic utility of this method is indisputable, as well as the advantages we can obtain with its application, for early diagnosis and distinction between disorders of taste and smell.

Genetic Analysis of 'PAX6-Negative' Individuals with Aniridia or Gillespie Syndrome.

We report molecular genetic analysis of 42 affected individuals referred with a diagnosis of aniridia who previously screened as negative for intragenic PAX6 mutations. Of these 42, the diagnoses were 31 individuals with aniridia and 11 individuals referred with a diagnosis of Gillespie syndrome (iris hypoplasia, ataxia and mild to moderate developmental delay). Array-based comparative genomic hybridization identified six whole gene deletions: four encompassing PAX6 and two encompassing FOXC1. Six deletions with plausible cis-regulatory effects were identified: five that were 3' (telomeric) to PAX6 and one within a gene desert 5' (telomeric) to PITX2. Sequence analysis of the FOXC1 and PITX2 coding regions identified two plausibly pathogenic de novo FOXC1 missense mutations (p.Pro79Thr and p.Leu101Pro). No intragenic mutations were detected in PITX2. FISH mapping in an individual with Gillespie-like syndrome with an apparently balanced X;11 reciprocal translocation revealed disruption of a gene at each breakpoint: ARHGAP6 on the X chromosome and PHF21A on chromosome 11. In the other individuals with Gillespie syndrome no mutations were identified in either of these genes, or in HCCS which lies close to the Xp breakpoint. Disruption of PHF21A has previously been implicated in the causation of intellectual disability (but not aniridia). Plausibly causative mutations were identified in 15 out of 42 individuals (12/32 aniridia; 3/11 Gillespie syndrome). Fourteen of these mutations presented in the known aniridia genes; PAX6, FOXC1 and PITX2. The large number of individuals in the cohort with no mutation identified suggests greater locus heterogeneity may exist in both isolated and syndromic aniridia than was previously appreciated.

Cultural Adaptation of the Portuguese Version of the "Sniffin' Sticks" Smell Test: Reliability, Validity, and Normative Data.

The cross-cultural adaptation and validation of the Sniffin`Sticks test for the Portuguese population is described. Over 270 people participated in four experiments. In Experiment 1, 67 participants rated the familiarity of presented odors and seven descriptors of the original test were adapted to a Portuguese context. In Experiment 2, the Portuguese version of Sniffin`Sticks test was administered to 203 healthy participants. Older age, male gender and active smoking status were confirmed as confounding factors. The third experiment showed the validity of the Portuguese version of Sniffin`Sticks test in discriminating healthy controls from patients with olfactory dysfunction. In Experiment 4, the test-retest reliability for both the composite score (r71 = 0.86) and the identification test (r71 = 0.62) was established (p<0.001). Normative data for the Portuguese version of Sniffin`Sticks test is provided, showing good validity and reliability and effectively distinguishing patients from healthy controls with high sensitivity and specificity. The Portuguese version of Sniffin`Sticks test identification test is a clinically suitable screening tool in routine outpatient Portuguese settings.

Continuing professional development: best practices.

Continuing professional development (CPD) involves not only educational activities to enhance medical competence in medical knowledge and skills, but also in management, team building, professionalism, interpersonal communication, technology, teaching, and accountability. This paper aims at reviewing best practices to promote effective CPD. Principles and guidelines, as already defined by some professional societies and world organizations, are emphasized as core actions to best enhance an effective lifelong learning after residency. The personal learning plan (PLP) is discussed as the core of a well-structured CPD and we describe how it should be created. Fundamental CPD principles and how they are integrated in the framework of every physician's professional life will be described. The value of systematic and comprehensive CPD documentation and assessment is emphasized. Accreditation requirements and professional relationships with commercial sponsors are discussed.

Abnormal late visual responses and alpha oscillations in neurofibromatosis type 1: a link to visual and attention deficits.

BACKGROUND: Neurofibromatosis type 1 (NF1) affects several areas of cognitive function including visual processing and attention. We investigated the neural mechanisms underlying the visual deficits of children and adolescents with NF1 by studying visual evoked potentials (VEPs) and brain oscillations during visual stimulation and rest periods. METHODS: Electroencephalogram/event-related potential (EEG/ERP) responses were measured during visual processing (NF1 n = 17; controls n = 19) and idle periods with eyes closed and eyes open (NF1 n = 12; controls n = 14). Visual stimulation was chosen to bias activation of the three detection mechanisms: achromatic, red-green and blue-yellow. RESULTS: We found significant differences between the groups for late chromatic VEPs and a specific enhancement in the amplitude of the parieto-occipital alpha amplitude both during visual stimulation and idle periods. Alpha modulation and the negative influence of alpha oscillations in visual performance were found in both groups. CONCLUSIONS: Our findings suggest abnormal later stages of visual processing and enhanced amplitude of alpha oscillations supporting the existence of deficits in basic sensory processing in NF1. Given the link between alpha oscillations, visual perception and attention, these results indicate a neural mechanism that might underlie the visual sensitivity deficits and increased lapses of attention observed in individuals with NF1.

Neural correlates of visual integration in Williams syndrome: gamma oscillation patterns in a model of impaired coherence.

Williams syndrome (WS) is a clinical model of dorsal stream vulnerability and impaired visual integration. However, little is still known about the neurophysiological correlates of perceptual integration in this condition. We have used a 3D structure-from-motion (SFM) integrative task to characterize the neuronal underpinnings of 3D perception in WS and to probe whether gamma oscillatory patterns reflect changed holistic perception. Coherent faces were parametrically modulated in 3D depth (three different depth levels) to vary levels of stimulus ambiguity. We have found that the electrophysiological (EEG/ERP) correlates of such holistic percepts were distinct across groups. Independent component analysis demonstrated the presence of a novel component with a late positivity around 200 ms that was absent in controls. Source localization analysis of ERP signals showed a posterior occipital shift in WS and reduced parietal dorsal stream sources. Interestingly, low gamma-band oscillations (20-40 Hz) induced by this 3D perceptual integration task were significantly stronger and sustained during the stimulus presentation in WS whereas high gamma-band oscillations (60-90 Hz) were reduced in this clinical model of impaired visual coherence, as compared to controls. These observations suggest that dorsal stream processing of 3D SFM stimuli has distinct neural correlates in WS and different cognitive strategies are employed by these patients to reach visual coherence. Importantly, we found evidence for the presence of different sub-bands (20-40 Hz/60-90 Hz) within the gamma range which can be dissociated concerning the respective role on the coherent percept formation, both in typical and atypical development.

Cryptic 7q36.2q36.3 deletion causes multiple congenital eye anomalies and craniofacial dysmorphism.

A patient with a de novo cryptic 7q36.2q36.3 deletion presented with multiple congenital eye abnormalities, short stature and craniofacial dysmorphism, in the absence of intellectual disability. This report further delineates the 7q36 microdeletion syndrome.

Gyrification, cortical and subcortical morphometry in neurofibromatosis type 1: an uneven profile of developmental abnormalities.

BACKGROUND: Neurofibromatosis type 1 (NF1) is a monogenic disorder associated with cognitive impairments. In order to understand how mutations in the NF1 gene impact brain structure it is essential to characterize in detail the brain structural abnormalities in patients with NF1. Previous studies have reported contradictory findings and have focused only on volumetric measurements. Here, we investigated the volumes of subcortical structures and the composite dimensions of the cortex through analysis of cortical volume, cortical thickness, cortical surface area and gyrification. METHODS: We studied 14 children with NF1 and 14 typically developing children matched for age, gender, IQ and right/left-handedness. Regional subcortical volumes and cortical gyral measurements were obtained using the FreeSurfer software. Between-group differences were evaluated while controlling for the increase in total intracranial volume observed in NF1. RESULTS: Subcortical analysis revealed disproportionately larger thalami, right caudate and middle corpus callosum in patients with NF1. Cortical analyses on volume, thickness and surface area were however not indicative of significant alterations in patients. Interestingly, patients with NF1 had significantly lower gyrification indices than typically developing children primarily in the frontal and temporal lobes, but also affecting the insula, cingulate cortex, parietal and occipital regions. CONCLUSIONS: The neuroanatomic abnormalities observed were localized to specific brain regions, indicating that particular areas might constitute selective targets for NF1 gene mutations. Furthermore, the lower gyrification indices were accompanied by a disproportionate increase in brain size without the corresponding increase in folding in patients with NF1. Taken together these findings suggest that specific neurodevelopmental processes, such as gyrification, are more vulnerable to NF1 dysfunction than others. The identified changes in brain organization are consistent with the patterns of cognitive dysfunction in the NF1 phenotype.

ATOH7 mutations cause autosomal recessive persistent hyperplasia of the primary vitreous.

The vertebrate basic helix-loop-helix (bHLH) transcription factor ATOH7 (Math5) is specifically expressed in the embryonic neural retina and is required for the genesis of retinal ganglion cells (RGCs) and optic nerves. In Atoh7 mutant mice, the absence of trophic factors secreted by RGCs prevents the development of the intrinsic retinal vasculature and the regression of fetal blood vessels, causing persistent hyperplasia of the primary vitreous (PHPV). We therefore screened patients with hereditary PHPV, as well as bilateral optic nerve aplasia (ONA) or hypoplasia (ONH), for mutations in ATOH7. We identified a homozygous ATOH7 mutation (N46H) in a large family with an autosomal recessive PHPV disease trait linked to 10q21, and a heterozygous variant (R65G, p.Arg65Gly) in one of five sporadic ONA patients. High-density single-nucleotide polymorphism analysis also revealed a CNTN4 duplication and an OTX2 deletion in the ONA cohort. Functional analysis of ATOH7 bHLH domain substitutions, by electrophoretic mobility shift and luciferase cotransfection assays, revealed that the N46H variant cannot bind DNA or activate transcription, consistent with structural modeling. The N46H variant also failed to rescue RGC development in mouse Atoh7-/- retinal explants. The R65G variant retains all of these activities, similar to wild-type human ATOH7. Our results strongly suggest that autosomal recessive persistent hyperplastic primary vitreous is caused by N46H and is etiologically related to nonsyndromic congenital retinal nonattachment. The R65G allele, however, cannot explain the ONA phenotype. Our study firmly establishes ATOH7 as a retinal disease gene and provides a functional basis to analyze new coding variants.

Distribution of potential suitable hammers and transport of hammer tools and nuts by wild capuchin monkeys.

Selection and transport of objects to use as tools at a distant site are considered to reflect planning. Ancestral humans transported tools and tool-making materials as well as food items. Wild chimpanzees also transport selected hammer tools and nuts to anvil sites. To date, we had no other examples of selection and transport of stone tools among wild nonhuman primates. Wild bearded capuchins (Cebus libidinosus) in Boa Vista (Piauí, Brazil) routinely crack open palm nuts and other physically well-protected foods on level surfaces (anvils) using stones (hammers) as percussive tools. Here we present indirect evidence, obtained by a transect census, that stones suitable for use as hammers are rare (study 1) and behavioral evidence of hammer transport by twelve capuchins (study 2). To crack palm nuts, adults transported heavier and harder stones than to crack other less resistant food items. These findings show that wild capuchin monkeys selectively transport stones of appropriate size and hardness to use as hammers, thus exhibiting, like chimpanzees and humans, planning in tool-use activities.

Evidence of widespread retinal dysfunction in patients with stargardt disease and morphologically unaffected carrier relatives.

PURPOSE: To characterize contrast sensitivity (CS) across the visual field for two achromatic spatial-temporal frequencies in 21 families with Stargardt disease (STGD) and to correlate psychophysical impairment with patterns of change in multifocal electroretinography (mfERG). METHODS: Twenty-seven eyes from patients with STGD, 16 eyes from asymptomatic relatives, and 44 age-matched control eyes were included. Chromatic CS function was assessed by comparing protan, deutan, and tritan (Cambridge Color Test; Cambridge Research Systems Ltd., Rochester, UK) and anomaloscope measures (IF-2; Roland Consult, Wiesbaden, Germany). Achromatic CS measures were obtained with custom-made software in nine locations by using randomly interleaved staircases. The first task-low spatial frequency (LSF)-matched the known frequency-doubling method that is believed to activate the magnocellular pathway preferentially. The second included an intermediate spatial frequency (ISF, 3.5 cyc/deg). mfERGs (RETIscan; Roland Consult) were also obtained. Relatives were screened for ABCA4 mutations by ABCR400 microarray and direct sequencing. RESULTS: Central impairment of achromatic and chromatic CS (along the three isolation axes) was observed in STGD. LSF and ISF tasks revealed significant and widespread dysfunction in patients and their morphologically unaffected relatives, 80% of whom were found to be ABCA4 mutation carriers. Significant reduction of P1 amplitudes was also observed in both groups. CONCLUSIONS: CS function is impaired in patients with STGD at distinct spatial-temporal frequencies, which, in addition to the color vision deficits, suggests dual impairment of the magno- parvocellular pathways. STGD morphologically unaffected carriers may show patterns of psychophysical dysfunction that are mirrored by abnormal mfERG responses.