Diagnostic contribution of visual electrophysiologic assessment in patients from a university hospital

PURPOSE: To determine the frequency of diagnostic categories obtained in a clinical vision electrophysiology laboratory at a university hospital. METHODS: Patients who underwent visual electrodiagnostic testing from October 1998 to October 2000 (N=570) were cross-sectionally studied. Electroretinogram (ERG) was performed in 385 (68%) patients and pattern and/or flash visually evoked potentials were performed in 185 (32%) patients. RESULTS: After electroretinogram assessment, the most frequently identified diagnostic categories were (in this order): retinitis pigmentosa, Stargardt's disease, cone dystrophy, cone-rod degeneration, retinotoxic effects due to several agents (chloroquine, tamoxifen, methanol, etc) and ocular trauma, besides unclear visual loss. In 23% of the cases, it was impossible to obtain a final diagnosis on the first examination. The largest group referred to electroretinogram testing was for documentation or exclusion of tapetoretinal degenerations (42%). In this group, 110 cases of RP were identified: 91 isolated and 19 syndromic cases. Visually evoked potential testing helped to identify the following diagnostic categories: diseases affecting only the optic nerve (optic nerve atrophy, optic neuritis, optic disk edema, etc); neurological conditions affecting the visual pathway (multiple sclerosis, cerebral palsy, blunt head trauma, tumors, etc): pediatric eye and/or neurological conditions (congenital cataract, cortical visual impairment, congenital glaucoma, etc) and opaque media (leucoma, ocular trauma, etc). CONCLUSIONS: Frequent and meaningful indications for visual electrophysiologic recording and diagnostic decisions arise from this relatively large group of studied patients. A number of diagnoses can hardly, if not all, be established without visual electrophysiologic testing. These include early stages of retinitis pigmentosa, progressive cone dystrophy, toxic retinopathy without fundus changes, optic nerve or retinal dysfunction in opaque media, optic nerve involvement in multiple sclerosis and pediatric eye disease with or without neurological damage.OBJETIVO: Determinar a freqüência de diferentes categorias diagnósticas em um laboratório de eletrofisiologia visual clínica de um hospital universitário. MÉTODOS: Os pacientes participaram de um estudo transversal sendo submetidos a testes eletrodiagnósticos visuais entre outubro de 1998 e outubro de 2000 (N=570). Os exames de eletrorretinografia (ERG) foram realizados em 385 pacientes (68%) e de potenciais visuais evocados (PVE) por reversão de padrão e/ou flashes e varredura em 185 pacientes (32%). RESULTADOS: Após avaliação da eletrorretinografia, as categorias diagnósticas mais freqüentes foram identificadas na seguinte ordem: retinose pigmentária, doença de Stargardt, distrofia de cones, degeneração do tipo cone-bastonete, retinotoxicidade devido a vários agentes (cloroquina, tamoxifeno, etc) e trauma ocular, além de perdas visuais de causas idiopáticas. Em 23% dos casos, não foi possível obter o diagnóstico final ao primeiro exame. O grupo mais freqüente referido para o eletrorretinografia foi para documentar ou excluir as degenerações tapeto-retinianas (42%). Neste grupo, 110 casos de retinose pigmentária foram identificados: 91 casos isolados e 19 sindrômicos. Para o exame de potenciais visuais evocados, as categorias diagnósticas mais freqüentes foram: doenças que afetam somente o nervo óptico (atrofia de nervo óptico, neurites ópticas, edema de disco óptico, etc.); condições neurológicas afetando a via visual (esclerose múltipla, paralisia cerebral, trauma crânio-encefálico, tumores, etc.), condições neurológicas e/ou doenças oculares pediátricas (catarata congênita, deficiência visual cortical, glaucoma congênito, etc.), e opacidade de meios (leucoma, trauma ocular, etc.). CONCLUSÕES: A análise deste amplo grupo de pacientes, mostra as indicações mais freqüentes e significativas para registros eletrofisiológicos visuais e decisões diagnósticas. Vários diagnósticos podem ser de difícil conclusão sem os testes eletrofisiológicos visuais. Dentre essas doenças incluem-se estágios iniciais da retinose pigmentária, distrofia progressiva de cones, retinopatia tóxica sem alterações fundoscópicas, função de nervo óptico ou retiniana em opacidades de meios, envolvimento de nervo óptico em esclerose múltipla e avaliação da acuidade visual em doenças oculares infantis com ou sem alterações neurológicas.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Universidade Federal de São Paulo (UNIFESP) Laboratório de Eletrofisiologia VisualUNIFESP, Laboratório de Eletrofisiologia VisualSciEL

Visual acuity and rod function in patients with retinitis pigmentosa

PURPOSE: To investigate visual acuity and rod function, and correlate them to different clinical parameters in patients with retinitis pigmentosa (RP). METHODS: A cohort of 199 patients with retinitis pigmentosa (110 males and 89 females), aged 6-79 years (mean = 36.8±17.5) had their monocular visual acuity measured by the ETDRS chart and rod function assessed by full-field electroretinogram and dark-adapted thresholds. The distribution of different genetic subtypes of retinitis pigmentosa was 20.3% autosomal dominant, 14.2% X - linked, 24.2% autosomal recessive and 41.3% isolated. History of consanguinity was found in 41 (20.6%) patients. Forty-one patients (20.6%) were 20 years old or less, 77 (38.6%) ranged from 21 - 40 years, 61 (30.7%) from 41 - 60 years, and 20 (10.1%) were 61 years or older. Peak-to-peak amplitude and b-wave implicit time were measured and statistically analyzed (one-way ANOVA). Pearson correlation was performed between rod amplitude and dark-adapted thereshold and rod amplitude and visual acuity. RESULTS: Analyzing the visual acuity data according to genetic subtypes, without considering age, showed that as a group, patients with autosomal recessive and isolated retinitis pigmentosa have less severe impairment of visual acuity, than those with X-linked retinitis pigmentosa. Nyctalopia begun earlier in X-linked groups, compared with the remaining groups (p=0.011). A negative correlation was found between dark-adapted thereshold and scotopic rod amplitude (Pearson correlation coefficient = - 0.772 and P =0.000). There were no significant relationships between visual acuity and rod response by electroretinogram (Pearson correlation coefficient = 0.0815 and P = 0.286), P > 0.050. CONCLUSIONS: In a cohort of retinitis pigmentosa patients, 31.2% had vision of 20/40 or better. Rod function loss was highly correlated when assessed electrophysiologically (ERG) and psychophysically (dark-adapted thershold). No correlation was found between rod response measured by electroretinogram and visual acuity.OBJETIVO: Investigar a acuidade visual e a função dos bastonetes e correlacioná-las com diferentes parâmetros clínicos freqüentemente observados em pacientes com retinose pigmentária (RP). MÉTODOS: Participaram deste estudo 199 pacientes com retinose pigmentária (110 homens e 89 mulheres), com idades variando entre 6 e 79 anos (média = 36,8±17,5), para avaliação da acuidade visual e da função de bastonetes obtidas pelo eletrorretinograma de campo total (ERG) e limiar de adaptação ao escuro (LAE). A distribuição dos diferentes subtipos genéticos da retinose pigmentária foi de 20,3% autossômica dominante, 14,2% ligada ao X , 24,2% autossômica recessiva e 41,3% isolada. Consangüinidade familiar positiva foi encontrada em 41 (20,6%) pacientes. Com relação à idade, 41 pacientes (20,6%) apresentavam idade inferior a 20 anos, 77 (38,6%) entre 21 - 40 anos, 61 (30,7%) entre 41 - 60 anos, e 20 (10,1%) apresentaram idade superior a 61 anos. A amplitude pico a pico e tempo de culminação da onda-b foram medidos e posteriormente analisados (ANOVA de uma via). A correlação de Pearson foi calculada entre amplitudes de bastonetes e o limiar de adaptação ao escuro e amplitude de bastonetes e acuidade visual. RESULTADOS: Analisando a acuidade visual de acordo com os sub-grupos de retinose pigmentária, sem levar em consideração a idade, obser-vamos que os pacientes com retinose pigmentária autossômica dominante, retinose pigmentária autossômica recessiva e retinose pigmentária isolada têm comprometimento da acuidade visual menor quando comparado a retinose pigmentária ligada ao X. A nictalopia teve início mais precocemente nos pacientes do subtipo retinose pigmentária ligada ao X quando comparada aos restantes (P = 0,0011). Correlação negativa foi obtida entre a perda de função de bastonetes medida pelo eletrorretinograma de campo total e pelo limiar de adaptação ao escuro (coeficiente de correlação de Pearson = - 0,772, P = 0,286, P> 0,050). CONCLUSÃO: Neste grupo de pacien-te com retinose pigmentária, 31,2% tiveram acuidade visual de 20/40 ou superior. A perda de função de bastonetes foi altamente correlacionada quando avaliada eletrofisiologicamente pelo eletrorretinograma de campo total e psicofisicamente pelo limiar de adaptação ao escuro. Não houve correlação entre a perda de função de bastonetes medida pelo eletrorretinograma e a acuidade visual.Universidade Federal de São Paulo (UNIFESP) Departamento de OftalmologiaUniversidade Federal de São Paulo (UNIFESP) Departamento de Oftalmologia Setor de Eletrofisiologia Visual ClínicaUniversidade Federal de São Paulo (UNIFESP) Departamento de Oftalmologia Laboratório de Eletrofisiologia Visual ClínicaUNIFESP, Depto. de OftalmologiaUNIFESP, Depto. de Oftalmologia Setor de Eletrofisiologia Visual ClínicaUNIFESP, Depto. de Oftalmologia Laboratório de Eletrofisiologia Visual ClínicaSciEL

Visual acuity and full-field electroretinography in patients with Usher's syndrome

PURPOSE: Usher's syndrome (US) is a group of genetically distinct autossomal conditions, characterized by sensorineural hearing loss accompanied by a retinal dystrophy indistinguishable from retinitis pigmentosa (RP). The purpose of this study was to analyze full-field electroretinography (ERG) and visual acuity (VA) among patients with type I and II Usher's syndrome. METHODS: Electroretinography responses and visual acuity were studied in 22 patients (mean age at test = 26.8±16.8 years). Seventeen patients had SU type I and 5 patients were diagnosed as Usher's syndrome type II. RESULTS: Mean visual acuity was 0.9 logMAR (20/160, Snellen equivalent) for patients with Usher's syndrome type I and 0.4 logMAR (20/50, Snellen equivalent) for patients with Usher's syndrome type II. Scotopic rod and maximal responses were non-detectable in both groups. Mean amplitude for oscillatory potentials was 14.5 µV ±6.1 in Usher's syndrome type I and 12.6 µV±5.2 in Usher's syndrome type II. Cone responses were non-detectable in 95% of the patients with Usher's syndrome I and in 100% of patients with Usher's syndrome II. Mean amplitude for 30 Hz flicker photopic cone response was 3.1 µV±4.1 for Usher's syndrome type I and 1.0 µV±0.6 for type II with mean implicit time of 34.0 ms±6.2 (US I) and 35.8 ms±3.1 (type II). CONCLUSIONS: Visual acuity was relatively preserved in both groups, however Usher's syndrome II group showed better visual acuity results. Electroretinography findings were severely reduced in both groups, with most patients showing non-detectable rod and cone responses.A síndrome de Usher (SU) é doença autossômica recessiva caracterizada por perda auditiva neuro-sensorial acompanhada de retinose pigmentária (RP). OBJETIVO: Analisar a eletrorretinografia de campo total (ERG) e a acuidade visual (AV) em pacientes com síndrome de Usher tipos I e II. MÉTODOS: Foram estudadas as respostas da eletrorretinografia de campo total e a acuidade visual de 22 pacientes (idade média = 26,8±16,8 anos). Destes, 17 tinham síndrome de Usher tipo I e 5 tinham síndrome de Usher tipo II. RESULTADOS: A acuidade visual média do grupo síndrome de Usher I foi de 0,9 logMAR (20/160, equivalente de Snellen) e do grupo síndrome de Usher II de 0,4 logMAR (20/50, equivalente de Snellen). As respostas dos bastonetes e as máximas respostas mostraram-se não detectáveis nos dois grupos. A amplitude média dos potenciais oscilatórios foi de 14,5 µV±6,1 na síndrome de Usher I e na síndrome de Usher II de 12,6 µV±5,2. As respostas de cones foram não detectáveis em 95% dos pacientes com síndrome de Usher I e em 100% dos pacientes com síndrome de Usher II. A amplitude média do flicker a 30 Hz nos pacientes com síndrome de Usher I foi de 3,1 µV±4,1 e do tempo de culminação de 34,0ms±6,2; nos pacientes com síndrome de Usher II a média de amplitude foi de 1,0 mV±0,6 e do tempo de culminação de 35,8 ms±3,1. CONCLUSÃO: A acuidade visual mostrou-se relativamente preservada nos dois grupos, porém com melhores resultados no grupo de síndrome de Usher II. Os achados eletrorretinográficos mostraram-se grandemente reduzidos em ambos os grupos, com a maioria dos pacientes apresentando respostas não detectáveis de bastonetes e cones.Universidade Federal de São Paulo (UNIFESP) Departamento de OftalmologiaUniversidade Federal de São Paulo (UNIFESP) Departamento de Oftalmologia Laboratório de Eletrofisiologia Visual ClínicaUniversidade Federal de São Paulo (UNIFESP)UNIFESP, Depto. de OftalmologiaUNIFESP, Depto. de Oftalmologia Laboratório de Eletrofisiologia Visual ClínicaUNIFESPSciEL

Visual acuity and retinal function in patients with Bardet-Biedl syndrome

OBJECTIVE: Bardet-Biedl syndrome is a genetic, multisystem disorder that causes severe visual impairment. This condition is characterized by retinal dystrophy, obesity, digit anomalies, renal disease, and hypogonadism. The purpose of this study was to analyze visual acuity and full-field electroretinogram findings in patients with the Bardet-Biedl syndrome phenotype. METHODS: The visual acuity of a group of 23 patients (15 males) with ages ranging from 6-36 years (mean = 15.8±6.4; median = 14.7) was assessed. Retinal function was evaluated by full-field electroretinography, and dark-adapted thresholds were assessed. RESULTS: Visual acuity in the better-seeing eye was 20/40 or better in 5 patients (21.7%), 20/50-20/150 in 13 (56.5%) patients, 20/200-20/400 in 2 (8.7%) patients and worse than 20/400 in one (4.3%) patient. The mean acuity in the better-seeing eye was 0.7±0.6 logMAR (20/100, Snellen equivalent). Scotopic rod and maximal responses were nondetectable in 21 (91.3%) patients, and cone responses were non-detectable in 15 (65.2%) patients. Elevated darkadapted visual thresholds were observed in all 19 patients who were able to be assessed, with 10 (52.6%) patients having thresholds greater than 30 dB. CONCLUSIONS: In a relatively young cohort of patients with Bardet-Biedl syndrome, only 21% had 20/40 or better vision. ERG scotopic responses were absent in the majority of cases, with cone responses being observed in less than half of cases. These findings showed the early deleterious effects in retinal function and visual acuity caused by this condition

Retinal function in patients with the neuronal ceroid lipofuscinosis phenotype

Purpose: To analyze the clinical features, visual acuity, and full-field electroretinogram (ERG) findings of 15 patients with the neuronal ceroid lipofuscinosis (NCL) phenotype and to establish the role of ERG testing in NCL diagnosis. Methods: The medical records of five patients with infantile NCL, five with Jansky-Bielschowsky disease, and five with juvenile NCL who underwent full-field ERG testing were retrospectively analyzed. Results: Progressive vision loss was the initial symptom in 66.7% of patients and was isolated or associated with ataxia, epilepsy, and neurodevelopmental involution. Epilepsy was present in 93.3% of patients, of whom 86.6% presented with neurodevelopmental involution. Fundus findings ranged from normal to pigmentary/atrophic abnormalities. Cone-rod, rod-cone, and both types of dysfunction were observed in six, one, and eight patients, respectively. Conclusion: In our study, all patients with the NCL phenotype had abnormal ERG findings, and the majority exhibited both cone-rod and rod-cone dysfunction. We conclude that ERG is a valuable tool for the characterization of visual dysfunction in patients with the NCL phenotype and is useful for diagnosis.Univ Fed Sao Paulo, Escola Paulista Med, Lab Eletrofisiol Visual Clin, Dept Oftalmol & Ciencias Visuais, Sao Paulo, SP, BrazilUniv Fed Sao Paulo, Escola Paulista Med, Lab Eletrofisiol Visual Clin, Dept Oftalmol & Ciencias Visuais, Sao Paulo, SP, BrazilWeb of Scienc