Validation of a new fiber electrode prototype for clinical electroretinography

• Autor(a) principal: Berezovsky,Adriana
• Data de Publicação: 2008
• Outros Autores: Pereira,Josenilson Martins, Salomão,Solange Rios, Santos,Vagner Rogério dos, Schor,Paulo
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Arquivos brasileiros de oftalmologia (Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0004-27492008000300003
• topic: Electrodes; Electroretinography/instrumentation; Retina/physiology; Retinal diseases; Validation studies

PURPOSE: To validate a new fiber electrode prototype for clinical electroretinography (ERG). METHODS: A recently developed prototype of a disposable reference-coupled fiber electrode (patent pending Brazilian Institute of Industrial Property # PI0602186-7), including one fiber for corneal signals and a second fiber acting as reference was tested in a group of 20 healthy volunteers (17-31 years; mean 22.7 ± 4.5; 8 males). Standard electroretinography rod and cone responses were recorded from a fully dilated pupil simultaneously in both eyes with a reference-coupled fiber electrode prototype in one randomly assigned eye and a DTL® electrode in the other eye after 30 min of dark-adaptation. After presenting dark- and light-adapted stimuli, each response was analyzed for a- and b-wave amplitude and implicit time. The VERIS 5.1.9 system was used for electroretinography data acquisition and analysis. Electroretinography outcomes were analyzed by Mann-Whitney test. Slit-lamp examination was performed in both eyes right after electroretinography session to evaluate possible adverse effects. RESULTS: Responses recorded with reference-coupled fiber electrode prototypes were comparable to commercially available DTL® fiber electrodes. On a qualitative analysis, reference-coupled fiber electrodes provided recordings with less amount of noise. On average, scotopic electroretinography amplitude and b-wave implicit time recorded using DTL® were, respectively, 287.6 µV and 36.3 ms with similar findings for the reference-coupled fiber electrode prototype (287.9 µV and 36.3 ms). Under photopic conditions DTL® mean amplitude and implicit time were, respectively 108.9 µV and 24.5 ms with similar results for the reference-coupled fiber electrodes prototypes (116.4 µV and 24.5 ms). No corneal abrasions or any other significant adverse effects were found after electroretinography recording with both electrodes. CONCLUSIONS: The reference-coupled fiber electrode prototype provided stable and safe recordings of corneal electroretinograms compared to the commercially availabe DTL® electrode in healthy human subjects. The prototype is a feasible alternative instrument for clinical electroretinography recording to assess retinal function, however further analysis is recommended to validate its clinical usefulness in patients with retinal disorders.