Abstract
Purpose::
To validate a new bipolar fiber electrode prototype for clinical electroretinography.
Methods::
A recently developed prototype of a disposable bipolar fiber electrode (patent pending Brazilian Institute of Industrial Property # PI0602186-7), including one fiber for corneal signals and a second fiber serving as reference was tested in a group of 20 healthy volunteers (17-31 years; mean 22.7± 4.5; 8 males). All ISCEV rod and cone responses were recorded from a fully dilated pupil simultaneously in both eyes with a bipolar fiber electrode prototype in one randomly assigned eye and a DTL electrode in the other eye after 30 min of dark-adaptation. After presenting standard 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 ERG data acquisition and analysis. ERG outcomes were analyzed by Mann-Whitney test. A full ophthalmic assessment was performed in both eyes right after ERG session to evaluate possible adverse effects.
Results::
Responses recorded with bipolar fiber electrodes prototypes were comparable to DTL electrodes. On a qualitative analysis, the bipolar fiber electrode showed less amount of noise. On average, scotopic ERG amplitude and b-wave implicit time recorded using DTL were, respectively, 287.6µV and 36.3ms with similar findings for bipolar prototype (287.9µV and 36.3ms). Under photopic conditions DTL mean amplitude and implicit time were, respectively 108.9µV and 24.5ms with similar results for the bipolar prototype (116.4 µV and 24.5ms). No corneal abrasions or any other significant ophthalmic abnormalities were found after ERG recording with both types of electrodes.
Conclusions::
The new bipolar fiber electrode prototype is more affordable locally and provides stable and safe recordings of corneal electroretinograms compared to the gold standard DTL electrode. Separate normative values need to be collected for each type of electrode to accurately assess retinal function.
Keywords: electroretinography: clinical • electrophysiology: clinical • retina