Electroretinography using contact lens electrode with built-in light source in dogs

Area of Science:

• Veterinary Ophthalmology
• Clinical Electrophysiology
• Retinal Function Testing

Background:

• Electroretinography (ERG) is crucial for diagnosing retinal diseases.
• Standard ERG recording in dogs is challenging without expensive equipment.
• The b/a ratio for retinal evaluation in dogs has not been previously reported.

Purpose of the Study:

• To establish a convenient and reproducible ERG recording method for dogs using a novel LED-electrode.
• To confirm the standard flash (SF) stimulus intensity for canine ERG.
• To evaluate the utility of the b/a ratio for assessing retinal function in dogs.

Main Methods:

• Developed and utilized a contact lens electrode with a built-in light source (LED-electrode).
• Performed ERG recordings on 15 healthy beagle dogs under sedation.
• Recorded rod and cone responses using defined standard flash (SF) intensities and analyzed the b/a ratio.

Main Results:

• Confirmed SF intensity of 3.0 cd/m(2)/sec (6,000 cd/m(2), 0.5 msec) yielding a b/a ratio of 2.
• Determined rod response intensity at 0.0096 cd/m(2)/sec (80 cd/m(2), 0.12 msec).
• Achieved smooth and reproducible ERG recordings under sedation without general anesthesia.

Conclusions:

• The LED-electrode facilitates quantitative and reproducible ERG examinations in dogs.
• The b/a ratio is proposed as a highly useful parameter for reporting ERG results in canine retinal evaluations.
• This method offers a more accessible approach to diagnosing retinal diseases in dogs.