Noninvasive assessment of retinal function in rats using multifocal electroretinography

Area of Science:

• Ophthalmology
• Neuroscience
• Animal Models

Background:

• Rodent models are crucial for studying retinal diseases.
• Assessing retinal function in small-eyed animals presents unique challenges.
• Multifocal electroretinography (mfERG) is a potential tool for evaluating retinal function.

Purpose of the Study:

• To evaluate the applicability of multifocal electroretinograms (mfERGs) for functional assessment in rats.
• To determine the feasibility of using mfERGs in a small-eyed animal model with a rod-dominant retina.
• To explore the utility of mfERGs for modeling retinal diseases.

Main Methods:

• Noninvasive monocular mfERGs were recorded in anesthetized albino and pigmented rats.
• Achromatic stimuli were presented using a Visual Evoked Response Imaging System (VERIS).
• Stimulus parameters (rate, luminance) were varied to optimize recordings.

Main Results:

• mfERGs were successfully recorded from both albino and pigmented rats by adjusting stimulus presentation rates.
• Response amplitude and latency varied systematically with stimulus luminance and rate.
• The local nature of the mfERG response was confirmed through independent measures.

Conclusions:

• The study demonstrated the feasibility of using mfERG to assess topographical changes in the rat retina.
• Despite challenges (small eye, light scatter, stimulus adaptation), mfERGs can yield good signal-to-noise ratios in rats.
• This technique is applicable for evaluating retinal function in rodent models of disease.