Multifocal electroretinograms in X-linked retinoschisis

Area of Science:

• Ophthalmology
• Retinal Diseases
• Visual Electrophysiology

Background:

• X-linked retinoschisis (XLRS) is a genetic disorder affecting retinal structure and function.
• Cone photoreceptors are crucial for detailed central and color vision.
• Understanding cone dysfunction in XLRS is vital for managing visual impairment.

Purpose of the Study:

• To investigate local retinal cone function in patients diagnosed with X-linked retinoschisis (XLRS).
• To utilize multifocal electroretinograms (mfERGs) for detailed functional assessment.
• To correlate mfERG findings with clinical macular and peripheral retinal findings.

Main Methods:

• mfERGs were recorded from seven patients (seven eyes) with XLRS.
• Stimulus array comprised 103 hexagons, with a total recording time of approximately 4 minutes.
• Analysis focused on amplitudes and implicit times of first- and second-order kernels for focal and summed responses.

Main Results:

• Markedly reduced first-order kernel amplitudes were observed in the central retina of all XLRS eyes.
• Significant delays in first-order kernel implicit times and more affected second-order kernels were noted across the entire field.
• Peripheral retinoschisis loci showed no significant difference in focal cone ERG amplitudes compared to adjacent normal areas.

Conclusions:

• Cone-mediated retinal responses are more impaired in the central than peripheral retina in XLRS.
• Widespread cone system dysfunction is suggested by delayed implicit times and reduced second-order kernels across the tested field.
• mfERG is a valuable tool for characterizing the extent of cone dysfunction in XLRS.