Waveform changes of the first-order multifocal electroretinogram in patients with glaucoma

Area of Science:

• Ophthalmology
• Neuroscience
• Medical Imaging

Background:

• Glaucoma is a progressive optic neuropathy leading to characteristic visual field loss.
• The multifocal electroretinogram (M-ERG) is a diagnostic tool used to assess retinal function.

Purpose of the Study:

• To investigate the relationship between components of the first-order multifocal electroretinogram (M-ERG) and glaucomatous visual field loss.
• To determine if M-ERG amplitudes or implicit times correlate with visual field sensitivity in primary open-angle glaucoma (POAG).

Main Methods:

• Evaluated 26 eyes of 14 POAG patients and 26 eyes of normal controls using M-ERG.
• Displayed a 103-element hexagonal stimulus matrix on a monitor at a 75-Hz frame rate.
• Compared M-ERG peak-to-trough amplitudes and peak implicit times (N1, P1, N2) with Humphrey static perimetry mean sensitivity values (dB) in corresponding quadrants.

Main Results:

• Significant differences in P1 and N2 peak latencies were observed between POAG and normal groups (P < 0.01).
• No significant differences in M-ERG amplitudes (P1-N1, P1-N2) were found between groups.
• Significant negative correlations were found between implicit times (N1, P1, N2) and visual field sensitivity (r = -0.20 to -0.59, P < 0.05).
• No significant correlations were observed between M-ERG amplitudes and visual field sensitivity.

Conclusions:

• M-ERG peak implicit times, not amplitudes, increase with glaucomatous visual field deterioration.
• M-ERG amplitudes do not appear to decrease with progressive glaucomatous optic nerve dysfunction.