The pattern electroretinogram in glaucoma patients with confirmed visual field deficits.

Area of Science:

• Ophthalmology
• Neuroscience
• Medical Imaging

Background:

• Glaucoma is a leading cause of irreversible blindness.
• Early detection of glaucoma is crucial for preserving vision.
• Pattern electroretinogram (PERG) and static automated perimetry are used to assess visual function.

Purpose of the Study:

• To investigate the correlation between pattern electroretinogram (PERG) amplitude and visual field loss in glaucoma patients.
• To determine if PERG can detect early glaucomatous damage before it is evident on visual field testing.

Main Methods:

• Transient PERGs were recorded in patients with glaucomatous damage and healthy controls.
• Glaucomatous damage was confirmed by disc appearance, Humphrey visual field results, and multifocal visual evoked potentials.
• PERG measures included N95 amplitude and the N95/P50 amplitude ratio.

Main Results:

• A significant proportion of eyes with confirmed glaucomatous damage exhibited normal PERG results.
• PERG amplitude showed a nonlinear relationship with visual field sensitivity, with small field losses causing disproportionately large PERG amplitude reductions.
• PERG amplitudes were similar between both eyes of a patient, even with differing visual field damage levels.

Conclusions:

• PERG may detect very early glaucomatous damage, potentially preceding visual field deficits.
• The presence of normal PERG results in some patients with established glaucoma highlights the complexity of PERG in glaucoma assessment.
• Further research is needed to fully understand the diagnostic utility of PERG in glaucoma.