Assessing Early Stage Open-Angle Glaucoma in Patients by Isolated-Check Visual Evoked Potential

Area of Science:

• Ophthalmology
• Neuroscience
• Medical Imaging

Background:

• Glaucoma, a leading cause of blindness, damages the optic nerve and can be detected earlier using visual evoked potential (VEP) techniques.
• The magnocellular ON pathway, crucial for early glaucoma detection, is targeted by specific visual stimuli.
• Standard operative procedures (SOP) are essential for reliable electrophysiological measurements in glaucoma diagnosis.

Purpose of the Study:

• To evaluate the efficacy of isolated-check visual evoked potential (icVEP) for early detection of open-angle glaucoma (OAG).
• To establish a reliable SOP for icVEP testing to ensure accurate diagnostic results.
• To correlate icVEP findings with retinal nerve fiber layer (RNFL) thickness in early OAG patients.

Main Methods:

• Utilized a 10 Hz, 15% positive-contrast bright stimulus in an icVEP protocol with standardized procedures.
• Recorded cortical activity and analyzed signal-to-noise ratios (SNR) using automated software and multivariate statistics.
• Employed receiver-operating-characteristic (ROC) curves to assess the classification accuracy of icVEP for OAG detection.

Main Results:

• icVEP successfully detected visual function abnormalities in the central visual field, indicated by an abnormal SNR (≤ 1).
• The derived SNR values demonstrated a correlation with RNFL thinning in early-stage OAG.
• The icVEP method achieved high classification accuracy in differentiating OAG patients from control subjects.

Conclusions:

• The standardized icVEP technique is a valuable and objective tool for the early diagnosis of glaucoma.
• icVEP can identify glaucomatous visual field defects and RNFL thinning, crucial for timely intervention.
• This electrophysiological method offers a faster and earlier detection of glaucoma compared to traditional methods.