The application of flash visual evoked potentials during operations on the anterior visual pathways

Area of Science:

• Neuroscience
• Ophthalmology
• Surgical Technology

Background:

• Anterior visual pathway compression poses risks to vision.
• Accurate intraoperative monitoring is crucial for preventing optic nerve damage.

Purpose of the Study:

• To evaluate the utility of flash visual evoked potentials (F-VEP) in patients with anterior visual pathway compression.
• To establish a grading system for abnormal F-VEP findings.
• To assess the correlation between F-VEP changes and clinical visual testing outcomes.

Main Methods:

• F-VEP recordings were obtained from 15 patients (30 eyes) pre-, intra-, and post-operatively.
• A grading system for F-VEP abnormalities was developed using data from 40 patients (80 eyes).
• Clinical visual acuity and visual field tests were performed concurrently.

Main Results:

• No significant correlation was found between F-VEP changes and visual acuity or visual field.
• Intraoperative F-VEPs were sensitive to halothane and surgical manipulation of the optic nerve/chiasm.
• A grading system for F-VEP abnormalities was established.

Conclusions:

• F-VEP monitoring is valuable for identifying the optic pathway during surgery.
• The technique may help prevent optic nerve damage, particularly with the transsphenoidal approach.
• While not directly correlating with visual acuity, intraoperative F-VEP provides critical pathway information.