Visual Field Test With Gaze Check Tasks: Application in a Homonymous Hemianopic Patient Unaware of the Visual Defects

Area of Science:

• Neuroscience
• Ophthalmology
• Visual Psychophysics

Background:

• Accurate gaze control is crucial for precise visual stimulus presentation.
• Hemianopia, a visual field defect, can significantly impact daily functioning.
• Existing visual field tests may not always reveal subtle or compensated deficits.

Purpose of the Study:

• To develop and evaluate a novel visual field test incorporating gaze check tasks.
• To investigate the efficacy of this test in detecting hemianopia, particularly in cases of compensation.
• To understand the role of spontaneous eye movements in compensating for visual field defects.

Main Methods:

• Development of a visual field test requiring participants to report stimuli at a fixation point.
• Inclusion of 'gaze check' trials without visual stimuli to ensure fixation accuracy.
• Evaluation of the test in four control participants and one patient with homonymous hemianopia.

Main Results:

• The patient with homonymous hemianopia exhibited significant visual field defects when gaze check tasks were included.
• These defects were not apparent when gaze check tasks were omitted.
• The patient demonstrated compensatory spontaneous gaze movements during testing without gaze checks.

Conclusions:

• The visual field test with gaze check tasks is a valuable tool for detecting hemianopia.
• It effectively identifies visual field deficits that may be masked by compensatory eye movements in daily life.
• Spontaneous, coordinated eye movements can compensate for visual field impairments.