Where is the MOST appropriate mirror location for a patient with a unilateral temporal VF defect?

Where is the MOST appropriate mirror location for a patient with a unilateral temporal VF defect?

• A. Temporal portion of affected eye
• B. Nasal portion of affected eye
• C. Temporal portion of non-affected eye
• D. Nasal portion of non-affected eye

Answer: (B)

A unilateral temporal visual field defect maps to the nasal retina of that same eye. So when using a mirror to position stimuli or control where the patient looks during testing, placing the mirror on the nasal side of the affected eye channels the test stimuli to the nasal retina, which is the region responsible for the temporal field in that eye. This arrangement best reveals the defect because you’re targeting the retina that actually corresponds to the impaired portion of the field. Placing the mirror elsewhere would either engage the intact retina/field or the other eye, making the temporal defect harder to detect.

A unilateral temporal visual field defect maps to the nasal retina of that same eye. So when using a mirror to position stimuli or control where the patient looks during testing, placing the mirror on the nasal side of the affected eye channels the test stimuli to the nasal retina, which is the region responsible for the temporal field in that eye. This arrangement best reveals the defect because you’re targeting the retina that actually corresponds to the impaired portion of the field. Placing the mirror elsewhere would either engage the intact retina/field or the other eye, making the temporal defect harder to detect.