Visual Functions in Patients With Leber Hereditary Optic Neuropathy

Area of Science:

• Ophthalmology
• Neuroscience
• Visual Science

Background:

• Traditional Leber hereditary optic neuropathy (LHON) visual function data relies on patient self-reports.
• This study objectively evaluates the impact of LHON on visual processing through performance-based tests.

Purpose of the Study:

• To assess the specific deficits in facial recognition and purposeful action execution in individuals with LHON.
• To compare visual task performance between LHON patients and age-matched controls.

Main Methods:

• Twelve LHON patients with central scotoma (5°-20°) and 12 controls performed facial recognition (sex/expression) and object manipulation tasks.
• Facial recognition involved viewing images of increasing size; object manipulation included recording eye movements during interaction with real objects.

Main Results:

• LHON patients demonstrated impaired facial expression recognition, though sex recognition was possible at a 1-m simulated distance.
• Task execution was slower in LHON patients compared to controls.
• Patients exhibited a dynamic visual sampling strategy, evidenced by longer scanpaths and increased saccades/fixations.

Conclusions:

• Facial perception, particularly expression recognition, is significantly compromised in LHON.
• Despite slowed performance, LHON patients can effectively utilize peripheral vision for purposeful object manipulation.