Electrophysiological and Structural Changes in Chinese Patients with LHON

Area of Science:

• Ophthalmology
• Neuroscience
• Genetics

Background:

• Leber hereditary optic neuropathy (LHON) is a maternally inherited mitochondrial disease causing acute or subacute vision loss.
• Understanding the progressive structural and electrophysiological changes in LHON is crucial for monitoring disease and evaluating treatments.

Purpose of the Study:

• To retrospectively analyze the electrophysiological and structural retinal changes in Chinese patients with genetically confirmed Leber hereditary optic neuropathy (LHON).

Main Methods:

• Retrospective analysis of 26 eyes from 13 Chinese LHON patients, categorized into acute (Group 1, <3 months) and chronic (Group 2, 3 months-18 years) disease duration.
• Evaluations included clinical history, comprehensive visual electrophysiology (Pattern ERG, Multifocal ERG), optical coherence tomography (OCT), and color fundus photography.

Main Results:

• Acute LHON showed optic disc hyperemia and normal retinal nerve fiber layer (RNFL) thickness, while chronic LHON exhibited optic atrophy and reduced RNFL thickness.
• Both acute and chronic stages demonstrated significant thinning of the retinal ganglion cell (GCL) plus inner plexiform layer (IPL) and reduced Pattern ERG (PERG) N95/P50 ratio.
• Multifocal ERG (mfERG) revealed subnormal macular responses in both stages, with increasing severity in chronic LHON.

Conclusions:

• LHON presents distinct retinal structural and functional alterations in acute versus chronic phases.
• Retinal ganglion cell dysfunction and GCL+IPL thinning are present in both stages, with additional peripapillary RNFL loss and more severe RGC dysfunction in the chronic stage.
• Comprehensive electrophysiological and OCT assessments are vital for tracking LHON progression and assessing therapeutic interventions.