Photoreceptor changes in Leber hereditary optic neuropathy with m.G11778A mutation.

Area of Science:

• Ophthalmology
• Neuroscience
• Genetics

Background:

• Leber hereditary optic neuropathy (LHON) is a maternally inherited mitochondrial disease.
• It primarily affects the optic nerve, leading to vision loss.
• Understanding photoreceptor involvement is crucial for LHON management.

Purpose of the Study:

• To assess functional and structural photoreceptor changes in LHON patients and asymptomatic carriers.
• To utilize full-field electroretinography (FERG) and optical coherence tomography (OCT) for evaluation.

Main Methods:

• Cross-sectional observational study including 14 LHON patients, 12 asymptomatic carriers, and 14 controls.
• FERG a-wave amplitudes were analyzed under dark- and light-adapted conditions.
• OCT measured outer nuclear layer (ONL), inner/outer segment (IS/OS), and total photoreceptor thickness.

Main Results:

• Significantly decreased FERG a-wave amplitudes in both LHON patients and carriers (P<0.001).
• Slightly thicker ONL and total photoreceptor layers in patients compared to controls (P<0.05).
• Thinner ONL and total photoreceptor layers in carriers compared to controls (P<0.05).

Conclusions:

• Photoreceptor function is demonstrably impaired in LHON patients and carriers.
• Subtle alterations in photoreceptor morphology, specifically ONL thickness, are present.
• These findings highlight the widespread impact of LHON beyond the optic nerve.