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

To evaluate the functional and structural changes of photoreceptors in patients and asymptomatic carriers with Leber hereditary optic neuropathy (LHON) using full-field electroretinography (FERG) and optical coherence tomography (OCT).

Individuals diagnosed with LHON at the Renmin Hospital of Wuhan University and their family members were included in this cross-sectional observational study. The FERG a-wave amplitude of affected patients and asymptomatic carriers was analyzed. The thickness of the outer nuclear layer (ONL), inner and outer segment (IS/OS) and total photoreceptors in the macular fovea and parafovea were measured.

This study included 14 LHON patients (mean age: 20.00±9.37y), 12 asymptomatic carriers (mean age: 39.83±6.48y), and 14 normal subjects (mean age: 24.20±1.52y). The FERG results showed that the dark-adapted 3.0 electroretinography and light-adapted 3.0 electroretinography a-wave amplitudes of patients and carriers were significantly decreased (P<0.001). The ONL and photoreceptors layers were slightly thicker in patients than in normal subjects (P<0.05), whereas they were thinner in carriers (P<0.05). There were no differences in IS/OS thickness among the groups (P>0.05).

Photoreceptors function is significantly impaired in LHON-affected patients and asymptomatic carriers. Meanwhile, photoreceptors morphology is slightly altered, mainly manifesting as a change in ONL thickness.