Retinal Sublayer Thickness Analysis of The Macula of Symptomatic and Asymptomatic Carriers of G11778A Mutations with Leber's Hereditary Optic Neuropathy

Abstract

Background Leber's hereditary optic neuropathy (LHON) is a maternally inherited mitochondrial genetic disease, caused mainly by G11778A mutations. Analysis of retinal sublayer structure by spectral domain optical coherence tomography(SD-OCT) is of great significance for elucidating the pathogenesis of LHON. Purpose To analyze the thicknesses of the outer plexiform layer (OPL), outer nuclear layer (ONL), photoreceptor inner and outer segment (IS/OS), and macula thickness (MT) in symptomatic and asymptomatic carriers of G11778A mutants with LHON using SD-OCT. Methods In this cross-sectional study, a total of 70 symptomatic carriers with the G11778A mutation were enrolled in Renmin Hospital of Wuhan University. Family members of symptomatic carriers were recruited as asymptomatic carriers for a final total of 36 participants. We also recruited 29 age- and sex-matched normal subjects. Results MT of symptomatic carriers was thinner than for asymptomatic carriers, while asymptomatic carriers were thinner than normal subjects. In carriers of the G11778A mutation, OPL thickness was increased, and ONL thickness was decreased compared to normal cases. Correlation analysis showed that MT was significantly correlated with peripapillary retinal nerve fiber layer (pRNFL) and disease duration, while ONL thickness in parafoveal nasal areas thinned as the disease progressed. The three groups showed no significant differences in IS/OS thicknesses. Conclusions The thicknesses of OPL, ONL and MT differed between normal subjects and symptomatic and asymptomatic carriers of G11778A mutations with LHON. MT and ONL thinning, in addition to OPL thickening, were observed in symptomatic and asymptomatic carriers, a finding which should be further validated and explored in basic science research. Additional longitudinal studies are needed to determine the usefulness of these findings to the diagnosis and monitoring of LHON.