[Measurement of retinal nerve fiber layer thickness in Leber hereditary optic neuropathy by optical coherence tomography].

OBJECTIVE: To evaluate retinal nerve fiber layer (RNFL) thickness in patients and unaffected carriers of Leber hereditary optic neuropathy (LHON) by optical coherence tomography (OCT).

METHODS: This case-control study enrolled 42 LHON maternal family members with mitochondrial DNA G11778A mutation and 100 normal volunteers. RNFL thickness was measured by Stratus OCT in each participant. Mean RNFL thickness of each quadrant, as well as 360° average were calculated and compared in normal controls, LHON carries and LHON patients.

RESULTS: Among LHON maternal family members, 15 cases were unaffected carriers who were subgrouped as normal-fundus-appearing carriers (10 cases) and preclinical carriers (5 cases). Twenty seven LHON patients included 9, 5, and 13 cases in the early, advancing and advanced stages, respectively. Normal fundus-appearing carriers showed normal RNFL thickness of each quadrant and 360° average. Preclinical carriers and early-staged patients showed no significant difference in RNFL thickness of each quadrant and 360° average (P = 0.138 to 0.645), yet both showed thicker RNFL in temporal, superior and inferior quadrant, as well as 360° average, if compared with normal controls (P = 0.000 to 0.018). Compared with normal controls, preclinical carriers and early-staged patients, advancing LHON patients showed thinner RNFL in temporal and inferior quadrant, as well as 360° average (P = 0.000 to 0.005). Advanced LHON patients showed thinner RNFL in each quadrant and 360° average, compared with normal controls, LHON carriers, and advancing cases (P = 0.000 to 0.037).

CONCLUSIONS: RNFL thickness in LHON patients and unaffected carriers was characterized by OCT in this study, which would improve the understanding of the natural course of LHON.