Optic disc excavation in the atrophic stage of Leber's hereditary optic neuropathy: comparison with normal tension glaucoma

Background: Abnormal optic disc excavations are reportedly seen in patients with Leber's hereditary optic neuropathy (LHON), a mitochondrial dysfunction disease. We examined the disc morphology in the eyes of patients with LHON at the atrophic stage and compared it to that in eyes with normal-tension glaucoma (NTG). Methods: We studied 15 LHON patients with the 11778 mutation, 15 patients with NTG, and 25 normal subjects. The optic disc morphology was analyzed by Heidelberg retinal tomography (HRT). Ten parameters of the optic disc obtained by HRT were evaluated, including the diagnostic classification of glaucoma. Results: Six of the nine morphological HRT parameters of the LHON patients, the exceptions being disc area, mean cup depth, and maximum cup depth, differed significantly from those of the normals. NTG patients had a significantly greater mean and maximum cup depth than LHON patients. The HRT glaucoma diagnostic software classified 22 (73%) of the 30 optic discs in LHON patients as glaucomatous. Conclusion: The optic discs at the atrophic stage of LHON eyes have glaucoma-like morphological changes. However, the cups were significantly deeper in NTG than LHON. The similarity in the optic disc findings in LHON and NTG suggests that alterations in mitochondrial function may be related to optic disc excavations.