Idebenone Treatment In Leber 's Hereditary Optic Neuropathy

Abstract

Purpose: : To report a retrospective evaluation on the efficacy of Idebenone in a large series of patients with Leber's hereditary optic neuropathy (LHON). LHON is a blinding disorder due to mtDNA point mutations affecting complex I, for which is currently not available a treatment. Based on anecdotal reports and a recently concluded placebo-controlled clinical trial, Idebenone is proposed as a possible therapy for LHON.

Methods: : We reviewed 103 LHON patients, as defined by one of the primary mutation (positions 11778/ND4, 3460/ND1 and 14484/ND6). Forty-four patients underwent Idebenone treatment within one year from the onset of the second eye (early treatment-ET), and the further 59 were untreated (NT). This latter group was used to establish the rate of spontaneous recovery of visual acuity, as defined by the gain of at least two lines. Idebenone dosage ranged between 270 up to 675 mg/die. Frequency of visual recovery was evaluated by chi-square test (p < 0.05) and correlations by Spearman coefficient.

Results: : As a whole there was a non-significant increase in the rate of recovery in ET-patients (45.5%) as compared to spontaneous visual recovery in the NT-group (32.2%). In this latter group patients recovering vision had a significant younger age of onset (p=0.016). Stratifying our cohort by mutation, the rate of recovery in visual acuity was significantly higher in ET-LHON/11778 (47%) compared to NT-LHON/11778 (23%) (p=0.036). For the 11778/ND4 patients who started the treatment in-between-eyes (five patients), the involvement of the second eye was significantly delayed compared to patients treated after the involvement of the second eye (p=0,02). Concerning the remaining mutations, 3460/ND1 and 14484/ND6, the number of patients available was too low to run meaningful statistical analysis. However, the 14484/ND6 patients had a high rate of visual recovery (67% in ET and 83% in NT), whereas the 3460/ND1 patients had 25% rate of recovery in the ET group and 40% in the NT group.

Conclusions: : Despite being a retrospective study, this is the most extensive cohort of LHON patients treated with Idebenone for at least one year, and the subgroup of 11778/ND4 ET-patients had the highest rate of remissions ever reported. Our data support that the use of Idebenone in the acute phase of LHON increases the rate of subsequent visual recovery in the 11778/ND4 subgroup.

Keywords: neuro-ophthalmology: optic nerve • mitochondria • neuroprotection