Abstract
Purpose :
Idebenone has been welcomed as the first clinically available treatment for visual loss secondary to Leber hereditary optic neuropathy (LHON). However, previously published clinical data only focused on the efficacy in patients within the first years from disease onset. The amount of the visual benefit compared with the natural history of the disease is still a matter of debate and it is uncertain whether this treatment has any beneficial effect in LHON once optic atrophy has established. Idebenone is a potent scavenger of free radicals and has also been shown to promote the efficiency of the mitochondrial respiratory chain. Both mechanisms could contribute to a restoration of biochemical function in remaining dysfunctional retinal ganglion cells of eyes with chronic LHON. In the present study, we evaluated the effects of idebenone treatment on visual acuity in patients with chronic LHON.
Methods :
Clinical data of ten consecutive patients with genetically confirmed chronic LHON were analyzed retrospectively. In all of the patients treatment with a daily oral dose of 900 mg idebenone was initiated after more than one year from disease onset of the second eye. Visual acuity was tested every three months during the first year of treatment using illuminated logarithmic reading charts.
Results :
Average time from LHON onset was 10 ± 11 years. Five patients had a disease duration of less than 5 years before treatment and five patients were treated 5 to 34 years after disease onset. At baseline, visual acuity was 0.85 ± 0.43 logMAR with a range of 0.20 to 1.66. During one year of idebenone treatment visual acuity increased clinically and statistically significant in all LHON patients by a mean of 2.5 ± 1.0 lines (p < 0.0001). This effect was not different between both subgroups treated before or after 5 years from disease onset (-0.26 ± 0.12 vs. -0.23 ± 0.08 logMAR, p = 0.50).
Conclusions :
The similar effect of idebenone in both subgroups of chronic LHON patients may most likely not be attributed to a spontaneous recovery. We hypothesize that the observed treatment response was the result of a reactivation of dysfunctional retinal ganglion cells in the chronic disease state. The efficacy of idebenone in long-lasting LHON should be further investigated by clinical studies.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.