Abstract
Purpose: :
Natural history of Dominant Optic Atrophy (DOA) is a relentless and slowly progressive visual loss with no evidence of spontaneous recovery of visual acuity. We recently documented that OPA1 mutations associated with DOA induce defective ATP synthesis when driven by complex I substrates. Furthermore, studies on a Drosophila model with mutant OPA1 showed an increased production of reactive oxygen species and a partial rescue of the clinical phenotype by treatment with antioxidants. Based on these data, we aimed to evaluate the possible benefits of treating DOA patients with Idebenone, a coenzyme Q analogue with antioxidant properties recently proposed as therapy for Friedreich ataxia and Leber’s hereditary optic neuropathy.
Methods: :
Seven consecutive DOA patients with heterozygous mutation in the OPA1 gene were treated with Idebenone (540-675mg/die). All patients underwent a complete ophthalmological examination (including visual acuity measurement, visual field test, and retinal nerve fiber layer thickness measurement by spectral-domain optical coherence tomography) at baseline and one year after the therapy was started.
Results: :
Five patients out of the seven treated reported bilateral subjective improvement in visual function. Visual acuity was improved bilaterally in four of the five patients (mean value OD: from 0.24 ±0.09 to 0.39 ±0.18 OS: from 0.24 ±0.17 to 0.34 ±0.20) but was unchanged in the last case. In the remaining two patients neither subjective nor objective visual improvement was observed (mean visual acuity OO: 0.05±0.0). Mean RNFL thickness did not change from baseline (64.2 ±4.5 µ) to last examination (63.3 ±6.0 µ).
Conclusions: :
This is the first report of improvement in visual function of DOA patients after Idebenone treatment. Patients with better baseline visual acuity were more likely to achieve visual improvement with therapy. This pilot study urges a controlled study to validate the effectiveness of Idebenone therapy in DOA, thus providing for the first time a therapeutic options for these patients.
Keywords: neuro-ophthalmology: optic nerve • mitochondria • neuroprotection