To evaluate the safety and efficacy of a new therapeutic agent, EPI-743, in Leber hereditary optic neuropathy (LHON) using standard clinical, anatomic, and functional visual outcome measures. Design: Open-label clinical trial. Setting: University medical center. Patients: Five patients with genetically confirmed LHON with acute loss of vision were consecutively enrolled and treated with the experimental therapeutic agent EPI-743 within 90 days of conversion. Intervention: During the course of the study, 5 consecutive patients received EPI-743, by mouth, 3 times daily (100-400 mg per dose). Main Outcome Measures: Treatment effect was assessed by serial measurements of anatomic and functional visual indices over 6 to 18 months, including Snellen visual acuity, retinal nerve fiber layer thickness measured by optical coherence tomography, Humphrey visual fields (mean decibels and area with 1-log unit depression), and color vision. Treatment effect in this clinical proof of principle study was assessed by comparison of the prospective open-label treatment group with historical controls. Results: Of 5 subjects treated with EPI-743, 4 demonstrated arrest of disease progression and reversal of visual loss. Two patients exhibited a total recovery of visual acuity. No drug-related adverse events were recorded. Conclusions: In a small open-label trial, EPI-743 arrested disease progression and reversed vision loss in all but 1 of the 5 consecutively treated patients with LHON. Given the known natural history of acute and rapid progression of LHON resulting in chronic and persistent bilateral blindness, these data suggest that the previously described irreversible priming to retinal ganglion cell loss may be reversed.

Citation: Moura ALA, Nagy BV, La Morgia C, et al. The pupil light reflex in Leber's hereditary optic neuropathy: evidence for preservation of melanopsin-expressing retinal ganglion cells. Invest Ophthalmol Vis Sci. 2013;54:4471-4477. DOI: 10.1167/iovs.12-11137 PURPOSE. To investigate the pupillary light reflex (PLR) of patients with severe loss of vision due to Leber's Hereditary Optic Neuropathy (LHON) in the context of a proposed preservation of melanopsin-expressing retinal ganglion cells (mRGCs). METHODS.Ten LHON patients (7 males; 51.6 6 14.1 years), with visual acuities ranging from 20/400 to hand motion perception and severe visual field losses, were tested and compared with 16 healthy subjects (7 males; 42.15 6 15.4 years) tested as controls. PLR was measured with an eye tracker and the stimuli were controlled with a Ganzfeld system. Pupil responses were measured monocularly, to 1 second of blue (470 nm) and red (640 nm) flashes with 1, 10, 100, and 250 cd/m 2 luminances. The normalized amplitude of peak of the transient PLR and the amplitude of the sustained PLR at 6 seconds after the flash offset were measured. In addition, optical coherence topography (OCT) scans of the peripapillary retinal nerve fiber layer were obtained.RESULTS. The patient's peak PLR responses were on average 15% smaller than controls (P < 0.05), but 5 out of 10 patients had amplitudes within the range of controls. The patients' sustained PLRs were comparable with controls at lower flash intensities, but on average, 27% smaller to the 250 cd/m 2 blue light, although there was considerable overlap with the PLR amplitudes of control. All patients had severe visual field losses and the retinal nerve fiber layer thickness was reduced to a minimum around the optic disc in 8 of the 10 patients.CONCLUSIONS. The PLR is maintained overall in LHON patients despite the severity of optic atrophy. These results are consistent with previous evidence of selective preservation of mRGCs.

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