The purpose of this study is to evaluate the safety and tolerability profile of ascending doses of GS010 in Leber Hereditary Optic Neuropathy (LHON) patients.

Inclusion Criteria:

Documented diagnosis of LHON based on a genetic test confirming the presence of the G11778A mutation in the mitochondrial ND4

Age 18 years old or older at the time of study entry (informed consent signature)

Visual acuity ≤ 1/10 of the less functional eye

Exclusion Criteria:

Any known allergy or hypersensibility to one of the product used during the trial

Contraindication to IVT surgery (anaemia Hb <8g/dl, severe cardiovascular disease, severe coagulopathy…)

Disorder of the ocular humors and of the internal retina involving visual disability

Glaucoma

Presence of other pathology whose symptoms or associated treatments might affect the retina or the optic nerve Vascular retinal occlusion

Narrow angle contra-indicating pupillary dilation

Other cause of optic neuropathy (inflammatory conditions or exposure to toxins...)

Patients presenting known mutation of other genes implicated in pathological retinal conditions