Treatment of one eye affects both

Sci. Transl. Med. 12, eaaz7423 (2020)

The injection of a gene-therapy treatment for Leber hereditary optic neuropathy (LHON) into only the right eye of patients with LHON resulted in the unexpected improvement of sight in both eyes.

LHON is a monogenic hereditary mitochondrial DNA neuropathy that results in bilateral vision loss for which there is limited treatment. However, gene-therapy strategies are being developed in which the therapeutic protein product is translocated into the mitochondria through a mitochondrial targeting sequence.

Sahel and colleagues carried out a randomized double-masked, sham-controlled phase 3 trial of one such therapy (AAV2/2-ND4) in 37 patients with LHON. For those who were given the treatment, the authors injected the therapy into the right eye only and treated the left with a sham therapy. They found that this therapy induced an improvement in a least one eye in 25 participants and that 29 participants had improvement in both eyes. This was surprising; however, the authors found a plausible mechanistic explanation in a further nonhuman primate study.

Author information



Corresponding author

Correspondence to Hannah Stower.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Stower, H. Treatment of one eye affects both. Nat Med 27, 21 (2021).

Download citation


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing