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Plant cells restore man's sight - 7th June 2021

Restoring sight to a completely blind man has been achieved thanks to specialised plant cells originally from algae. The innovative therapy, optogenetics, utilises photo-sensitive proteins within the microorganisms to control retina cells in a human eye.

Realising the therapy was taking effect on discovering that he could identify the stripes on a pedestrian crossing, the individual, whose identity has been protected, is currently able to distinguish objects enough to count and identify them when positioned at arm's length.

The man, from Brittany in France, received the life-changing therapy in the capital, having been living with retinitis pigmentosa for the past 40 years – one among more than two million people afflicted with the degenerative disease. The illness leads to the deterioration of light-sensing cells in the retina and whilst it’s more typical for sufferers to retain some degree of vision, this individual had been entirely without sight for 20 years.

In this case, the power of optogenetics was harnessed to regain the ability to perceive light in just one of the man's eyes, through specialists exploiting the characteristics of algae proteins which move in the presence of light. Although used in neuroscience for many years, as a treatment for blindness, this optogenetics experiment is trailblazing.

The nature of the treatment left the man impatient, waiting to see whether it would take effect. Fortunately, while out walking, he experienced his 'Eureka moment' when, out of the blue, the distinctive pattern of a zebra crossing came into view.

Dr José-Alain Sahel of the Paris-based Institute of Vision explained: "This patient initially was a bit frustrated because it took a long time between the injection and the time he started to see something". He continued, "but when he started to report spontaneously he was able to see the white stripes... you can imagine he was very excited. We were all excited."

Despite the fact that this landmark treatment may only ever succeed in partially restoring the man's vision, the accomplishment of providing even limited sight offers a ray of hope to those living with total blindness.