Evaluating optogenetic therapy in presence of surviving photoreceptors

Brief plain language background


Retinal degenerative disorders are a group of eye diseases that include age-related macular degeneration (AMD), which most commonly affects older people – as well as rare genetic conditions, such as retinitis pigmentosa (RP), which often begin in childhood.

The retina contains millions of light-sensing cells (photoreceptors), which are vital for healthy eyesight. In people with retinal degenerative disorders, these cells stop working and eventually die – causing progressive sight loss.


What problem/knowledge gap does it help address?

A next-generation treatment strategy – called optogenetics – has the potential to help to reverse sight loss in people with advanced retinal degeneration. It involves using a harmless virus to deliver a gene containing the instructions for a light-sensing protein (called a photopigment) into surviving retinal cells to give them the ability to detect light and restore vision.

So far optogenetic therapy has only be tested in animals and clinical trials in people with complete vision loss. However, many people with retinal degeneration have partial vision loss and still have some surviving photoreceptors.

It is currently unclear whether optogenetic therapy would improve the vision of these people or make it worse. It is also unknown whether optogenetic therapy is safe to use when the retina is more intact.


Aim of the project

To evaluate the function and safety of optogenetic therapy in the retina with surviving photoreceptors.

This project also aims to further the career progression of the applicant, as amongst other benefits, the findings could form the basis of future grant applications examining optogenetic therapy improvement.

Key procedures/objectives

• Test retinal electrical activity in response to visual stimuli under three conditions to isolate activity driven by photoreceptors, optogenetics and a combination of the two.
• Compare the three conditions to determine whether optogenetic therapy disrupts normal photoreceptor activity.

Examine any damage in retinas with surviving photoreceptors caused by optogenetic therapy.

Potential impact on people with sight loss

Understanding how optogenetic therapy works in retinas with surviving photoreceptors could help determine its suitability for people with partial sight loss. Gaining insight into the factors shaping restored visual responses could be utilised to improve optogenetic therapies.