Age-related macular degeneration (AMD) is one of the most common causes of blindness in the developed world. Although treatments have been developed for ‘wet’ AMD, which is caused by bleeding at the back of the eye, there are currently few treatments for the most common form of AMD, ‘dry’ AMD. Dry AMD results from a slow loss of cells at the macula, the part of the retina responsible for central vision. The immune system is through play crucial part in disease mechanism.
A common feature of dry AMD is subretinal deposits called pseudodrusen. Patients with pseudodrusen suffer from faster disease. Little is known about why pseudodrusen develop and how they worsen degeneration. The study of pseudodrusen and the development of treatments has been limited by a lack of suitable models.
Recently we studied an animal that developed subretinal deposits similar to pseudodrusen. We identified abnormally activated immune cells to play a role in the early formation of these subretinal deposits. To better understand the cause of this subretinal immune cell activation we developed a technique to study individual retinal immune cells, by isolating these cells and then studying which genes each of these cells expressed.
These studies identified a gene activation pathway turning inactive cells to active cells associated with disease. The studies identified therapeutic targets to potentially turn these disease-associated cells off again and so potentially slow rate of macular degeneration.
The next aim is to repurpose FDA approved immunomodulatory drugs that specifically target the ‘bad’ immune cells identified in our studies while sparing the ‘good’ immune cells responsible for immune protection in our model and if successful will aim to translate successful treatments to human clinical trial to treat patients in early AMD with pseudodrusen in order to slow macular degeneration.