Can boosting natural repair processes help treat sight loss?

Scientists at Queen’s University Belfast are studying the role of damage to tiny blood vessels at the back of the eye in a type of age-related macular degeneration (AMD). They hope to discover new ways of boosting the capacity for these vessels to repair themselves – and so, prevent or slow down sight loss for patients.

The research, led by Professor Alan Stitt, Dr Reinhold Medina and Dr Imre Lengyel at Queens University Belfast, was announced by Fight for Sight in June 2019.

Age-related macular degeneration is the leading cause of blindness in the UK. An estimated 600,000 people are currently living with the condition, and this number is set to more than double to 1.3 million by 2050.

People with the early stages will usually have few symptoms – but those with later stages will experience severe sight loss that hugely affects their quality of life.

There are two types of late-stage. One is called ‘wet’ age-related macular degeneration, where abnormal blood vessels start to grow underneath the retina – there are injections available that can reverse this. The other form is called ‘dry' age-related macular degeneration, where there is a gradual breakdown of light-sensing cells and supporting tissues within regions of the retina.

Unfortunately, there are no effective treatments that can slow down or prevent early stages of the condition from progressing to later stage blinding disease – and there is no current treatment for dry age-related macular degeneration, which accounts for ninety percent of cases.

A priority is to develop effective new treatments that can stop the condition from progressing from early to later stages. But we first need to develop a better understanding of the biology behind different forms of the condition.

The team is investigating the role of a network of fine blood vessels that underlie the retina in the development of the most common late-stage form of the disease. These capillaries supply the outer layer of the retina with vital oxygen and nutrients and are gradually lost in patients, which happens alongside the loss of light-sensing cells and supporting tissues. But how and why this occurs is currently not fully understood.

The researchers have recently discovered that problems with the mechanisms that repair damage to these tiny blood vessels as we age may contribute to the development of this form of age-related macular degeneration – and so they are now investigating this in more detail.

Excitingly, they are already exploring the potential of drugs that can boost the capacity of blood vessels to repair themselves as a way of treating the condition. Some of these are already being tested in clinical trials for other conditions such as stroke. So this research could lead to an entirely new treatment approach to prevent or slow down sight loss in patients.

Patients with a dry age-related macular degeneration could benefit from exciting new treatments that repair damage to eye blood vessels, preventing their disease from progressing to later stages – helping to preserve their sight.