Understanding how immune cells cause scarring in wet age-related macular degeneration (Added 11/07/19 )
31 May 2019
Source: Fight for Sight
A study funded by research charity Fight for Sight aims to understand the role that our own immune cells play in the development of macular scarring. This scarring can cause irreversible sight loss in more than half of patients with the wet form of age-related macular degeneration (wet AMD), the leading cause of sight loss in the UK.
Image of macular scar
The knowledge gained by Queen’s University Belfast researchers, whose funding was announced today by the charity, will be used to develop new therapies that target immune cells to prevent and treat retinal scarring.
Wet AMD results in the loss of sight due to the growth of abnormal blood vessels in the central part (macula) of the back of the eye (retina).
Current treatments work by destroying the abnormal blood vessels that develop in the eye, but unfortunately half of patients are unable to benefit from this treatment due to the development of scar tissue in the macula, which severely reduces the effectiveness of treatment.
It is not fully understood why scarring occurs and there are no treatments available to prevent or treat it. Researchers aim to develop new treatments based on the knowledge gained from this project.
Dr Neil Ebenezer, Director of Research, Policy and Innovation at Fight for Sight, said: “Macular degeneration is the most common cause of severe sight loss in older adults and it can have a huge impact on people’s lives. By understanding the mechanisms behind scarring it will not only allow current treatments to work to its full capacity, but it will also help aid the development of new therapies for patients living with this condition”.
Lead researcher, Professor Heping Xu from Queen’s University Belfast, said: “Macular scar, once formed, can cause permanent damage to vision. The abnormal vessels in wet AMD take months to years to scar, which offers a window for prevention or early treatment. We have been investigating the mechanism underlying scar development from abnormal vessels for more than five years. Our goals are to improve current therapy and to develop strategies for scar prevention or treatment. The funding from Fight for Sight will greatly help us to achieve the goals.”
Inflammation is known to play an important role in the wound-healing scarring response to tissue damage. When tissue is damaged, immune cells such as macrophages, are recruited to remove debris and promote repair. Researchers believe that the excessive recruitment and accumulation of macrophages contributes to the development of scarring.
Microscopic investigations will be carried out on donated eyes from wet AMD patients. The macrophages will be labelled with different markers and examined using an imaging technique. Macrophages involved in promoting scarring will be identified alongside the macrophages which dissolve macular scarring. The underlying mechanisms behind the recruitment of pro-scarring macrophages will be examined and explored.
Age-related macular degeneration is the most common cause of severe sight loss in older adults. There are over 600,000 people in the UK with sight loss caused by the two types of macular degeneration (wet and dry) and this number will more than double by 2050.