Age-related macular degeneration (AMD) is the leading cause of sight loss in Ireland. In fact, almost 100,000 people over the age of 50 are living with AMD.
There are two main forms of this condition which can affect an area in the back of the eye called the macula. This area is responsible for central and detailed coloured vision.
Dry AMD is the most common and mildest form observed in individuals. Wet-AMD, on the other hand, is less common accounting for approximately 10% of AMD patients. In these cases, new and leaky blood vessels grow behind the retina and damage the macula which can then lead to a rapid loss of vision.
If diagnosed early, wet-AMD can be treated with therapeutic agents to stop the growth of new and leaky blood vessels and thereby potentially prevent further damage. Scientists, however, are continuously exploring other therapeutic avenues to treat macular degeneration. One such avenue is stem cell treatment which holds the potential to replace or repair damaged cells at the back of the eye.
The clinical trial which took place in the UK aims to replenish damaged retinal cells by inserting a ‘patch’ of new cells into patients with severe wet-AMD. Retinal pigment epithelium (RPE) cells, which provide critical support and nourishment to our photoreceptor cells, were first generated from embryonic stem cells. This layer of new RPE was then placed on a specially engineered patch so that it could be easily transplanted into the back of the eye, an area known as the sub-retinal space.
Two patients who both had severe form of wet-AMD were treated using the stem cell based patch and were monitored over 12 months. In this recent publication, investigators reported the successful delivery and survival of the patch. Promisingly, both patients also reported improvements in sight as measured by their ability to read letters of a chart (Snellen chart).
Professor Lyndon da Cruz, consultant retinal surgeon at Moorfields Eye Hospital NHS Foundation Trust, said: “The results suggest that this new therapeutic approach is safe and provides good visual outcomes. The patients who received the treatment had very severe AMD, and their improved vision will go some way towards enhancing their quality of life. We recognise that this is a small group of patients, but we hope that what we have learned from this study will benefit many more in the future.”
While this treatment is in the very early stages of its assessment, such findings hail a new era for regenerative medicine. Additional work will be required to fully evaluate the safety, tolerability and efficacy of this treatment among a larger number of patients. Given the promise of these initial findings, further investigation will define the exact benefit this treatment holds for people living with wet-AMD.
The results from this study mark a significant milestone in addressing the currently unmet need in developing treatments for macular degeneration, a condition which can greatly impact a person’s quality of life. Like many others, Fighting Blindness will be following these developments closely and aim to keep you fully informed.
For more information on AMD, please visit https://www.fightingblindness.ie/eye-conditions/age-related-macular-degeneration/ or contact research@fightingblindness.ie.