Wet macular degeneration (nAMD), or yellow eye disease, is a retinal disease in which abnormal vascular growth develops in the area of the retina responsible for sharp vision. Wet macular degeneration is a disease of the ageing population and typically affects both eyes over time. Without treatment, patients can gradually lose their ability to read, recognise faces and objects, and their quality of life can deteriorate significantly and rapidly. For almost two decades, the most effective treatment for nAMD has been vascular endothelial growth factor inhibitor therapy (anti-VEGF therapy), which very often involves the injection of various drugs through keyhole surgery.
- The results of conventional treatments are good as long as they are closely controlled and tested in clinical trials. However, once treatment protocols are relaxed, in real-life conditions it is common for treatments to be delayed or less frequent than necessary, and so visual acuity may start to decline. The treatment lasts a lifetime, and the constant checks are stressful," Attila Vajas, clinical chief physician at the Eye Clinic of the University of Debrecen Clinical Centre, told hirek.unideb.hu.
Attila Vajas added that innovative gene therapy is a new approach to long-term treatment of the disease. The University of Debrecen Eye Clinic was the first in Hungary to perform this gene therapy intervention.
- The sophisticated surgical procedure involves the introduction of a viral vector (AAV8 type) into certain layers of the retina. The outer envelope of the vector retains the ability to enter certain cells, along with the genetic map it carries. The vector carries the desired genetic code, which is activated in the target cells. The protein it produces is an inhibitory molecule (anti-VEGF protein fragment), which is very similar to what is injected into the eye during conventional therapies," said Attila Vajas.
(Figure legend: the picture shows the implantation process. The two small bladder-like formations at the top of the picture contain the virus vector with the genetic code it carries.)
The new therapy could not only be a breakthrough in preserving sight, but could also significantly improve patients' quality of life, reducing the need for ongoing treatments.
- Following gene therapy, the level of inhibitory molecules produced inside the eye is almost constant, eliminating the visual impairment caused by irregular treatments. The evidence so far suggests that traditional therapies - external injection - are no longer needed or are rarely needed. Results from an earlier, similar study show that in both eyes, seventy-eight per cent of patients remained injection-free for nine months after gene therapy, with the remainder requiring at most one conventional treatment. Visual acuity was stable throughout," said Attila Vajas.
(Figure legend: the horizontal lines in the figure represent a single patient, and the coloured circles represent the different conventional treatments that patients have received. The vertical line represents the day of the gene therapy treatment. The extreme reduction in the need for conventional treatments is clearly visible).
The Chief Clinical Officer of the Eye Clinic of the University of Debrecen Clinical Centre stressed that gene therapy is currently in the clinical trial phase and is not yet part of daily medical practice, but if the results remain promising, it could revolutionise the treatment of wet macular degeneration and other serious eye diseases.
Press Centre - CzA