Surgeons at Great Ormond Street Hospital (GOSH) have carried out pioneering eye gene therapy treatment for rare form of genetic blindness following 10 years of research.
Researchers developed a way to help children with a severe genetic eye condition called Leber Congenital Amaurosis-4 (LCA4), using a virus to provide the missing DNA to their retina.
LCA4, a rare inherited retinal degeneration, is caused by the deficiency of the AIPL1 gene and results in complete loss of sight.
The gene therapy treatment involves keyhole surgery to inject the missing genes into the retina of the patient. The operation takes around one hour for surgeons to perform and patients are able to leave hospital later the same day wearing an eye patch.
A world-first for this condition
In a world-first for this condition, GOSH surgeon Chien Wong, along with Professor James Bainbridge from Moorfields Eye Hospital, performed the operation on a patient last year.
Mr Wong said: “Researchers from Moorfields and UCL Institute of Ophthalmology, led by Professor Robin Ali, developed the treatment that involves delivering copies of healthy AIPL1 genes to the retina using disabled viruses.
“From a surgical perspective, all four operations went very smoothly. At this early stage, the treatment has some encouraging signs and patients will have longer term follow ups.”
Surgeons have operated on four patients to treat LCA4 to date, with the most recent surgery being carried out on two year old Jace from Connecticut, USA, last month.
Prior to surgery, Jace responded to light but has never been able to track objects or see faces. His parents learnt about the gene therapy surgery at a LCA conference last summer and later had discussions with Mr Wong and Professor Bainbridge to discuss whether he would be suitable for the surgery.
Jace’s parents said:
“The team at GOSH that worked on Jace were incredible. We knew he was in the best hands under their care. Recovery has been going well and once we were able to remove the patch from his eye the morning after surgery, it has not seemed to bother him one bit.
“Our long term hope has been that the surgery helps to slow down the deterioration of his retina so that he can maintain his light perception. In taking part in this surgery and research, we also hope that this helps those studying the disease to learn more about LCA, specifically AIPL1.”
The first surgery of its kind
The first surgery of its kind took place last summer on two-and-a-half-year-old Fatma from Tunisia, who was only able to see light and would eventually lose that ability completely.
Fatma’s parents approached Professor James Bainbridge and Professor Michel Michaelides at Moorfields about the gene therapy treatment, which was developed with the support of Moorfields Eye Charity, Retina UK and the UK National Institute for Health Research.
The team of surgeons who carried out the surgery said they were encouraged by the results from Fatma’s surgery and her parents said they were seeing improvements in their daughter’s responses.
Fatma’s mother said: “She has responded to the light very fast, and she’s responding to it more day by day. We are participating in medical development, and it is a good experience for her and for us too.”
The treatment was provided by MeiraGTx, a clinical-stage gene therapy company, pursuant to a specials license for compassionate use.