Researchers have formulated a new oral medication to be used to treat people with Leber congenital amaurosis (LCA), a form of childhood blindness.
This is quite a breakthrough in the world of medicine as no treatment for the disease was available until now. The new medication will be used to restore vision in patients with LCA.
"This is the first time that an oral drug has improved the visual function of blind patients with LCA," said the study's lead author, Dr. Robert Koenekoop in a press statement. "It is giving hope to many patients who suffer from this devastating retinal degeneration."
The study was conducted on 14 people aged between 6 and 38 years and having LCA. Researchers noted that the cause of their disease was either mutations in the gene RPE65 or LRAT. These mutations led to a serious defect in the retinoid cycle, which is responsible for producing a molecule called 11-cis retinal. This molecule captures light and initiates vision.
"By giving patients with RPE65 or LRAT mutations an oral retinoid intermediate (QLT091001) most patients' vision improved rapidly. We discovered that a certain portion of the retinal cells that were not working because of the lack of 11-cis retinal could be woken up," explained Dr. Koenekoop. "Contrary to what was previously thought, children with LCA and defects in RPE65 or LRAT are not born with dead retinal cells; the cells can simply go dormant, and they can remain dormant for years before they eventually die. The oral drug we tested awakened these cells and allowed patients to see."
Researchers noted that 10 out of the 14 patients experienced an expansion in their visual field while the remaining four experienced improvement in their visual acuteness. Researchers also observed marked improvement in brain activities in all participants. The study authors said that more research need to be conducted to get a better knowledge about the retinal function in blind people in relation to dosage and methodology.
"This revolutionary breakthrough to restore sight in children who are blind shows that investing in vision research over the long-term really can make miracles happen," said Sharon Colle, president and CEO of the Foundation Fighting Blindness, the largest charity funding sight-saving research in Canada.
Leber congenital amaurosis occurs in 2 to 3 per 100,000 new-borns. It is one of the most common causes of blindness in children, according to Genetics Home Reference. It is an inherited retinal degenerative disease characterized by severe loss of vision at birth. A variety of other eye-related abnormalities including roving eye movements, deep-set eyes, and sensitivity to bright light also occur with this disease. Some patients with LCA also experience central nervous system abnormalities.
The most common early symptom is nystagmus (shaking of the eyes), and it is usually evident within the first few months of life. As a child gets older, poor vision/tracking, sensitivity to light and poking/rubbing of the eyes with a fist or finger may be noted. The ophthalmologist may see sluggish reaction of the pupils, need for glasses, and abnormal appearance of the retina. Other less common findings include cataract, glaucoma, and cornea problems, according to a UCSF Medical Center report.
Findings of the study were published online in the scientific journal The Lancet. The research was supported by QLT Inc, the Foundation Fighting Blindness Canada, the Canadian Institutes of Health Research (CIHR), the Fonds de recherche du Québec - Santé (FRQS), Vision Health Research Network of the FRQS and The Montreal Children's Hospital Foundation.
