Scientists have revealed that a new oral medication is showing significant progress in restoring vision to patients with Leber congenital amaurosis (LCA).

According to scientists of Research Institute of the McGill University Health Centre (RI-MUHC), this is the first time that an oral drug has improved the visual function of blind patients with LCA, which causes visual impairment ranging from reduced vision to complete blindness, has remained untreatable.

Robert Koenekoop, director of McGill Ocular Genetics Laboratory at The Montreal Children's Hospital of the MUHC, said that this treatment is giving hope to many patients who suffer from this devastating retinal degeneration.

The study involved 14 participants from around the world with LCA ranging in age from 6 to 38 years old. Their blindness was caused by either mutations in the genes RPE65 or LRAT, leading to a serious defect in the retinoid cycle. The retinoid cycle is one of the most important cycles in the human retina because it produces a molecule called 11-cis retinal which has the special capacity to capture light and initiate vision. Patients with RPE65 or LRAT mutations cannot produce this crucial molecule thus the retinal cells cannot create vision, and slowly die.

The study found that 10out of the 14 patients expanded their visual fields; others improved their visual acuity. The research team performed special brain scans of the visual cortex, which showed marked improvements in brain activities in patients who also improved in field size and acuity.

The study was published in the scientific journal The Lancet.