- Scientists studied the use of synthetic retinoids as a cure for congenital blindness due to LCA.
- LCA is an eye disorder that causes visual impairment since birth.
- Research confirmed that using synthetic retinoids in adults improved vision perception in the brain drastically.
In a brilliant breakthrough in the field of ophthalmology scientists working in collaboration with the University of California, Irvine School of Biological Sciences, and the School of Medicine have found a cure for adult blindness.
The discovery came through while studying congenital or childhood blindness, particularly a condition known as Leber’s Congenital Amaurosis(LCA).
Scientists attempted to apply the cure found for the congenital anomaly in adults with blindness and were successful in restoring vision.
What is LCA?
Leber’s Congenital Amaurosis(LCA) is an eye disorder that is present in infants from birth. This condition is a rare congenital anomaly that primarily affects the retina.
The retina is a highly specialized tissue located at the back of the eye that detects light and color via rods and cones respectively. The rods and cones are photoreceptor cells that relay information via the optic nerve to the visual cortex of the brain and help in vision as we know it.
People with LCA typically have severe visual impairment beginning at birth or shortly afterward. The visual impairment tends to be severe and may worsen over time.
LCA is also associated with other vision problems, including increased sensitivity to light (photophobia), involuntary movements of the eyes (nystagmus), and extreme farsightedness (hyperopia).
At least 20 genetic types of Leber congenital amaurosis have been described. The types are distinguished by their genetic cause, patterns of vision loss, and related eye abnormalities.
Cure for LCA via Retinoid Therapy
Previously the only available route for treating LCA was through gene therapy. Scientists have identified multiple genetic mutations that can cause LCA. Using this information, Gene therapy was used for addressing two mutations in a gene called RPE65, which accounts for about six percent of LCA cases.
Now scientists have discovered that using synthetic retinoids might also cure LCA in children. They worked with rat models to verify their hypothesis.
Research confirmed that using oral QLT091001 a synthetic 9-cis-retinyl acetate in patients with LCA due to mutations in RPE65 and LRAT genes proved fruitful. Such synthetic retinoid supplements aimed to assess the replacement of the missing chromophore 11-cis retinal in these patients.
Synthetic retinoid therapy for adult blindness
The scientists decided to take a shot in the dark to see if such potent synthetic retinoids could prove to be helpful even for adults with acquired blindness. The results were overwhelming.
The corresponding author of the study Professor Sunil Gandhi in UCI confirmed that vision improved in such adults who were placed under trial. The central visual pathway signalling was significantly restored in adults, especially the circuits that deal with information coming from both eyes.
Furthermore, the signals from the opposite-side eye activated two times more neurons in the brain immediately after the treatment. Also, signals coming from the same-side eye pathway activated five-fold neurons in the brain after the treatment.
Dr Gandhi noted that the restoration of visual function at the level of the brain is greater than expected from the improvements previously observed at the level of the retina.
The findings that the treatment works well in the central visual pathway support a new concept that there is latent potential for the vision that is just waiting to be triggered and will certainly broaden the scope of research conducted in this area.
