Degenerative diseases of photoreceptors in eyes are a leading cause of blindness. They can either be inherited like Retinitis Pigmentosa (RP) or are due to age related factors. Whatever the cause, there is currently no cure available, but Dr. Kramer and his research team at University of California have uncovered a chemical named as DENAQ which they have shown to be effective in restoring sight. But before knowing how that works, being aware of how retina makes us see everything is important.
Retina is the light sensitive layer of tissues where image is formed. When exposed to light, the retinal nerve cells undergo chemical and electrical changes, conveying those signals to different visual centres of the brain which responds to signals forming an image on the retina. There are two main types of photoreceptor cells present on retina – rods which differentiate between black and white vision and cones which provide the perception of colors. But out of the three layers of retina, these photoreceptors are present only on the outer layer.
When a degenerative disease occurs the rod and cones start to die thus causing blindness, but it causes no harm to the rest of the retina. The inner retinal layers and their nerve endings remain connected to the brain, but as no vision is perceived by the outer layer they can no longer transmit any visual information to the brain.
Now what this chemical ‘DENAQ’ does is that it turns those light insensitive layers of cells into the light sensitive ones and the most amazing thing is that it only impacts the inner layers of cell if the outer layer containing rods and cones is damaged, that is – it does not have any effects on healthy retina.
It seems as if the degeneration of photoreceptors causes such electrophysiological effects on the inner layers that enables DENAQ to make those layers photosensitive. While has no effects on healthy retina. This ‘photoswitch’ invented by Dr.Kramer and his researcher has immense advantages as compared to previously invented photo switch which only responded to ultraviolet light, whereas DENAQ responses well to daylight, along with other advantages.
Only one injection into the eye will ensure vision for days. It has almost all the properties scientists have always desired to be in a vision restoring drug. But According to Dr. Kramer, more experimentation is needed to testify its validity and effectiveness. It might take a few years, but once enough evidence shows its safe, it will become the first ever means to cure blindness.
[Source: Cell Press]