Imagine a darkness, a darkness so vast that you cannot escape, a darkness so black it envelops your life, a darkness so cursed that it does not allow you to see your mother's face. Now imagine a light at the end of this dark void, a light of hope to save you from this damned existence. That light is in the form of genetic therapy that lifts the curse, which plagues your existence, and enables you to finally observe the world around you.
285 million people are estimated to be visually impaired worldwide out of which 39 million are blind and 246 have low vision. About 90% of the world's visually impaired live in low-income settings.
A genetic therapy has come to the forefront which promises to improve the visions of patients who would have otherwise, never witnessed the world around them. The most common form of blindness in young people could at least be partially cured using this technique as positive experiments have already been carried out on mice. Researchers were successful in restoring the sight in mice affected by retinitis pigmentosa after reprogramming their remaining retinal nerve cells. These were not light-sensitive but were altered by the technique to give the mice a degree of vision.
A separate experiment, also conducted on mice, showed that gene editing can also be utilized to halt the progress of glaucoma, an eye disease that is often associated with elevated intraocular pressure, in which the optic nerve is damaged. Glaucoma is the leading cause of irreversible blindness in the world. Genetic mutations can lead to a build-up of toxic proteins in the eye, increasing the pressure inside and leading to glaucoma. The gene editing technique used to stop glaucoma from getting worse in mice is known as “Crispr-Cas9” and knocks down the manifestation of mutant genes, thereby reducing the pressure in the eye and preventing further glaucomatous damage. Scientists claim that the same technique is expected to be effective on humans as well, and if so, it will undoubtedly lead to a drastic improvement in the treatment of glaucoma.
Scientists have also recognized a possible approach to treat end-stage retinal degeneration through a gene therapy which would produce a natural photosensitive protein in the eye, called melanopsin, which is not dependent on the presence of rods or cones to be active and could assist in the restoration of the lost sight in a patient with end-stage retinal degeneration.
Professor Alan Boyd, president of the Faculty of Pharmaceutical Medicine in the UK, said the use of gene therapy to treat blindness had seen “significant success in recent years”. He said a US company, Spark Therapeutics, had already applied for its gene therapy technique to be approved to treat children’s eye diseases in the US and European Union. As the method gains approvals from various authorities, it will not only greatly benefit patients suffering from the aforementioned ailments but the practical application of this procedure will also lead to its improvement which would increase the range of diseases that can be treated using this procedure.
Although such methods have, as of yet, been ineffective on people with advanced blindness, it is definitely a great leap forward in our path to achieve that goal and this discovery will certainly be a gateway towards finding a cure for such patients as well.