The corneas produced in the laboratory have significantly improved the eyesight of 10 Swedish patients, reports BBC News / Science.
The cornea is a fairly hard, transparent part of the eye through which we look at the world. It covers the pupil and iris. It is made of protein – collagen and refracts light, focusing it on the retina.
Corneal damage is the second most common cause of blindness worldwide – it affects approximately 10 million people. In countries with tissue banks, corneal injuries and diseases are treated with corneal transplantation. However, their supply is insufficient.
The Swedish company Fibrogen made biosynthetic corneas entirely from synthetic collagen, similar to human collagen. Efforts have been made to recreate the properties of the human cornea as well as possible using the DNA sequences of yeast and humans.
The abnormal corneas were removed from the eyes of 10 patients and replaced with synthetic ones. The observation continued for another two years. Sight improved in all patients, six of them from 20/400 to 20/100 – meaning they could see objects 4 times farther away than before the operation.
The experiment was conducted under the supervision of prof. May Griffith from Linkoping University, who was essentially just to confirm the safety of biosynthetic corneas – patients waited for a donor transplant. The improvement in eyesight was an unexpected benefit – artificial corneas turned out to be as good as natural. The new corneas made it easier for patients to regenerate the eye’s nerves and cells – nerve regeneration was even better than with a donor transplant. There were no problems with rejection of the graft, and the cornea was also sensitive to touch.
Until now, plastic corneal prostheses have been used in patients who have failed donor corneal transplants, but these can cause serious side effects, such as glaucoma, infections, and retinal detachment. (PAP)