In May, an American team, led by plastic surgeon Dr. Eduardo Rodriguez, completed a partial face and whole eye transplant.

The recipient, 46-year-old Aaron James, had suffered horrific injuries while at work, when an electrical cable touched the left side of his face.

Such were his injuries that he was placed in a medically induced coma for six weeks. The incident left him with extensive damage to the left side of his face including left eye, which was removed due to pain. Sadly, he also lost his left arm, his dominant arm.

Dr Rodriquez became aware of Aaron’s case two months after the accident, and from then on with a team of multiple specialists, discussed the possibility of a partial face transplant. The decision to include an eye transplant was partly for cosmetic appearance and also the hope that this donor eye may regain function.

Six months down the line, Aaron is doing well, supported by his wife of twenty years Meagan. He is able to talk and eat food, two of the things we take for granted. Yet in this case, they represent a massive success.

Though Aaron reports no sight as yet in the new eye, all the tests show that the organ is healthy. Its blood supply remains intact and the pressures in the eye have been reported as normal.

While lack of sight may be seen as a crushing defeat, the surgical team are still hopeful of this in time.

Even a year ago, some scientific papers reported that whole eye transplant would unlikely ever be a reality. Others were saying that it may be a possibility within the next 10-20 years.

You may wonder why this is so difficult. After all, eye surgery is a rapidly expanding field. Parts of the eye have been transplanted with great success at restoring vision.

The cornea, the clear part of the eye at the front, is one of the most transplanted organs worldwide.

The success of this is down to several factors. Many are happy to donate their corneas after death. The cornea does not have a blood supply. As a result, corneas can be safely stored in so called banks for much longer than any other organ would survive outside of the body.

The second benefit of not having a blood supply is that the recipient does not recognise the organ as foreign. Hence there is no need for lifelong drugs to prevent the body rejecting it.

The main issue behind the lack of success of whole eye transplants is the optic nerve. Located at the back of the eye, it is approximately 30 mm long and around 5.5 millimetres at its widest point. Despite this, it contains over a million nerve fibres.

Its role is to transmit signals from the retina, the back of the eye, to the brain. These are then processed by a part of the brain called the visual cortex. This converts them into actual images.

Yet when the optic nerve is cut, it dies. For it to recover, it must regenerate in two places, at the back of the eye, and where it is reconnected to the brain.

Though the first reported whole eye transplant was in 1969, a claim that was later disputed, this vital step of the optic nerve working again is the one piece of the puzzle that is holding back eye transplantation from becoming a reality.

Scientists have successfully transplanted whole eyes in mice rats as far back as 2010. They encountered the same issue of the optic nerve dying once cut. However, a gene called BAX was identified. In those animals without the gene, the optic nerve remained healthy, whereas in those with the gene, these nerve cells were dead within three weeks.

Drugs that block this BAX gene may be one of the ways forward.

A second hurdle is getting the optic nerve to regrow. It is not as simple as it regrowing at the point where it is cut, it has to reform all the way from the back of the eye to the brain. Again, the same team turned to a drug used to treat those suffering with multiple sclerosis.

The results were surprising to say the least, with nerves regrowing at the point of being cut within 28 days.

Clearly this is early days, but may be the start of a significant breakthrough.

Sight loss affects nearly 2.2 billion people worldwide. It is a leading cause of disability, not being able to work, and loss of independence. Anything that can address this will be wonderful news.

Dr. Zak Uddin is a GP