Sight is probably the sense most of us are scared of losing. But Sahra Abdallah Haji from the Malta Medical Students Association sees the bright side as she focuses on eye transplants and the positive aspect of donating eyes for research or as organ donors.
Sight is one of the five senses that allow us to take in and respond to the environment around us and is probably the sense most people are scared of losing.
Loss of eyesight can be due to trauma, infection, glaucoma, keratoconus (thin, deformed cornea), retinoblastoma (eye cancer) and inherited corneal conditions known as dystrophies, which all lead to severely reduced eyesight, and eventually, some conditions lead to complete blindness.
Some of these conditions even require the removal of the eyeball itself! The idea of such a procedure is likely to instil fear and dread at the thought of never being able to see those that matter the most, never being able to read a book and never seeing where we are going. However, imagine there was something that could be done to fix this. One possible solution is receiving an eye transplant.
Only specific parts of the eye can be transplanted from a dead donor. Donations of whole eyes are usually to an eye bank and can be used for both scientific research as well as transplants. These donated eyes can be used to research whether other parts of the eye can be transplanted and to develop eyesight-improving technologies by carefully studying how individual parts of the eye work together.
Although it is more common to transplant the cornea and the sclera (white of the eye) into recipients, eye lids and tear ducts can also be transplanted as part of full-face transplants.
The cornea is the transparent part of the eye and is made up of six layers. It allows us to focus on objects by converging together all the light that enters the eye from different directions.
A cornea transplant is known as a keratoplasty and about 40,000 are performed in the US annually, according to the Eye Bank Association of America. This operation involves an eye surgeon, known as an ophthalmologist, who will remove your damaged, scarred or diseased cornea and replace it with a healthier donated cornea from the eyes of a dead individual. In Malta, the first cornea transplant was carried out in the early 1980s.
There are two main types of corneal transplants: a penetrating, full thickness cornea transplant, involving transplanting all layers of the cornea from the legally-dead donor to the recipient eye (which is the only available option in Malta at the moment); and a lamellar or partial-thickness cornea transplant, which involves only replacing the diseased layers of the cornea, leaving the healthy layers intact.
In Malta, children under 16 may donate their eyes with their parents’ consent
A keratoplasty allows you to see more clearly by replacing an opaque cornea with one that will let light enter the eyes more easily.
But sometimes, a transplanted cornea can be rejected by the eye because it is seen as a foreign object trying to attack the body. This leads to cloudy vision, but another transplant can be performed and the patient is given anti-rejection medication.
Glaucoma, which is a leading cause of blindness in the US and affects one in 20 Americans, increases the likelihood of corneal transplant failure since the medication used to treat glaucoma can cause rejection of the donated healthy cornea.
The sclera is the white portion of the eye and can also be transplanted. Some eye conditions, such as tumours, require complete eyeball removal, while leaving nearby structures, such as muscles and fat, intact. An artificial eye implant or ‘fake eyeball’ that is covered with transplanted sclera is then used to fill the empty eye socket. The intact muscles can be attached to the transplanted sclera surrounding the ‘fake eyeball’, which allows it to move. Sclera is also used for the reconstruction of eyelids. A donated sclera is kept in glycerine or ethanol until it is used for transplantation.
Anyone, from the young and old, including the blind, those with glaucoma, cataracts, diabetes or hypertension, can donate their eyes to be used for research or, if suitable, for transplant. However, anyone with a potentially infectious disease, such as rabies, syphilis, hepatitis, septicaemia, HIV, Aids or someone who died from unknown causes is unable to donate their eyes due to the risk of transmission of infection.
Usually, eye donors have no age limits though this varies from country to country, depending on the regulations of the eye bank. In Malta, children under 16 may donate their eyes with their parents’ consent and people who have had cancer, must have been cancer-free for a minimum five years.
In the future, an alternative to eye transplants may eventually be the use of bionic eyes. A retinal implant and 24 electrodes developed by Bionics Vision in Australia has allowed three completely blind patients to see flashes or spots of light, shapes and the edges of doorways. This gives hope to millions of people around the world, who are either born blind or become progressively blind over time due to various eye disorders and old age.
Nevertheless, eye donations for the use of research will never cease.
Eyesight is one of the five main senses and plays an essential role in our quality of life. With the advance of transplant surgery, patients without functioning eyeballs have an increased chance of leaving the darkness behind them.
To become a donor, contact the Malta Transplant Support Group or register online for a donor card at www.transplantsupport.com.mt/application.htm. All patients are entitled to an eye transplant if they need it, depending on the severity of the illness, blood type and length of time on the waiting list. You will be able to choose which organs you wish to donate. Once you receive a donor card, you must sign and carry it on your person. Organs will be allocated to recipients based only on medical criteria. Factors such as gender, age, race, income, job title and celebrity status are not considered so you cannot buy yourself an organ.