Eye Tests and Diagnosing Albinism
Albinism is an inherited trait. People who are albinos have a mutation in the gene that codes for the pigment melanin. This pigment is responsible for hair, eye and skin colour, so the classically recognised albino has pale pink eyes, white hair and very pale skin.
Although this is true, there is a range of different types of albinism in which there may be some pigment and it can be localised in different places in the eyes, skin or hair. Some people who are albino may not realise it because they have blue, hazel or even brown eyes, blonde hair and pale skin, which is not really that unusual. The problem is that their skin does not have enough melanin to protect against sun damage, so any exposure to sun, on a holiday for example, has the potential to cause serious skin and eye damage.
Albinism and the Eyes
Most types of albinism affect the whole body but there are rare types that only affect the eyes. Someone with this condition is said to have ocular albinism. The genetic mutation responsible is in a gene that codes for the enzyme tyrokinase. This enzyme acts on the amino acid tyrosine and converts it into a pigment molecule. Without the working enzyme, no pigment is made. In ocular albinism, the gene is altered in such a way than melanin production is not stopped completely; small amounts of pigment are made, so there can be some eye colour.Unfortunately, albinism, whatever its effects on the appearance of the eyes, skin and hair, always changes the way that they eyes work. People with albinism always have poor vision and an eye test is now used as the main diagnostic method to identify people who may be albinos.
The mutation in the pigment gene also affects the way that the retina develops when a baby is growing in the womb. Most people with albinism have vision problems that can’t be helped by glasses or contact lenses and many are classed as legally blind. Their retina does not have the right nerve connections with the optic nerve and brain, so their vision will never improve.