Albinism is a group of hereditary diseases which affect the way the body produces or spreads pigment. People with albinism have a decreased quantity or lack of pigment in the eyes, hair and skin.
As a whole, there are 2 main categories of albinism, both of which cause vision problems including decreased vision. The first type is called oculocutaneous albinism or OCA. OCA causes low pigmentation in the eyes, hair and skin.
The second type is called ocular albinism. Ocular albinism mainly affects the eyes, while skin and hair are normal or close to normal in color. Children with ocular albinism have no exceptional visible characteristics, making eyesight issues the first symptoms of albinism.
Albinism is called by a genetic mutation which is passed from the parents to the child. The mutation disrupts the production of melanin – the pigment which protects skin from UV light. Melanin is important to the correct development of the eye. Without melanin, the retina, the light-sensitive tissue in the back part of the eye and the optic nerve fibers which send images to the brain may not develop correctly.
Some of the symptoms include:
- Involuntary, rapid eye movement
- Strabism
- Sensitivity to bright light (photophobia)
- Short-sightedness, farsightedness or astigmatism
- Monocular vision (depending on the vision in one eye)
- Foveal hypoplasia, a condition in which the retina does not develop normally before birth and in early childhood
- Issues with the optic nerve – nerve signals do not use usual pathways
People with albinism can have vision which varies from normal to heavily impaired. Vision at a close range is usually better than seeing at a distance. As a whole, those who have the least melanin have the worst vision.
Albinism cannot be treated. Symptoms it causes can be, however. For example, strabismus can be treated with glasses or a surgical intervention. Glasses can also help improve eyesight and decrease photosensitivity. For children with bad vision devices such as handheld magnifying glasses can be of use. For older children and adults, glasses with small telescopes over the lenses can be used.