A form of albinism in which only the eyes are affected. The genes fail to make the usual amounts of a pigment called melanin. The typical reddish or violet eyes associated with albinism may not be present and instead, the eyes may be blue, green or even brown and physically appear to be normal. However, on examination by your eye doctor, it may show that there is very little pigment in the iris of the eye.
The hallmark of ocular albinism is in the fovea, the small area of the retina which affords acute vision. In ocular albinism, the fovea does not develop completely due to an absence of melanin pigment needed during pre-natal development. The eye cannot process sharp light images. Because the fovea does not develop well, it is difficult to correct vision completely with glasses.
Another problem present in ocular albinism is that nerves from the back of the eye to the brain do not follow the usual pattern of routing. A test called a visually evoked potential, which is performed like an EEG or brain wave test, can show this condition.
What causes it?
Albinism is an inherited genetic disorder. It affects one in 17,000 in the United States alone and affects people of all races.
What are the symptoms?
Light and glare sensitivity (photophobia), crossed eyes, lazy eye, and visual acuity problems. Albinos often have low vision problems and some are legally blind. Nystagmus (erratic rapid movement of the eyes back and forth) may also be present.
Eye problems often result from the lack of pigment. The iris, the colored part of the eye, lacks pigment in the albinic eye and therefore allows stray light to enter the eye where it normally wouldn't. This results in an exaggerated sensitivity to light and glare. In addition, the retina (the part of the eye that receives incoming light) does not develop normally in utero or process correctly after birth.
What can be done?
Because there is no way to correct the lack of pigment, treatment of the associated conditions is necessary. Surgery to correct Strabismus or Esotropia can correct crossed or lazy eyes, vision therapy can help improve the strength of the eye muscles, and optical aids can be prescribed to aid in daily activities. Bifocals, reading glasses, contact lenses, and bioptics can all help with low vision problems.