Vision

Understanding Oculocutaneous Albinism

eyeAlbinism comes in two forms, ocular (OA) and oculocutaneous (OCA). In OA, only the eyes or retina are affected by the lack of pigment. With OCA, the eyes, skin and hair all show a lack of melanin pigment.

Typically people with OCA have fair to very fair skin and white or light colored hair. They can have a much greater risk of sun damage to the skin. The iris (the colored part of the eye) may also not have any pigment causing it to be pink or very lightly colored. This can make the eyes very light-sensitive. The vision issues with OCA are the same as OA — reduced visual acuity, nystagmus, strabismus (misalignment of eyes) and decreased stereoscopic vision (depth perception).

There are four types of OCA, with type 1 and 2 being most common. Some types are more common in certain ethnic groups or from geographic regions. All four types of OCA are autosomal recessive, meaning the person must have mutations on both copies of the gene. The most accurate way to tell which type of OCA a person has is to conduct genetic testing. An estimated 1 in 20,000 people worldwide are born with OCA.

  • OCA Type 1 – typically has a complete lack of pigment in the hair, skin and eyes. People will show vision symptoms similar to OA.
  • OCA Type 2 – individuals can have a minimal amount of pigment to a moderate amount, including dark blonde/reddish hair and eyes that are blue. Vision symptoms are similar to OA.
  • OCA Type 3 – is more difficult to diagnose by appearance alone. People show a lack of pigment in skin and hair, but vision symptoms are less severe.
  • OCA Type 4 –symptoms are similar to type 2, but incidence is more common in people of Japanese or Korean decent.

Oculocutaneous Albinism is a condition that affects an individual for their entire life, but can be managed with some care and understanding. The key to proper management is understanding what type you are dealing with and its genetic implications.

 

Sources:

http://ghr.nlm.nih.gov/condition/oculocutaneous-albinism

http://rarediseases.about.com/od/rarediseasesa/a/082704.htm

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