What is Ocular Albinism?
Ocular albinism is a genetic condition in which eyes lack melanin pigmentation. People with ocular albinism have little to no pigmentation in the iris and the retina, which is critical for normal vision. Unlike oculocutaneous albinism, which is characterized by a lack of pigmentation in the hair, skin, and eyes, ocular albinism just affects the eyes. Therefore, it may not be evident simply by looking at someone that they have ocular albinism.
What causes ocular albinism?
Ocular albinism is a genetic abnormality, and is present at birth for people affected. All forms of albinism, including ocular albinism, are caused by a mutation in one of the genes responsible for producing melanin. The mutation may result in a substantially reduced amount of melanin, or in some cases, no melanin at all. Most cases of ocular albinism are caused by a mutation in the GPR143 gene. Men are much more likely to be affected; ocular albinism is extremely rare in women.
What are the effects of ocular albinism?
The effects of ocular albinism are present at birth and do not worsen over time. In fact, parents of children who have been newly diagnosed may take comfort in learning that in many cases, children with ocular albinism actually slightly improve as they move into adolescence and adulthood. While this is a genetic condition with no cure, many children acclimate to the condition, and as a result, the effects may seem less pronounced over time.
Common effects of ocular albinism include
- Involuntary, rapid movement of the eye (nystagmus)
- Blurred vision
- Sensitivity to light
- Inability to perceive depth
- Crossed eye and/or eyes that look in different directions
- In some cases, the eye may have a unique appearance and blood vessels may be evident
- Many people with ocular albinism will also have a refractive error, causing nearsightedness, farsightedness, or a stigmatism
- In some cases, people with ocular albinism will exhibit a head tilt, which is often a way to minimize the complications of nystagmus.
How is ocular albinism diagnosed?
Because ocular albinism is quite rare and many of the symptoms mimic other visual impairments, a diagnosis can be challenging, particular if the affected person’s eyes do not look irregular. Ocular albinism is generally diagnosed after a comprehensive evaluation of symptoms, a detailed family medical history, an extensive examination of the eyes, and genetic testing for gene mutations.
How is ocular albinism treated?
Because ocular albinism is a genetic condition, there is no cure. However, frequent check-ups with a specialist are encouraged to lessen the potential for complications. Because individuals with ocular albinism may be especially sensitive to light, sunglasses or special filter glasses may be helpful. Additionally, refractive errors should be diagnosed and treated as early as possible, as corrective lenses will maximize the affected person’s sight. In some rare cases, extraocular muscle surgery may be performed to improve the conditions caused by nystagmus.