How Common Is Ocular Albinism Or Is It A Rare Disease?

Albinism is a genetic defect that can present itself in the association of eye defects in the form of two diseases classified as oculocutaneous albinism and ocular albinism.

Oculocutaneous albinism consists of eye defects as well as skin and appendageal defects also whereas ocular albinism presents itself only in the eyes and skin is usually spared. Oculocutaneous albinism is much more prevalent in comparison to ocular albinism when coming to the defects in the eye and its function.

According to various data statistics collected to date, oculocutaneous albinism type 1 is the most common among all subtypes of albinism and has been found to have a prevalence of 1: 17000 to 1: 20000, which is quite rare. Oculocutaneous albinism type 2 is even rarer with a prevalence of 1: 36000. In a few states of the American countries, this prevalence rises to about 1: 10000. Ocular albinism is rarest of them all with a prevalence of nearly about 1: 50000 or 20 per million. In contradiction to such statistics of the world, few African countries show a much more prevalence of ocular albinism in the range of 1: 2000 to 1: 5000 which is quite higher than the rest of the world in numbers.

In the syndromic association of hermansky pudlak syndrome with ocular albinism, the prevalence in Puerto Rico is found to about 1: 2700 which also is quite high when comparing to the world statistics. It is also associated with higher mortality due to various other organ systems’ involvement. One of the causes of such a low prevalence of ocular albinism over oculocutaneous albinism is that it is an X linked defect, due to which the prevalence also falls to this reason.⁽¹⁾

On the basis of racial characteristics, ocular albinism is found in approximately equally in all the races whereas on the other hand oculocutaneous albinism is more found in African American origins. Ocular albinism is an x linked disorder due to which it is commonly found in males and very rarely found in females representing a skewed distribution of the statistics. Whereas in contrast to Ocular albinism, Oculocutaneous albinism has an autosomal origin so it is equally found in both males and females.

Since it is a hereditary disorder inherited from the parents or the grandparents, it usually presents an early age and gets diagnosed by infancy or early childhood. Very rarely it can also go till adulthood without getting noticed.

The prognosis of ocular albinism is very variable and depends upon the functional defects created due to it. The defect of visual acuity caused by it is usually not treatable to the normal and only palliative care can be given to the patient. Retinal defects may or may not get cured after the surgical treatment of the condition has been followed. Optic nerve defects are also permanent in nature.⁽¹⁾

Conclusion

There is no disparity in the fact that ocular albinism is a very rare disorder and being an x-linked disorder becomes rarer in the females. It has a very low prevalence and it gets diagnosed at an early age because of being the genetic defect. The functional abnormalities of the eye are not commonly encountered with ocular albinism and only the structural non-significant defects like the color of the iris are seen. There is no need to worry if the color of the eye is affected and the visual acuity is normal because it will not lead to any complications.

It can be safely concluded that ocular albinism is not a common disorder and a rare disorder in fact. Only certain areas are showing the difference in the prevalence of the disease and these are more located in American and African areas. Puerto Rico is a country which shows more syndromic associations than the individual ocular albinism.

References:

https://emedicine.medscape.com/article/1216066-overview

Also Read:

How Common Is Ocular Albinism Or Is It A Rare Disease?