Signs and symptoms of albinism
Symptoms of albinism can involve the skin, hair, and eyes. The skin, because it contains little pigment, appears very light, as does the hair.
Although people with albinism may experience a variety of eye problems, one of the myths about albinism is that it causes people to have pink or red eyes. In fact, people with albinism can have irises varying from light gray or blue to brown.
(The iris is the colored portion of the eye that controls the size of the pupil, the opening that lets light into the eye.) If people with albinism seem to have reddish eyes, it's because light is being reflected from the back of the eye (retina) in much the same way as happens when people are photographed with an electronic flash.
People with albinism may have one or more of the following eye problems: They may be very far-sighted or near-sighted, and may have other defects in the curvature of the lens of the eye (astigmatism) that cause images to appear unfocused.
They may have a constant, involuntary movement of the eyeball called nystagmus.
They may have problems in coordinating the eyes in fixing and tracking objects (strabismus), which may lead to an appearance of having "crossed eyes" at times. Strabismus may cause some problems with depth perception, especially at close distances.
They may be very sensitive to light (photophobia) because their irises allow "stray" light to enter their eyes. It's a common misconception that people with albinism shouldn't go out on sunny days, but wearing sunglasses can make it possible to go outside quite comfortably.
In addition to the characteristically light skin and eye problems, people with a rare form of albinism called Hermansky-Pudlak Syndrome (HPS) also have a greater tendency to have bleeding disorders, inflammation of the large bowel (colitis), lung (pulmonary) disease, and kidney (renal) problems.
Albinism affects approximately 1 in 20,000 individuals, producing pigmentary deficiency, abnormal crossings of the temporal fibers in the optic chiasm, nystagmus, photophobia, variable visual acuity and, frequently, strabismus. The main subdivisions of albinism include oculocutaneous, ocular, and albinoidism (absence of pigment in localized areas; the pigment in the skin, hair and eyes is less than normal but does not affect the individual as severely as the oculocutaneous or ocular types). The literature reports as many as 20 variants of oculocutaneous albinism alone.
Oculocutaneous as well as ocular albinos exhibit similar ocular and visual dysfunction. The oculocutaneous albino patient manifests reduced acuity, photophobia, strabismus, significant refractive error with astigmatism, transillumination of the iris and globe, nystagmus, blonde fundus with visible choroidal vasculature, and macular hypoplasia. A super-normal EOG and ERG is also present.
Transillumination of the iris and globe results from insufficient uveal pigmentation and poor development of the retinal pigment epithelium. This leads to a funduscopic picture of a blond fundus with extensive areas of hypopigmentation and clearly visible underlying choroidal vasculature. The pigment of the RPE acts as a sink for incoming light. When the RPE is underdeveloped, light scatters within the eye, producing the subjective complaint of photophobia.
The level of visual acuity varies among albino patients according to the amount of ocular pigmentation present and the concomitant level of macular development. Ocular albinos have variable amounts of uveal pigmentation and the potential to have the best acuity (20/25 to 20/300) among albinos. Oculocutaneous albinos exhibits less pigmentation than their ocular albino counterparts and tend to have lower acuity levels (20/80 to 20/400).