Testing & Diagnosis

How is Albinism Diagnosed?

In a clinical diagnosis, an ophthalmologist or optometrist is generally able to identify albinism in a person with no or very little melanin (pigment) by looking into the back of the eye. There will be no or very little colour in the retina, and the area where vision is focussed will lack the different cells that form the fovea – this is called foveal hypoplasia. This applies to both Ocular Albinism (OA) and Oculocutaneous Albinism (OCA). It becomes tricky where a little melanin is present and there is some evidence of a foveal pit.

If there are other albinism traits present such as nystagmus, strabismus or unexplained symptoms of lack of acuity or depth perception and very pale skin, it may add to the ability to diagnose albinism. Along with a slow or delayed development of vision, this is the basis for a diagnosis in babies and small children. In some cases, genetic testing may be necessary to make a definite diagnosis (genetic diagnosis). Look for more information under the “Types of Albinism” and “Genetics” tabs.

NOTE: Visual acuity alone cannot be relied on as a good predictor of a person’s vision problems. Someone with relatively good acuity (6/24) can have difficulty with some functional tasks, while someone with worse acuity (6/60) might not have any real problems performing some daily activities. Albinism in particular is more complex than the visual acuity, and there are differences within each typing and each acuity reading.

Further information in this section comes under the following headings:

  • Babies and preschoolers
  • School aged children
  • Testing adults
  • Resources

Babies and pre-schoolers

In the first few weeks of life, the vision in all babies is underdeveloped and while they may have light perception and see shadows or shapes at first, they gradually develop visual acuity during those first 6 weeks, and will learn to favour a parent’s face. Visual acuity in a newborn is generally very poor, but by four months of age, they have developed or learnt a range of visual skills. All newborns also have trouble focusing, so “crossed eyes” are common.

Parents and doctors often pick up something is wrong when the child reaches the age of about 6 or 8 weeks and is not following objects (tracking) or reacting to facial expressions (delayed development). A baby with albinism may appear to have very poor vision at first and it is important to understand that this will improve.

The eye structures in albinism (lack of melanin in the retina, foveal hypoplasia and misrouting of the optic nerves) do not change and cannot be corrected, but the use of these structures does improve. It takes many more months for children with albinism to fully develop their potential sight. Therefore if a measurement of sight is requested for a baby, the answer at that stage is frequently given as that of “legally blind” (6/60 or more), as sight development is delayed. This can be devastating to parents, especially if they are not told about the normal related delay or the difference between “blind” or “legally blind”, or that frequently they develop better vision as they grow and catch up.

“Legally blind” does not mean total blindness. This is simply the term used for vision greater then 6/60 for government and other assistance. Your child can see, and this will continue to improve.  

The ophthalmologist may use cards with patterns or pictures held in front of the baby or toddler to gauge their reaction to what they may see. The level of visual impairment can be approximated in babies and toddlers, but cannot be measured with greater accuracy until they are about 3 years old. Accuracy increases further once they can recognise and verbalise letters and numbers.

Other eye conditions not specific to albinism, but that commonly occur with albinism can be identified during testing, including refractive errors (long or short sightedness), strabismus (“lazy” or turned eye) or photophobia. Most respond well to early remedial action such as glasses and patching, preventing further loss of vision. Providing the right sort of toys and books, lighting or glare protection can assist as sight develops further. Don’t let the diagnosis stop you from continually using and stimulating their vision with books, mobiles, coloured flags and toys in bold, high contrast colours, with large, simple patterns and drawings. This also helps them in other areas, including social, literacy, visual-motor coordination, emotional and communication development.

School aged children

By the time they reach school age and are able to identify letters on the Snellen chart (the letter chart used to measure vision), a more accurate measurement of vision is possible. Many parents find that the sight measurement has improved considerably at this age, due to continued development, but generally not due to any change in the structure of the eye. The child’s vision will continue to mature and develop until around the age of 8 years. The vision of those who have a little melanin in the eye may develop more pigment than others, with a slight improvement in vision.

It is important to continue to have regular check ups to identify or monitor any non albinism conditions mentioned in the previous section, allowing for treatment or rehabilitation, updating of prescription glasses, to prevent further vision loss and maximise the vision they have. Any remedial action or surgery is best undertaken before the age of 8 while the brain is still adapting to the way you see. After this age it is harder for the brain to recognise changes, although not impossible.

While the clinical measurement may not change very much, if at all, functional vision often improves as the child gains experience and learns to use what sight they have in combination with other senses and visual memory cues (I’m at the park and I remember that the swing is near the big tree).

PWA also learn ways of managing around their vision (copying others, questioning etc) and may appear to others as having “good” vision. This is a coping mechanism to fit in with their peers. Don’t call this out publicly but be aware that even adult PWA can “fake it” in the world of good vision.

Also be aware that contrast makes a big difference; seeing and pointing out a small yellow object on a black background then tripping over the cream coloured family dog lying on the cream carpet is quite common. The former doesn’t mean great / better vision, it just means the eyes could discern it better, either the colour difference, a shadow, or a movement etc have helped.

Albinism is for life – it cannot be cured, but many adults with albinism like to say “if you are going to have a disability, albinism is the best one to have, because you can lead a normal and fulfilling life with just a few accommodations”. Adults with albinism live independent lives, marrying, working and having a family, unlike some other genetic differences. Your child is no different.

Further information on testing and diagnosis:

  • Coming very soon!

Testing Adults

Optometrists will test vision for long or short sightedness, the supply of glasses, contact lenses and prescription sunglasses, but most people with albinism will also have regular checks with an ophthalmologist.

In Australia the Snellen chart may be used for distance visual acuity in each eye separately. This chart has one large letter at the top and gradients of visual acuity on the side. A measurement of 6/24 to 6/60 in the better eye indicates moderate visual impairment (at 6/24 the visually impaired person will have to be as close as 6 metres to an object, to see what a fully sighted person can see 24 metres away). Those with measurements over 6/60 are considered to be legally blind. You may see this written as a number over 20. This is the USA equivalent: 6 metres (Aus) equals 20 feet (USA). It doesn’t mean anything different except metric vs decimal.

The logMAR notation may be used to test visual acuity. The logMAR records acuity and can be for one or both eyes. 1.0 = 6/6 & 0.1 = 6/60 and an N series measurement is used for near visual acuity (eg N10). When nystagmus or photophobia is considered in addition to these measurements, the impairment may be considered greater.

Don’t be alarmed if an optometrist or ophthalmologist uses only their fingers to test. This is for people who are unable to read the Snellen chart for various reasons or to confirm a previous notation. This could be their age, or their vision, and is another way of measuring visual acuity.

Resources