Low vision Mx of Albinism

Question 1

What is Oculocutaneous Albinism (OCA)?

Answer 1

A group of four autosomal recessive disorders caused by either a complete lack or a reduction of melanin in the melanocytes resulting in hypopigmentation

Question 2

What is the VA like with Oculocutaneous Albinism?

Answer 2

6/19 (occassioanlly better) to worse than 6/60 due to foveal hypoplasia

Question 3

What type of movement is nystagmus ?

Answer 3

It is usually pendular and horizontal however can also be jerk

Question 4

What does the fundus look like?

Answer 4

Usually lacks pigment and choroidal vessels are visible with degrees of foveal hypoplasia

Question 5

What happens to the optic chiasm with OCA?

Answer 5

Has fewer uncrossed fibres than normal, so they majority cross to the contralateral hemisphere

Question 6

What are OCA associated syndromes?

Answer 6

• Chediak-Higashi
  -Hermansky-Pudlak
  -Waardenburg

Question 7

What is OA1?

Answer 7

It is usually x-linked and occasionally autosomal recessive
- female carriers asymptomatic but may show iris translucency
- VA 6/12 TO 6/90

Question 8

What will the OCT show?

Answer 8

Thinning of the foveal retina and subfoveal choroidal

Question 9

When will surgery for nystagmus take place?

Answer 9

When the head posture is sufficiently large and stable, extraocular muscle surgery may be considered to transfer the null point closer to primary gaze

Question 10

When will a prism be used for nystagmus?

Answer 10

For smaller anomalous head postures, prism may be used to transfer the null point closer to the primary gaze

Question 11

What management is given to those who have convergence decreases nystagmus?

Answer 11

A pair of 7pd BO prism with -1D spherical power added to compensate for induced accommodation and to induce convergence for far viewing

Question 12

How do tints and shields help glare control?

Answer 12

yellow, amber and reddish tints absorb shorter wavelengths of light
- Hat or sun visor