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Question 1

What are you looking for in anterior vitreous?

Answer 1

Looking for floaters and Shafer’s sign (Tobacco dust)

Question 2

What is Shafer’s sign?

Answer 2

When there is a retinal tear, RPE cells detach from Bruch’s membrane. Clumps float into the vitreous liquid and some travel to berger’s space (The space behind the lens)

Question 3

What does Shafer’s sign look like?

Answer 3

RPE clumps are brown.

Question 4

What should you also look out for when doing anterior vitreous?

Answer 4

Detachments can cause haemorrhages so look out for red blood cells which apprear white in colour.

Question 5

What are the advantages of anterior vitreous?

Answer 5

Helps detect retinal detachments

Question 6

What are the disadvantages of anterior vitreous?

Answer 6

1. Not much to see if nothing wrong.
2. Harder to perform on older patients if not dilated

Question 7

In specular reflection endothelium which purkinje image are we looking for? And why do we get this image?

Answer 7

We can see purkinje image 1. The reflection from anterior cornea and the tears.
And purkinje image 2 which is the duller one coming from the posterior cornea. We are interested in look at purkinje image 2.

We get the purkinje images because i=r
Angle of incident is equal to angle of reflection.

Question 8

What are the advantages of specular reflection endothelium?

Answer 8

1. Useful for checking for changes in endothelial cell especially in CL aftercare
2. Endothelial cells are not replaced so vital to keep an eye on them
3. Cheaper than a confocal microscope

Question 9

What are the disadvantages of Specular reflection endothelium?

Answer 9

1. Only checks a very small portion of the endothelium
2. Need a good slit lamp and skilled operator

Question 10

Which purkinje image are we on for specular reflection anterior lens?

Answer 10

purkinje image 3, anterior lens, front of the lens.