CLINICAL TECHNIQUES - Goldmann and Gonioscopy

Question 1

What principle is goldmann’s tonometry based on?

Answer 1

Imbert-Fick principle
P= F/A

Force of applanation is directly proprtion to IOP when area of applanation is 3.06nm –> at this area of contact, the additional forces of corneal rigidity and surface tension are balanced.

Question 2

What is used in the tonometer head to allow for splitting operator’s view of tear meniscus?

Answer 2

Prisms, allows for precise adjustment.

Question 3

When is the IOP falsely low?
When is the IOP falsely high?

Answer 3

See table.

Question 4

Which gonioscopy lenses are direct?

Which gonioscopy lenses are indirect?

Answer 4

Direct gonioscopy lens: Koeppe, Barkan, Swan-Jacob, RIchardson

Indirect gonioscopy lens: Goldmann, Zeiss, Posner, Sussman.