Objective 3

Question 1

What is the most commonly used filter used in a slit lamp examination?

Answer 1

cobalt blue (ultraviolet) filter.

Question 2

What is used in conjunction with the cobalt blue filter to allow the examiner to observe absent or roughened areas of the epithelium?

Answer 2

sodium fluorescein dye

Question 3

In addition to staining the corneal epithelium, what does fluorescein stain?

Answer 3

tears

Question 4

What test might be done in conjunction with fluorescein to evaluate tear production?

Answer 4

Break up time

Question 5

In what two forms can fluorescein be stored?

Answer 5

a liquid form or in the form of paper strips

Question 6

Which of these two forms is safer?

Answer 6

fluorescein strip (paper)

Question 7

When using the fluorescein strip to fit GP contacts, where does the examiner apply the strip to the patient’s eye?

Answer 7

superior bulbar conjunctiva

Question 8

Which filter makes blood vessels appear black and easier to observe?

Answer 8

Red Free (green) Filter

Question 9

Which filter is useful when evaluating a contact lens containing an ultraviolet filter?

Answer 9

Yellow Filter / Wratten Filter # 12A Hand held “wratten” filter can be used in conjunction with a cobalt blue filter and fluorescein to enhance the pattern behind a gas permeable contact lens. This is especially helpful with a contact lens containing an ultraviolet filter.

Question 10

What type filter is used in evaluation of tear film?

Answer 10

Polarizing Filters