Keratometry 3%

Question 1

*What is the generic name for Keratometer?

Answer 1

Ophthalmoteter

Question 2

Keratometer uses what type of mirror?

Answer 2

Front surface

Question 3

What surface does the Keratometer measure?

Answer 3

The anterior surface of the K

Question 4

*Keratometer measures in what?

Answer 4

D or mm’s

Question 5

*What part of the cornea does the keratometer measure?

Answer 5

Central 3mm (corneal cap)

Question 6

In keratometry.

Question 6

*In keratometry the prism splits light into 2 images. What are they split into?

Answer 6

Horizontal and Vertical Meridians

Question 7

*Keratometry is the starting point for _____ fitting

Answer 7

CL

Question 8

The Difference between vertical and horizontal meridians =

Answer 8

Diopters of corneal astig

Question 9

For Keratometry the room light must be ____

Answer 9

dim

Question 10

You must _____the eye piece before performing Keratometry

Answer 10

focus

Question 11

You must align____ with pts out most canthus

Answer 11

Canthus marker

Question 12

How do you focus eye piece of Keratometer?

Answer 12

Turn until you have 3 complete circles with the plus and minus lined up together

Question 13

Explain how to perform manual keratometry

Answer 13

Dim the lights and focus your eye piece. Align canthus marker with pts outer canthus. Have pt blink and open wide. Keep circles in sharp focus. Turn the knobs until the plus signs intersect and the minus signs intersect. Then rotate the keratometer until all of those intersecting lines are perfectly overlapped. This gives you the axis. Then read drums. Horizontal reading recorded first(some prefer flatter then steeper meridian then axis)

Question 14

When converting readings from Keratometer from mm’s to D
Each 0.05mm=_______
0.5mm radius=________
1D change in K=________

Answer 14

Approx 0.25D
Approx 2.5 D
Approx 0.2 mm radius change

Question 15

Method of Keratometry that is more accurate than traditional keratometer, is objective, expensive, and good K surface is a must.

Answer 15

IOL Master (aka AUTOMATED Laser Keratometry)

Question 16

Laser automated keratomter is keratometry with the ______

Answer 16

IOL master

Question 17

How many peripheral measuring marks are there in IOL Master?

Answer 17

6

Question 18

When performing IOL master be sure all ________are visible and lying as concentric as possible to the _______

Answer 18

6 marks
2 auxillary circles

Question 19

What’s most important when doing IOL Master?

Answer 19

Optimally focus 6 marks

Question 20

Good ________is a must when performing Keratometry with IOL master.

Answer 20

tear film (have pt blink)

Question 21

What are reasons for “Error” message when doing Laser automated Keratometer(IOL master)?

Answer 21

out of focus, maladjustment, artifacts, surface irregularities.

Question 22

_________astigmatism means cornea is steeper in the vertical meridian. Plus cynlinder axis is between 60-12-0 degrees.

Answer 22

With-the-rule astigmatism

Question 23

_________astigmatism means K is steeper in the horizontal meridain. Plus cylinder axis is between 0-30 degrees or 150-180 degrees.

Answer 23

Against-the-rule astigmatism

Question 24

Axis is between 30-60 or 120-150 degrees.

Answer 24

Oblique astigmatism