Quiz 2

Question 1

The keratomileusis is designed to measure the cornea at the

Answer 1

Visual Center

Question 2

The topographer

Answer 2

Provides a computer generated map of corneal curvature

Question 3

A _______ lens may be used to extend the range of the keratometer from 52.00 to 61.00 Diopters

Answer 3

+1.25

Question 4

The following keratometer readings indicate what type of astigmatism? 45.00@20 / 46.00@110

Answer 4

With the rule

Question 5

Given the following information calculate the residual astigmatism (CRA) if the patient is fit with a rigid contact lens:
Rx: +6.00 +0.25 x80
Ks: 42.25 / 43.75 @ 80

Answer 5

Rx: 0.25 WTR
Ks: 1.50 WTR

Difference: 1.25 is the calculated residual astigmatism.

Front Surface toric required.

Question 6

The patient’s K readings are 46.00@180 / 43.75@90. The measurable corneal astigmatism is ____ Diopters.

Answer 6

2.25 Diopters (ATR) because the flattest is at 90 (or 30 degrees either way)

Question 7

The area of the cornea with the steepest curvature is the

Answer 7

Apex.

Question 8

The following keratometer readings indicate what type of astigmatism? 43.00 @145/ 41.00 @55

Answer 8

Regular because 90 degrees apart but Oblique because they are out of the 30 degrees zone.

Question 9

Given the following information calculate the residual astigmatism (CRA) if the patient is fit with a rigid contact lens
Rx: -2.00 -1.50 x180
Ks: 41.50 / 43.25 @ 90

Answer 9

Rx: 1.50 WTR
Ks: 1.75 WTR

Calculated is 0.25 (it’s fine)

Question 10

Before using any keratomileusis it is necessary to:

Answer 10

Focus the eyepiece