FREE COA Tonometry and Keratometry Questions and Answers

Question 1

A patient with high, against-the-rule astigmatism requires an intraocular pressure check using Goldmann applanation tonometry.
To obtain an accurate measurement, how should the ophthalmic assistant orient the tonometer prism?

Accepted Answer

Align the prism so the red line is on the axis of the minus cylinder.

Answer

Center the prism with the 0-degree mark aligned horizontally.

Answer

Rotate the prism to the axis of the plus cylinder.

Answer

The orientation of the prism does not affect the reading.

Question 2

When performing manual keratometry, the ophthalmic assistant is unable to get clear, stable mire images, and they appear to be pulsating or jumping. This finding is most indicative of which of the following?

Accepted Answer

A poor tear film or dry eye.

Answer

Incorrect eyepiece focus.

Answer

High intraocular pressure.

Answer

A dense nuclear sclerotic cataract.

Question 3

An ophthalmic assistant is checking the calibration of a Goldmann tonometer using the supplied calibration bar. At the '0' setting, what should happen when the dial is turned slightly forward (e.g., to +0.05)?

Accepted Answer

The feeler arm should fall toward the patient.

Answer

The feeler arm should fall toward the examiner.

Answer

The feeler arm should remain perfectly still.

Answer

The measurement drum should lock into place.

Question 4

A patient's intraocular pressure is measured as 25 mmHg with applanation tonometry. However, a pachymetry reading reveals a central corneal thickness of 610 microns. How does this corneal thickness likely affect the IOP measurement?

Accepted Answer

It may cause an artificially high IOP reading.

Answer

It has no significant effect on the IOP reading.

Answer

It may cause an artificially low IOP reading.

Answer

It only affects non-contact tonometry, not applanation.

Question 5

While performing keratometry, the ophthalmic assistant obtains two different readings: 44.50 D at 180 degrees and 42.00 D at 90 degrees. This difference is used to quantify which of the following?

Accepted Answer

Corneal astigmatism

Answer

Intraocular pressure

Answer

Corneal diameter

Answer

Axial length

Question 6

Which of the following scenarios would MOST likely lead to an inaccurate intraocular pressure reading when using a non-contact tonometer (NCT)?

Accepted Answer

The patient is squeezing their eyelids tightly.

Answer

The patient has a large pupil.

Answer

The patient has mild nuclear sclerosis.

Answer

The patient recently used lubricating eye drops.

A patient with high, against-the-rule astigmatism requires an intraocular pressure check using Goldmann applanation tonometry.To obtain an accurate measurement, how should the ophthalmic assistant orient the tonometer prism?

A patient with high, against-the-rule astigmatism requires an intraocular pressure check using Goldmann applanation tonometry.
To obtain an accurate measurement, how should the ophthalmic assistant orient the tonometer prism?