CPOA Clinical Procedures 5 — Questions and Answers
Question 1: When performing applanation tonometry, the fluorescein mires should be adjusted until the inner edges of the two semicircles are:
- Overlapping fully
- Just touching (inner margins meeting) (Correct answer)
- Separated by 1 mm
- Vertically aligned
Correct answer: Just touching (inner margins meeting)
The correct endpoint for Goldmann tonometry is when the inner edges of the two fluorescein semicircles just touch each other.
Question 2: A patient is unable to read the 20/400 letter at three meters. The next step for recording acuity is to test:
- Pinhole acuity
- Counting fingers (CF) (Correct answer)
- Light perception (LP)
- Gross hand motion
Correct answer: Counting fingers (CF)
When a patient cannot resolve any chart letter, acuity is recorded as counting fingers (CF) at the distance the patient correctly identifies finger count.
Question 3: During automated perimetry, a reliability index called 'false positive rate' measures how often the patient responds when:
- A stimulus is presented outside the blind spot
- No stimulus is actually presented (Correct answer)
- The stimulus is presented in the blind spot
- Two stimuli are shown simultaneously
Correct answer: No stimulus is actually presented
False positives occur when patients click the button during 'catch trials' where no stimulus is shown, indicating trigger-happy or unreliable responses.
Question 4: Which instrument measures the back vertex distance (BVD) between the cornea and the spectacle lens?
- Lensometer
- Distometer (Correct answer)
- Keratometer
- Pachymeter
Correct answer: Distometer
A distometer (vertex distance gauge) measures the distance from the back surface of the spectacle lens to the anterior cornea, important for high prescriptions.
Question 5: When recording blood pressure in a pre-exam health screening, the cuff should be placed:
- Over clothing on the forearm
- Directly on the skin of the upper arm (Correct answer)
- Around the wrist only
- Above the elbow on bare skin pointing downward
Correct answer: Directly on the skin of the upper arm
The cuff must be placed directly on the skin of the upper arm, 2–3 cm above the antecubital fossa, for an accurate measurement.
Question 6: Which pupil finding, if present in one eye, would be noted as a relative afferent pupillary defect (RAPD)?
- Both pupils dilate equally when light is shone in either eye
- The tested eye fails to constrict briskly when light swings from the fellow eye (Correct answer)
- The pupil constricts in bright light and dilates in darkness normally
- The pupil is irregular in shape under slit-lamp
Correct answer: The tested eye fails to constrict briskly when light swings from the fellow eye
In a RAPD (Marcus Gunn pupil), the affected eye's pupil paradoxically dilates when light is swung to it from the normal eye, indicating optic nerve or retinal asymmetry.
Question 7: Proper hand hygiene between patients in an optometric clinic should consist of:
- Rinsing with water alone for 5 seconds
- Using an alcohol-based hand rub or washing with soap and water for at least 20 seconds (Correct answer)
- Wiping hands on a dry cloth
- Using gloves for every patient without handwashing
Correct answer: Using an alcohol-based hand rub or washing with soap and water for at least 20 seconds
CDC guidelines require either an alcohol-based sanitizer or soap-and-water handwashing for at least 20 seconds to reduce cross-contamination between patients.
CPOA Clinical Procedures 5
When performing applanation tonometry, the fluorescein mires should be adjusted until the inner edges of the two semicircles are: