COT Ophthalmic Instrumentation and Equipment Maintenance

Question 1

A Goldmann applanation tonometer is being calibrated using the calibration bar. At the 20 mmHg position, a reading of 22 mmHg is obtained. What action should be taken?

Accepted Answer

Remove the instrument from service and schedule repair

Answer

Continue using the instrument; a 2 mmHg deviation is within acceptable limits

Answer

Re-zero the tonometer and repeat the measurement only at 0 mmHg

Answer

Switch to a non-contact tonometer for all patients that day

Question 2

Which disinfection method is recommended between patients for a Goldmann applanation tonometer prism to prevent transmission of adenovirus and other pathogens?

Accepted Answer

Wipe with 70% isopropyl alcohol and allow to air dry for at least 5 minutes

Answer

Autoclave sterilization at 121°C for 15 minutes

Answer

Soak in 1:10 diluted bleach for 30 seconds

Answer

Rinse with sterile saline and dry with gauze

Question 3

A keratometer is producing mire images that appear distorted and asymmetric even after lens cleaning. The MOST appropriate next step is to:

Accepted Answer

Verify accuracy by measuring a steel calibration sphere of known radius

Answer

Perform the measurement anyway and document the irregularity in the chart

Answer

Replace the eyepiece lens immediately

Answer

Use the autorefractor reading as a substitute

Question 4

When cleaning the objective lens of a slit lamp biomicroscope, the correct technique is to:

Accepted Answer

Use a lens-cleaning solution with a lint-free cloth, wiping gently from center outward

Answer

Use a dry cotton swab in a vigorous circular motion to remove debris

Answer

Apply 70% isopropyl alcohol directly to the glass surface with a paper towel

Answer

Rinse with tap water and pat dry with a soft cloth

Question 5

Which sterilization method is MOST appropriate for ophthalmic surgical instruments with heat-sensitive components?

Accepted Answer

Ethylene oxide (EtO) gas sterilization

Answer

Steam autoclave at 134°C

Answer

Dry heat oven at 160°C for 2 hours

Answer

Boiling in distilled water for 10 minutes

Question 6

During routine maintenance checks, which action should be performed DAILY on a non-contact tonometer (NCT)?

Accepted Answer

Perform a calibration check using the instrument's built-in verification procedure

Answer

Replace the internal air puff mechanism filter

Answer

Disassemble and clean the nozzle tip in an autoclave

Answer

Lubricate the joystick mechanism with medical-grade oil