Certified Ophthalmic Medical Technologist (COMT) Practice Exam

Which method of tonometry is best to use when the cornea is scarred and irregular?

1. Goldmann tonometry

2. TOnoPen or Pneumo-tonometer

3. Applanation tonometry

4. Non-contact tonometry

The correct answer is: TOnoPen or Pneumo-tonometer

The best method of tonometry to use when the cornea is scarred and irregular is the TonoPen or pneumotonometry. This is because these devices are designed to make accurate intraocular pressure measurements even in challenging scenarios where the corneal surface is not smooth. The TonoPen uses a small, lightweight probe that can adapt to the irregularities of the cornea, ensuring that measurements are taken more accurately despite any scarring. Non-contact tonometry, while a viable option for some situations, typically relies on a puff of air to measure pressure, which may not yield reliable results if the corneal surface is compromised. Goldmann tonometry and applanation tonometry, both of which require a stable, even corneal surface for accurate readings, would be less suitable in the presence of significant scarring or irregularities. Thus, the TonoPen or pneumotonometry stands out as the most reliable choice for measuring intraocular pressure under these conditions.