Certified Paraoptometric (CPO) Practice Exam 2025

In comparison to Goldmann tonometry, how is Tonopen generally regarded in terms of accuracy?

1. More accurate

2. Equally accurate

3. Less accurate

4. Not comparable

The correct answer is: Less accurate

Tonopen is generally regarded as less accurate than Goldmann tonometry. Goldmann tonometry is considered the gold standard in measuring intraocular pressure (IOP) and relies on a precise and controlled method to obtain measurements that are widely accepted in clinical practice. In contrast, while Tonopen is a more portable and easier-to-use device, it can be influenced by various factors, such as the examiner's technique and the condition of the cornea. These variables can lead to discrepancies in readings, making its accuracy slightly less reliable compared to the Goldmann method, especially in certain clinical situations. It is important to note that, despite its lower accuracy in some settings, Tonopen can still provide valuable measurements in situations where Goldmann tonometry may not be practical or possible, such as in pediatric patients or in outpatient settings. However, when comparing the two, Goldmann tonometry remains the preferred method for accurate IOP assessment in a wide range of patients.