Certified Ophthalmic Assistant Practice Exam

Which instrument is used to measure the thickness of the cornea?

1. Autorefractor

2. Ophthalmoscope

3. Pachymeter

4. Phoropter

The correct answer is: Pachymeter

The pachymeter is specifically designed to measure the thickness of the cornea. This measurement is crucial in various clinical settings, particularly in diagnosing and managing conditions such as glaucoma, where corneal thickness can influence intraocular pressure measurements. In addition, pachymetry is essential for pre-operative assessments for procedures like LASIK, as it helps determine the suitability of the cornea for surgery. Regarding the depth of the anterior chamber, certain types of pachymeters, particularly those with optical coherence tomography capabilities, can also provide measurements of the anterior chamber depth. However, traditional devices primarily focus on corneal thickness. The accuracy in measuring these parameters plays a significant role in eye health management, making the pachymeter an invaluable tool for ophthalmic assistants. In contrast, instruments like the autorefractor, ophthalmoscope, and phoropter have different primary functions related to vision assessment, retinal examination, and refractive error correction, respectively. While they are critical in an eye care setting, they do not measure corneal thickness or anterior chamber depth directly.