What is one of the purposes of performing pachymetry?

Pachymetry is the measurement of the corneal thickness, and one of its primary purposes is to diagnose corneal swelling, a condition known as corneal edema. When the cornea becomes swollen, its thickness increases, which can affect visual clarity and corneal function. By measuring the corneal thickness, practitioners can monitor the degree of swelling and assess the health of the cornea. This information can be vital for managing conditions such as Fuchs' dystrophy, post-surgical changes, or other disorders that may lead to corneal edema.

The other choices, while related to eye health, do not pertain specifically to the primary purpose of pachymetry. Intraocular pressure is assessed through tonometry, retinal health is evaluated using different diagnostic tools such as fundus cameras or optical coherence tomography (OCT), and refractive errors are measured with techniques like retinoscopy or autorefractometry. Each of these assessments serves its purpose, but they do not involve the measurement of corneal thickness that pachymetry specifically addresses.