This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cornea and sclera, Subject name: Ophthalmology
Pachymeter is used to measure 
Select and explain. 
A. Corneal thickness, B. Corneal diameter, C. Corneal density, D. Conjuctival thickness
A: Corneal thickness
Answer: A: Corneal thickness 
Explanation: A pachymeter is a medical device used to measure the thickness of the eye's cornea. It is used to perform corneal pachymetry prior to refractive surgery, for Keratoconus screening, LRI surgery and is useful in screening for patients suspected of developing glaucoma among other uses. Ref khurana 6/e