This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cornea, Subject name: Ophthalmology
Corneal thickness is measured using - 
Select and explain. 
A. Pachymetry, B. Keratometer, C. CT scan, D. Aesthisiometry
A: Pachymetry
Answer: A: Pachymetry 
Explanation: Ans. is 'a' i.e., Pachymetry o Corneal Pachymetry: It is the method to measure the corneal thicknesso The following are the other methods of measuring corneal thickness:a) Ultrasoundb) Ultrasound biomicroscopy and very high frequency ultrasoundc) Optical slit lamp pachymetryd) Specular microscopy basede) Scanning slit based Orbscanf) Optical Coherence Tomography (OCT)g) Optical low coherence reflectometryh) Confocal microscopy through focusingi) Laser Doppler interferometry