This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Ocular Embryology& Anatomy, Subject name: Ophthalmology
Van Herick Test is used for: 
Select and explain. 
A. Measuring cells and flare, B. Measuring anterior chamber depth, C. Measuring angle, D. Measuring anterior chamber volume
B: Measuring anterior chamber depth
Answer: B: Measuring anterior chamber depth 
Explanation: Van Herick's method Measures anterior chamber depth with a slit lamp, focus at peripheral cornea near limbus at an angle of 60 deg It Compares anterior chamber depth with corneal thickness. Van Herick's Grading Grade 4 PAC >= CT Grade 3 PAC = 1/4 to 1/2 of CT Grade 2 PAC = 1/4 of CT Grade 1 PAC < 1/4 of CT CT - Corneal thickness PAC - Peripheral anterior chamber depth Grade 4 means likelihood of angle closure is rare