This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anatomy, Subject name: Ophthalmology
Which diagnostic procedure is not done in a dilated pupil? 
Select and explain. 
A. Gonioscopy, B. Laser inferometry, C. Fundus examination, D. Electroretinography
A: Gonioscopy
Answer: A: Gonioscopy 
Explanation: Ans. a. Gonioscopy (Ref: Khurana 5/e p578; Basics and Clinical Science Course. American Academy of Ophthalmology, 2012-13; Sec 10, p46)Gonioscopy is not done in a dilated pupil.Gonioscopy is done in dark room with minimum slit lamp light. Pupil contraction will falsely open up the angle. Likewise pupillary dilatation will cause crowding of the iris at angle and angle appears as closed."By gonioscopy angle structures are assessed, especially relationship of root of iris and trabecular meshwork in normal physiological state. To avoid pupillary contraction, it is done in dark room with minimum slit lamp light." - Basics and Clinical Science Course. American Academy of Opthalmology, 2012-13; Sec 10, p46