This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Ophthalmology
Which of the following diagnostic procedure is not done in dilated pupil? 
Select and explain. 
A. Gonioscopy, B. Fundus examination, C. Laser inferometry, D. Electroretinography
A: Gonioscopy
Answer: A: Gonioscopy 
Explanation: Ans. a. Gonioscopy Gonioscopy is not done in a diluted pupil. (AI1MS May 2014 repeat) 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 Ophthalmology, 2012-13; Sec 10, p46