This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Retina, Subject name: Ophthalmology
Tabular vision is caused by 
Select and explain. 
A. Retinitis pigmentosa, B. Narrow angle glaucoma, C. Nuclear cataract, D. Papillodema
A: Retinitis pigmentosa
Answer: A: Retinitis pigmentosa 
Explanation: Ans. a (Retinitis pigmentosa). (Ref Basak, Ophthalmology, 2nd ed., 203)As the primary OAG advances the glaucomatous field defect due to generalized constriction of peripheral field along with double arcuate scotoma leads to tubular vision, in which only central vision remains.Causes of tubular vision include:# CRAO with sparing of cilioretinal artery.# High myopia# POAG# Retinitis pigmentosa}(Mnemonic: CHOR)