This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Neuro-Ophthalmology, Subject name: Ophthalmology
Regarding acute papilloedema: 
Select and explain. 
A. Blind spot increases, B. Visual acuity normal; colour vision decrease, C. Colour vision normal; visual acuity decreases, D. There is always associated optic nerve inflammation
B: Visual acuity normal; colour vision decrease
Answer: B: Visual acuity normal; colour vision decrease 
Explanation: Ans: b (Visual acuity normal; colour vision decrease)Ref: Khurana, Vision and Neuro Ophthalmology pg. 288The other options are features of papilitis.In chronic papillodema, there may be enlargement of blind spot. In papillodema, visual acuity is normal, pupillary reactions are brisk i.e., there is no RAPD in contrast to papilitis. Papillitis is optic neuritis due to inflammation.Clinical featuresPainful ocular movementsColor vision is decreasedVisual acuity decreasedRAPD Usually unilateral