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
In a patient with anterior uveitis, what is the cause of decrease in vision due to posterior segment involvement? 
Select and explain. 
A. Visual Floaters, B. Inflammatory Disc Edema, C. Exudative Retinal Detachment, D. Cystoid macular edema (CME)
D: Cystoid macular edema (CME)
Answer: D: Cystoid macular edema (CME) 
Explanation: Most common cause of decreased vision in a patient with anterior uveitis is cystoid macular edema. In uveitis causes of decreased visual acuity are severe anterior segment inflammation, lens opacities, vitritis, optic nerve involvement, and retinal involvement such as edema, choroiditis, retinitis and scarring.