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
A 7 year old presents with left exotropia; right eye has 6/6 vision with normal fundus. Left eye has only close hand movements with subretinal yellow exudates and retinal detachment and telegiectatic vessels. Diagnosis is: 
Select and explain. 
A. Sympathetic ophthalmia, B. Coats disease, C. ROP, D. Familial exudative vitreous retinopathy (FEVR)
B: Coats disease
Answer: B: Coats disease 
Explanation: Ans. (b) Coats diseaseRef: Kanski 7/e, p. 582* Unilateral loss of vision with squint, exudates & RD points towards Coats diseaseFamilial exudative vitreoretinopathy (FEVR) Usually a positive family (AD, XLR) Bilateral but may be asymmetrical involved Unlike ROP not associated with LBW or prematurity Peripheral vascular telangiectasias Fibrovascular proliferation with tractional retinal detachment Massive subretinal exudates May present with leukocoria & squint