This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cornea, Subject name: Ophthalmology
[{'content': 'A 20-year-old boy came with complaints of sudden pain in the left eye with loss of vision. On examination, left eye cornea was hazy and on looking down, there was a bulging in the lower eyelid. Retinoscopy shows scissoring reflex and oil drop sign was positive in both eyes, what is the diagnosis? \nSelect and explain. \nA. Corneal dystrophy, B. Keratoconus, C. Pathological myopia, D. Keratoglobus', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans: (b) KeratoconusRef: Kanski, Clinical Ophthalmology, 8th edition, Page 218-220; A.K. Khurana\'s Comprehensive Ophthalmology, 6th edition, Page 131KERATOCONUSDefined as non-inflammatory bilateral ectactic condition of cornea in which the cornea assumes a conical shape secondary to stromal thinning and protrusion.The diagnosis is keratoconus with acute hydrops.Etiology: Not clear.Symptoms: Defective vision due to progressive myopia and irregular astigmatism.Signs:Window reflex is distorted.Slit lamp:Thinning and ectasia of cornea.Fleischer"s ring at the base of the cone.Vogt\'s line (deep stromal striae due to stretching of cornea).Retinoscopy: Scissoring/Yawning reflex.Distant direct ophthalmoscopy: Oil Droplet Reflex.Munson\'s Sign: Bulging of lower lid on downward gaze.Management:Spectacle correction in early cases.Rigid gas permeable contact lenses.Intra corneal ring segments (INTACS).Collagen cross linking.Deep anterior lamellar keratoplasty / penetrating keratoplasty.Remember:Acute hydrops is a complication of keratoconus where the descemet\'s membrane ruptures and aqueous enters the cornea.', 'role': 'assistant'}]