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?

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.