Megalocornea is associated with A/E –
Megalocornea is a condition where the cornea is larger than normal, typically over 13 mm in diameter in infants. It's different from other corneal conditions like keratoconus or congenital glaucoma. I remember that megalocornea can be associated with certain genetic syndromes. For example, Marfan syndrome is known to have ocular manifestations including megalocornea. Then there's also the possibility of Down syndrome, but I think the more classic association is with Marfan.
Wait, the question says "associated with A/E –" which probably means "associated with all except" or "associated with which of the following except". But since the correct answer is the last option, maybe the options were Marfan, Down, etc., and the correct answer is a condition not typically linked. Let me think. If the options are Marfan, Down, Congenital glaucoma, and another, then congenital glaucoma might not be associated. Wait, no, congenital glaucoma can have corneal enlargement due to increased intraocular pressure. But megalocornea is a structural issue, not due to pressure. So congenital glaucoma's corneal enlargement is called "glaucomatous corneal enlargement" or "buphthalmos", which is different from megalocornea. So if the options include congenital glaucoma, that would be the correct answer here.
So the core concept is distinguishing between structural megalocornea and corneal enlargement due to other causes like glaucoma. The correct answer would be the one that's not a known association. For example, Marfan is associated with megalocornea, Down syndrome can have it too. But if the options include congenital glaucoma, that's the exception. Therefore, the correct answer is the one that's not associated. So the explanation would need to clarify the difference between megalocornea and buphthalmos. The clinical pearl is that megalocornea is a structural condition, while buphthalmos is due to pressure. High-yield fact: megalocornea is non-glaucomatous, whereas corneal enlargement in glaucoma is due to pressure and is reversible if treated. So the correct answer is the option that's not linked, like congenital glaucoma. Therefore, the explanation should highlight that megalocornea is a primary structural issue, not a secondary effect of pressure.
**Core Concept**
Megalocornea is a structural corneal enlargement (diameter >13 mm in infants) distinct from corneal edema or glaucomatous enlargement. It is often associated with genetic syndromes like Marfan syndrome, Down syndrome, or congenital rubella, but not with secondary causes like congenital glaucoma.
**Why the Correct Answer is Right**
Congenital glaucoma causes corneal enlargement (buphthalmos) due to elevated intraocular pressure, leading to corne