What is corneal edema and a typical cause?

• A. Fluid buildup in the corneal stroma causing hazy vision; often due to endothelial dysfunction or postoperative edema; can be related to contact lens overwear or glaucoma
• B. Inflammation of the conjunctiva due to allergy
• C. Increased intraocular pressure causing optic nerve damage
• D. Detachment of the retina at the macula

Answer: (A)

Corneal edema is fluid buildup in the corneal stroma that makes the cornea appear hazy and blur vision. The cornea stays transparent when its cells actively pump fluid out of the stroma; when endothelial function is impaired, fluid leaks in and the cornea swells. This can happen after eye surgery (postoperative edema), from chronic endothelial cell problems like Fuchs’ dystrophy, or from hypoxic stress such as overwearing contact lenses. Elevated intraocular pressure from glaucoma can also stress the endothelium and contribute to edema. The other conditions listed—conjunctival inflammation, optic nerve damage from high pressure, or retinal detachment—do not cause this fluid buildup in the corneal stroma, so they don’t describe corneal edema.