A 68-year-old man underwent cataract extraction with phacoemulsification and insertion of a posterior chamber IOL. The first day postoperatively, he comes back with moderate epithelial and stromal edema. One week later, the edema is still present. Which is not a cause for his persistent corneal edema?
Answer: C) Epithelial downgrowth
Explanation: Among the causes of corneal edema the day following cataract extraction are elevated IOP (from inflammation, glaucoma, debris clogging the trabecular meshwork), corneal decompensation (low endothelial counts as in Fuchs dystrophy, endothelial chemical toxicity), or trauma to the endothelium. Epithelial downgrowth would not present immediately after surgery but would take weeks to develop. The corneal decompensation would overlie the area of the downgrowth, and a membrane may be seen on the endothelium and iris.