Purpose: To assess changes in the thickness of the subfoveal retina and choroid after phacoemulsification using enhanced depth imaging optical coherence tomography (EDI-OCT). Methods: A prospective study was conducted on 100 patients. The subfoveal choroidal thickness (SFCT) was measured at 7 points and the retinal thickness was measured at 5 points (before surgery, and 1 day, 1 week, 1 month, and 3 months after surgery). Results: The foveal choroidal thickness showed a thickening trend (but p > 0.05). Compared to the change from baseline to day 1, the changes from baseline were significantly different at nasal 3 mm and 6 mm at all other time points (all p < 0.05). Choroidal thickness changes at temporal 6 mm correlated negatively with intraocular pressure (IOP) at 1 week and 1 month; changes at nasal 3 mm correlated negatively with IOP at 1 week and 1 month (all p < 0.05); changes at nasal 3 mm, temporal 3 mm, and temporal 6 mm correlated with average ultrasonic energy. Choroidal thickness changes correlated with ultrasound (US) time at day 1. Conclusions: Uncomplicated phacoemulsification led to changes in choroidal thickness. IOP and choroidal thickness changes were negatively correlated. The foveal retinal thickness was correlated with age. SFCT was correlated with sex, axial length, IOP, and US time.