OBJECTIVE To investigate the effects of phacoemulsification on the macula following uncomplicated phacoemulsification by optical coherence tomography (OCT). METHODS Eighty eyes of the senile cataract were chosen randomly. The uncomplicated phacoemulsification was performed. OCT was examined preoperatively and 1 week after the surgery. Preoperative visual acuity, the retinal thickness and phaco power were compared with those after surgery. RESULTS In 80 eyes, the preoperative mean foveal thickness was (142.9 +/- 16.7) micrometer and the postoperative (157.9 +/- 36.7) micrometer, the difference being not significant (P > 0.05). Three eyes had macular edema 1 week after surgery. In 11 eyes with Tyndall sign (+ +), the mean postoperative foveal thickness was thicker than the mean preoperative value (P < 0.05). In lower phaco power group, the mean postoperative foveal thickness was (156.2 +/- 18.3) micrometer and the higher phaco power group was (172.6 +/- 32.9) microm (P < 0.05). The best corrected visual acuity after surgery had a negative correlation with the retinal thickness. CONCLUSIONS The retinal thickening and macular edema can be found after uncomplicated phacoemulsification. The higher phaco power results in significant inflammation and thicker retina. The visual consequences were proportional to the degrees of macular thickening.