Abstract: Macular thickness is increased in patients after phacoemulsification with intraocular lens implantation. The increase in macular thickness may lead to visual impairment. The mechanisms of macular thickness increase are still unknown.  The relative factors that affect the macular thickness after cataract surgery include systemic factors, ocular factors, surgical factors and medical factors. Inflammation plays a major role in the mechanisms which causes the break drown of the bloodretinal barrier that leads to the increase in macular thickness. Medicine that focuses on its mechanisms may prevent SCME and treat SCME.  (Int Rev Ophthalmol, 2014, 38:   340-345)