Cystoid macular edema (CME) remains a troublesome problem after cataract surgery and other types of ocular surgical procedures. It is recognized as the most frequent cause of decreased vision in patients following cataract surgery. Although the disease was first described more than 40 years ago, its cause is unclear, and all available therapeutic interventions, mainly based on theories regarding the pathogenesis of the condition, are of doubtful effectiveness and are still far from being satisfactory. Most published literature on the incidence and treatment of CME consists of small, retrospective case series and cannot provide reliable answers as to whether a given factor or intervention is associated with the occurrence or outcome of the disease.