Ma J, et al. - The possible risk factors and clinical effects of black areas in small-incision lenticule extraction were examined in this case-control study. From September 2012 to July 2017, 31 cases and 126 controls were recruited from the database of a single center. Researchers used logistic regression analysis to evaluate the possible risk factors for black areas between cases with black areas and controls without black areas. The study findings suggested that black areas in small-incision lenticule extraction could be caused by repeated suction, presence of surface debris, and a lower energy of the femtosecond laser and these factors could result in rough dissection and slower recovery of visual acuity.