Objective To observe corneal refractive change after 20-G and 23-G incision vitreoretinal surgery.Methods It was a prospective case-control study.Forty-four patients (44 eyes) who underwent 23-G vitreoretinal surgery were selected for a 23-G group and 48 patients (48 eyes)who underwent 20-G vitreoretinal surgery during the same period were selected tor the 20-G group.Corneal topography was performed before surgery and 3 days,2 weeks,1 month and 3 months postoperatively.The corneal topography parameters were recorded and the data were analyzed by ANOVA,independent samples t test and x2 test.Results ①Corneal topography showed no significant differences in shape preoperatively compared to 3 months postoperatively (x2=5.26,P＞0.05).②In the 20-G group: corneal curvature was reduced at 1 and 3 months postoperatively compared to preoperative parameters (t=1.08,-3.67,P＜0.05).Corneal astigmatisn 3 days,2 weeks and 1 month postoperatively was higher than preoperative parameters (t=0.53,0.9,0.56,P＜0.05).The regular parameters of the corneal surface were higher 3 days postoperatively compared to preoperative parameters (t=0.74,0.63,1.08,P＜0.05).In the 23-G group:corneal curvature was higher 3 days and 2 weeks postoperatively compared to preoperative parameters (t=0.37,0.46,P＜0.05).Corneal astigmatism and the regular parameters of the corneal surface were higher 3 days postoperatively compared to preoperative parameters (P＜0.01).③The 20-G group had lower corneal curvature parameters (P＜0.05),higher astigmatism parameters (t=0.81,1.08,P＜0.05),and higher corneal surface regularity (P＜0.05) compared to the 23-G group.Conclusion Astigmatism recovered to preoperative levels in 1-3 months postoperatively,and corneal curvature was lower 3 months postoperatively compared to preoperative curvature.In the 23-G group,the corneal refractive status recovered to preoperative levels in from 2 weeks to 3 months postoperatively.Postoperative corneal curvature was lower and astigmatism was higher in the 20-G group compared to the 23-G group.Thus,23-G vitreoretinal surgical wounds heal faster and result in smaller corneal refractive changes.