Effects of slanted bilateral lateral recession vs conventional bilateral lateral recession on convergence insufficiency intermittent exotropia:a prospective study

AIM:To observe the surgical effects of slanted bilateral lateral recession(S-BLR)versus conventional bilateral lateral recession(C-BLR)in convergence insufficiency intermittent exotropia(CI-IXT).METHODS:Using a randomized,double-blind,prospective design,22 patients with CI-IXT who were admitted to Renmin Hospital of Wuhan University from July 2019 to December 2020 were included.Patients were randomly divided into either S-BLR or C-BLR group for their subsequent strabismus surgery.All patients were followed up for 12mo.Near deviation,distant deviation,and neardistance difference(NDD)were measured in all patients.RESULTS:Twelve months after surgery,NDD improvement was 10(8,13)prismatic degrees(PD)in S-BLR group and 3(1,6)PD in C-BLR group(P=0.011).The near deviation of S-BLR group was 0(-2,2)PD,while that of C-BLR group was-4(-6,-3)PD(P=0.005).Before and after surgery,the difference in the distant deviation between the two groups was not statistically significant.There was no statistically significant difference in near stereopsis between the two groups(P=0.380)at 12mo.The success rate at 12mo after operation was 90.91%and 72.73%in the two groups(P=0.280).CONCLUSION:CI-IXT patients treated with S-BLR have better surgical outcomes than those treated with C-BLR,which indicates S-BLR is a safe and effective operation pattern.