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.

Post-operative strabismus control and motor alignment for basic intermittent exotropia

AIM：To assess strabismus control and motor ocular alignment for basic exotropia surgery at 5y follow-up.METHODS：The medical records of 80 consecutive patients aged less than 17 years of age,who underwent surgery for basic exotropia by a single surgeon between years 2000 to 2009 and completed a minimum of 5y follow-up post-operatively were reviewed.Pre- and post-operative characteristics were documented at 1wk,6mo,1,3 and 5y follow-up.Subjects at 5-year follow-up were assigned to the success group if they had a postoperative angle of deviation within 10 prism diopters of exotropia or within 5 prism diopters of esotropia for distance on prism cover test,and had moderate to good strabismus control.The remaining subjects were assigned to the failure group.RESULTS：Post-operative surgical success at one week was 75%,which decreased to 41% at 5y follow-up.The success group was noted to have more patching pre-operatively（P=0.003）.The duration of patching a day（P=0.020） and total duration of patching preoperatively（P=0.030） was higher in the success group.Surgical success at 1y（P=0.004） and 3y（P=0.002） were associated with higher surgical success at 5y follow-up.CONCLUSION：Post-operative motor alignment and strabismus control for basic exotropia surgery at 1y and beyond is associated with higher exotropia surgery success at 5-year follow-up.There is an association between pre-operative patching and 5-year surgical success of basic intermittent exotropia surgery.