Impact of slanted lateral rectus recession on pediatric patients with convergence insufficiency intermittent exotropia.

Background: Convergence insufficiency intermittent exotropia (CIX(T)) is a common type of strabismus in children, characterized by greater ocular deviation at near fixation compared to distance fixation. This study aimed to explore impact of slanted lateral rectus recession (S-LRc) compared to conventional lateral rectus recession (LR) on pediatric patients with CIX(T).

Methods: This retrospective study enrolled pediatric patients with CIX(T) at Shanxi Aier Eye Hospital between June 2022 and December 2024. Pediatric patients with CIX(T) were divided into the S-LRc group and the LR group based on the surgical technique. In the S-LRc group, the lower pole of the lateral rectus muscle was recessed more than the upper pole to achieve greater correction at near. The primary outcome was postoperative horizontal eye position (orthotropia, overcorrection, or undercorrection). Secondary outcomes included near-distance deviation difference (NDD) and binocular visual function (simultaneous vision, fusion and static stereopsis) postoperatively.

Results: A total of 80 pediatric patients with CIX(T) were included in the study, divided into the LR group (n = 20) and the S-LRc group (n = 60). At six months postoperatively, there was a significant difference in distribution of postoperative horizontal eye position (12/1/7 vs. 55/3/1, P = 0.003) and NDD improvements (10 ± 4.29 vs. 13.37 ± 5.19, P = 0.012) between LR group and S-LRc group. In terms of binocular fusion, there were no significance in simultaneous vision (80.0% vs. 63.8%, P = 0.861), fusion (80.0% vs. 98.0%, P = 0.110) and static stereopsis (45.0% vs. 50.0%, P = 0.698) between LR group and S-LRc group.

Conclusions: There were significant difference in horizontal eye position and NDD improvement, but both LR and S-LRc performed comparably in binocular fusion function in pediatric CIX(T) patients. These findings highlight the potential of S-LRc in improving short-term alignment and convergence control in pediatric CIX(T). Longer follow-up studies are needed to assess recurrence and sustained binocular outcomes.

Clinical trial number: not applicable.