Comparison of bilateral/unilateral lateral rectus recession and unilateral recession-resection for intermittent exotropia: a Meta-analysis

Abstract

Aim: To compare the effectiveness of unilateral recession-resection (R&R) and bilateral/unilateral recession (BLR/ULR) for treatment of basic type of intermittent exotropia [IX(T)].

Methods: A comprehensive literature search was performed using PubMed, EMBASE, and the Cochrane Library, to identify randomized controlled trials and comparative studies regarding the effectiveness of R&R and BLR/ULR for IX(T). Based on which, a Meta-analysis was then performed in terms of long-term success rate, overcorrection rate, and recurrence rate.

Results: Nine studies in total satisfy the specified eligibility criteria. BLR is at disadvantage to R&R at a short-term follow-up [<2y, OR 0.56 (0.33-0.94) for success rate; OR 2.11 (1.17, 3.81) for undercorrection rate]. However, BLR achieved a higher success rate [OR 2.49 (1.61, 3.86)] and a lower undercorrection rate [OR 0.40 (0.23, 0.71)], compared to that of R&R at a long-term follow-up (>2y). There is no significant difference was found in overcorrection rate, regardless of the length of follow-up time [OR 0.85 (0.41, 1.75)]. In the treatment for small-angle IX(T), the final outcome was significantly different between the groups, demonstrating a more successful alignment [OR 0.37 (0.18, 0.74)] and a lower undercorrection [OR 3.50 (1.28, 7.26)] in the R&R group than in the ULR group. While for moderate-angle IX(T) (20 PD-25 PD), the effectiveness of R&R and ULR is quite equivalent with similar success rate [OR 1.08 (0.65, 1.79)] and undercorrection rate [OR 0.89 (0.54, 1.48)].

Conclusion: As regard to the effect of BLR and R&R, R&R shows an advantage over BLR at short term. But, BLR is more effective in the long term for the basic type IX(T) in children. R&R surgery should be a better choice for the treatment of small-angle IX(T) of ≤20 PD than ULR. However, both of ULR and R&R are recommended for moderate-angle IX(T) from 20 PD to 25 PD.

Keywords: intermittent exotropia; moderate-angle exotropia; recess-resect; unilateral lateral rectus recession.

Figure 1. Flow chart of search process [based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Guidelines].

Figure 2. The rate of success comparing bilateral lateral rectus recession and unilateral lateral rectus recession and medial rectus resection.

Figure 3. Stratified analyses of success rate comparing bilateral lateral rectus recession and unilateral lateral rectus recession and medial rectus resection according to the duration of follow-up.

Figure 4. The rate of overcorrection comparing bilateral lateral rectus recession and unilateral lateral rectus recession and medial rectus resection.

Figure 5. The rate of recurrence comparing bilateral lateral rectus recession and unilateral lateral rectus recession and medial rectus resection.

Figure 6. Stratified analyses of undercorrection rate comparing bilateral lateral rectus recession and unilateral lateral rectus recession and medial rectus resection according to the preoperative angle of deviation.

Figure 7. Tests for publication bias of the success rate.