Long-term outcomes of unilateral lateral rectus recession versus recess-resect for intermittent exotropia of 20-25 prism diopters

Abstract

BackgroundThe purpose of this study was to compare surgical outcomes of unilateral lateral rectus recession (ULR) and unilateral recess-resect (RR) for intermittent exotropia of 20-25 prism diopters (PD).MethodsIn this retrospective study, ULR was performed on 82 patients and RR on 98 patients for the treatment of intermittent exotropia of 20-25 PD with a follow-up period of 24 months or more. The main outcome measures were postoperative exodeviation angles and final success rates. A surgical success was considered to be an alignment within 10 PD.ResultsThe mean follow-up duration after the surgery was 53.8 ± 26.4 months in the ULR group and 52.5 ± 27.4 months in the RR group (p = 0.482). The mean deviation angles at postoperative 1 day were -0.49 PD (esodeviation) in the ULR group and -1.98 PD in the RR group. Subsequently, at postoperative 1 week, 1 and 3 months, the deviations became more exotropic in the ULR group than in the RR group (p < 0.05). However, the mean deviation angles at 6 months, 1 and 2 years and at the final follow-up did not significantly differ between the two groups. Surgical success at the final follow-up was achieved for 50 patients (60.9%) in the ULR group and 55 patients (56.1%) in the RR group (p = 0.511).ConclusionsULR is an effective surgical method for treatment of moderate-angle intermittent exotropia of 20-25 PD, showing results similar to those of RR.

Long-term surgical outcomes and factors for recurrence after unilateral lateral rectus muscle recession

“…Several investigators reported groups with <45 PD of exodeviation showed better success rate than ≥45 PD of exodeviation in BLR 12 13. However, previous comparative studies between ULR and two-muscle surgeries for small to moderate angle exotropia showed no statistically significant differences in success rate 5 6 14. Therefore, further long-term prospective studies with large sample sizes are necessary to confirm our findings and to optimise the procedure for 20–24 PD IXT.…”

“…However, surgical tables as a guideline for ULR are still under debate. Several investigators performed 9.5 mm for 21–24 PD of IXT5 and others use 8.0 mm even for 25–30 PD of IXT 11. Nevertheless, we have modified the surgical table, with 8.5 mm recession for 20 PD and 9.0 mm for 21–24 PD of IXT in ULR to confirm the findings and plan further studies.…”

“…The authors performed 8 mm recession and 77.7% of patients achieved ≤5 PD exodeviation/esodeviation. A more recent study compared the long-term surgical results of the ULR and RR for 20–25 PD of exotropia 5. The study reported that 63.4% of the ULR group and 60.2% of the RR group achieved alignment ≤10 PD at 2 years after surgery.…”

“…ULR is more advantageous than two-muscle surgery; advantages include lower overcorrection rate, shortened operation time and preservation of unoperated muscles for future surgery 5 10. The absence of overcorrection cases in the present study supports the findings of low rate of overcorrection.…”

“…Bilateral lateral rectus muscle recession (BLR) or unilateral lateral rectus muscle recession (ULR) and medial rectus muscle resection (RR) are traditional surgical procedures in IXT 2 3. ULR was described as another surgical option for small to moderate angle exotropia in 19504 with favourable success rate 5 6. However, the long-term outcomes in a large number of patients are unclear 6–8…”