S-BLR Versus C-BLR for CI-IXT in Children

Convergence Insufficiency Intermittent Exotropia (CI-IXT) Clinical Trial

— SCCIXT  

Official title:

Slanted Bilateral Lateral Rectus Recession Versus Conventional Bilateral Lateral Rectus Recession for Convergence Insufficiency Intermittent Exotropia in Children

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT04064112
• Other study ID #: 2019C-PEDIG
• Status: Completed
• Phase: N/A
• Start date: October 18, 2019
• Est. completion date: February 11, 2023

Study information

• Verified date: December 2023
• Source: Eye & ENT Hospital of Fudan University
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

This is a multi-center, randomized single-blind controlled trial to compare the effectiveness of S-BLR with C-BLR for the treatment of CI-IXT in children.

Specific Aim 1 (Primary): To compare the surgical successful rate of S-BLR with C-BLR for the treatment of CI-IXT in children.

Specific Aim 2 (Secondary): To study the suboptimal surgical outcomes between S-BLR and C-BLR for the treatment of CI-IXT in children.

Description:

Using conventional surgical procedures, higher postoperative near undercorrection and/or distant overcorrection rates were observed in CI-IXT. To achieve better outcome, S-BLR was introduced. Previous studies showed its efficacy in reducing near exodeviation, distant exodeviation, and NDD. So far, only limited studies have directly evaluated the surgical outcomes between S-BLR and C-BLR. The pilot study done by Snir et al included 12 patients with S-BLR and 6 patients with C-BLR and the success rates of S-BLR vs C-BLR were 92% vs 0 at one-year follow-up. The retrospective study done by Song et al included 17 patients undergoing S-BLR and 14 patients undergoing C-BLR. With stricter successful criteria, the success rates of S-BLR vs C-BLR were 35% vs 7% at six-month follow-up. A large randomized trial is needed to compare the surgical successful rate and suboptimal surgical outcomes of S-BLR with C-BLR in children with CI-IXT.

The proposed trial will be conducted in 6 different study sites working in the field of pediatric ophthalmology and strabismus.Each site will have one certified surgeon to do all surgeries. Under general anesthesia, the LR recession is performed using an inferior-temporal fornix incision. For S-BLR, the lower horn of the LR is recessed based on near exodeviation and the upper horn is recessed based on distant exodeviation. For C-BLR, the LR is recessed based on distant exodeviation. Surgical dose is according to the largest preoperative exodeviation at distance (6 meters) or near (1/3 meter) by the prism and alternate cover test(PACT). The extent of the recession is based on Parks' surgical dosage schedule.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 200
• Est. completion date: February 11, 2023
• Est. primary completion date: February 19, 2022
• Accepts healthy volunteers: No
• Gender: All
• Age group: 5 Years to 12 Years

Eligibility

Inclusion Criteria:

• Exodeviation at least 15 at distance (6 meters);

• Exodeviation at most 50 at near (1/3 meter);

• Greater exodeviation at near than at distance by 10 or more;

• Control score of exodeviation greater than 3;

• Best-corrected visual acuity of 20/40 or better in the worse eye, and interocular difference of less than 2 lines;

• Myopia5.00D, hyperopia3.0D and anisometropia=2.5D based on cycloplegic refraction

• Optical correction needed for at least 2 weeks before evaluation of exodeviation:

myopia0.5D or astigmatism1.5D in either eye, or anisometropia1.0D;

• Written informed consent given by participants and their parents or legal guardians.

Exclusion Criteria:

• Prior strabismus surgery or botulinum toxin injection;

• Coexisting vertical deviation greater than 5, oblique muscle dysfunction, torsional deviation, dissociated vertical deviation, A-V pattern, or other conditions requiring horizontal rectus transposition, oblique surgery or vertical rectus surgery;

• Paralytic or restrictive strabismus;

• Lateral incomitance (greater exodeviation in right or left gaze position than in primary position by 5 or more with appropriate optical correction);

• Ocular disease other than strabismus or refractive error;

• Previous intraocular or refractive surgery;

• Craniofacial malformations affecting the orbit;

• Significant neurological disorders;

• Birth date34 weeks or birth weight1500 gram.

Abbreviations: CI-IXT, convergence insufficiency intermittent exotropia; D, diopter.

Related Conditions & MeSH terms

• Convergence Insufficiency Intermittent Exotropia (CI-IXT)
• Exotropia
• Ocular Motility Disorders

Intervention

Procedure:
• S-BLR
Surgery of slanted bilateral LR recession for CI-IXT patients
• C-BLR
Surgery of conventional bilateral lateral rectus recession for CI-IXT patients

Locations

Country	Name	City	State
China	Eye & ENT Hospital of Fudan University	Shanghai

Sponsors (7)

Lead Sponsor	Collaborator
Chen Zhao	AIER Eye Hospital (Kunming), Children's Hospital of Fudan University, Renmin Hospital of Wuhan University, Shanghai Jiao Tong University School of Medicine, Tianjin Eye Hospital, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine

Country where clinical trial is conducted

China, 

References & Publications (12)

BURIAN HM, SPIVEY BE. THE SURGICAL MANAGEMENT OF EXODEVIATIONS. Am J Ophthalmol. 1965 Apr;59:603-20. No abstract available. — View Citation

Burian HM. Exodeviations: their classification, diagnosis and treatment. Am J Ophthalmol. 1966 Dec;62(6):1161-6. doi: 10.1016/0002-9394(66)92570-0. No abstract available. — View Citation

Chen X, Fu Z, Yu J, Ding H, Bai J, Chen J, Gong Y, Zhu H, Yu R, Liu H. Prevalence of amblyopia and strabismus in Eastern China: results from screening of preschool children aged 36-72 months. Br J Ophthalmol. 2016 Apr;100(4):515-9. doi: 10.1136/bjophthalmol-2015-306999. Epub 2015 Aug 10. — View Citation

Choi DG, Rosenbaum AL. Medial rectus resection(s) with adjustable suture for intermittent exotropia of the convergence insufficiency type. J AAPOS. 2001 Feb;5(1):13-7. doi: 10.1067/mpa.2001.111137. — View Citation

Chun BY, Kang KM. Early results of slanted recession of the lateral rectus muscle for intermittent exotropia with convergence insufficiency. J Ophthalmol. 2015;2015:380467. doi: 10.1155/2015/380467. Epub 2015 Jan 26. — View Citation

Farid MF, Abdelbaset EA. Surgical outcomes of three different surgical techniques for treatment of convergence insufficiency intermittent exotropia. Eye (Lond). 2018 Apr;32(4):693-700. doi: 10.1038/eye.2017.259. Epub 2017 Dec 22. — View Citation

Kraft SP, Levin AV, Enzenauer RW. Unilateral surgery for exotropia with convergence weakness. J Pediatr Ophthalmol Strabismus. 1995 May-Jun;32(3):183-7. doi: 10.3928/0191-3913-19950501-12. — View Citation

Ma L, Yang L, Li N. Bilateral lateral rectus muscle recession for the convergence insufficiency type of intermittent exotropia. J AAPOS. 2016 Jun;20(3):194-196.e1. doi: 10.1016/j.jaapos.2016.01.014. Epub 2016 May 6. — View Citation

Raab EL, Parks MM. Recession of the lateral recti. Effect of Preoperative fusion and distance-near relationship. Arch Ophthalmol. 1975 Aug;93(8):584-6. doi: 10.1001/archopht.1975.01010020568002. — View Citation

Snir M, Axer-Siegel R, Shalev B, Sherf I, Yassur Y. Slanted lateral rectus recession for exotropia with convergence weakness. Ophthalmology. 1999 May;106(5):992-6. doi: 10.1016/S0161-6420(99)00522-9. — View Citation

Wang B, Wang L, Wang Q, Ren M. Comparison of different surgery procedures for convergence insufficiency-type intermittent exotropia in children. Br J Ophthalmol. 2014 Oct;98(10):1409-13. doi: 10.1136/bjophthalmol-2013-304442. Epub 2014 May 19. — View Citation

Yang HK, Hwang JM. Surgical outcomes in convergence insufficiency-type exotropia. Ophthalmology. 2011 Aug;118(8):1512-7. doi: 10.1016/j.ophtha.2011.01.004. Epub 2011 Apr 7. — View Citation

* Note: There are 12 references in all — Click here to view all references

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	surgical successful rate	Surgical successful cases/total cases. The successful criterion is a postoperative residual deviation at near and distance between 10 PD of exophoria/tropia and 5 PD of esophoria/tropia with near-distance difference <10 PD.	at 12 month
Secondary	suboptimal surgical rate	suboptimal surgical cases/total cases. Suboptimal surgical outcomes include: undercorrection, overcorrection, diplopia, torsional deviation, A-V pattern, abduction limitation and reoperation.	at 12 month