Clinical trial NCT04064112: S-BLR Versus C-BLR for CI-IXT in Children
Official title: Slanted Bilateral Lateral Rectus Recession Versus Conventional Bilateral Lateral Rectus Recession for Convergence Insufficiency Intermittent Exotropia in Children
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Convergence Insufficiency Intermittent Exotropia (CI-IXT)
Lead sponsor: Eye & ENT Hospital of Fudan University
Sponsor class: OTHER
Collaborators: name: Children's Hospital of Fudan University
name: Xinhua Hospital, Shanghai Jiao Tong University School of Medicine
name: Shanghai Jiao Tong University School of Medicine
name: Tianjin Eye Hospital
name: Renmin Hospital of Wuhan University
name: AIER Eye Hospital (Kunming)
First posted: 2019-08-21
Enrollment: 200
Sex: ALL
Minimum age (years): 5
Maximum age (years): 12
Standard ages: CHILD
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief 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.

Detailed 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.

Eligibility criteria: 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.

Primary outcomes:
measure: surgical successful rate
timeFrame: at 12 month
Secondary outcomes:
measure: suboptimal surgical rate
timeFrame: at 12 month
Other outcomes:
Locations:
city: Shanghai
country: China
facility: Eye & ENT Hospital of Fudan University
Study officials:
affiliation: Eye & ENT Hospital of Fudan University
name: Chen Zhao, Doctor
role: STUDY_CHAIR
affiliation: Xinhua Hospital, Shanghai Jiao Tong University
name: Xiaoli Kang, Doctor
role: PRINCIPAL_INVESTIGATOR
affiliation: Tianjin Eye Hospital
name: Yueping Li, Doctor
role: PRINCIPAL_INVESTIGATOR
affiliation: Renmin Hospital of Wuhan University
name: Lianhong Zhou, Doctor
role: PRINCIPAL_INVESTIGATOR
affiliation: Eye & ENT Hospital of Fudan University
name: Jing Yao, Doctor
role: STUDY_DIRECTOR
affiliation: Children's Hospital of Fudan University
name: Chenhao Yang, Doctor
role: PRINCIPAL_INVESTIGATOR
affiliation: AIER Eye Hospital (Kunming)
name: Jiangtao Xu, Doctor
role: PRINCIPAL_INVESTIGATOR
References:
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
citation: BURIAN HM, SPIVEY BE. THE SURGICAL MANAGEMENT OF EXODEVIATIONS. Am J Ophthalmol. 1965 Apr;59:603-20. No abstract available.
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.