An interventional study of S-BLR and C-BLR in Convergence Insufficiency Intermittent Exotropia (CI-IXT), sponsored by Chen Zhao. Completed at 1 site in China. Open to participants aged 5 Years to 12 Years. Per ClinicalTrials.gov, last updated 2023-12-20.
Sponsored by Chen Zhao · Not applicable, Interventional, and Treatment
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.
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.
58 studies on the registry are indexed under Exotropia; 13 are open to participants now.
This study's enrollment of 200 is above the median of 50 across 49 interventional studies indexed under Exotropia.
Browse Exotropia studies →This is the only study on the registry with Chen Zhao as lead sponsor.
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Exclusion Criteria:
Abbreviations: CI-IXT, convergence insufficiency intermittent exotropia; D, diopter.
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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.
Procedure: S-BLR
For C-BLR, the LR is recessed based on distant exodeviation.
Procedure: C-BLR
Surgery of slanted bilateral LR recession for CI-IXT patients
Surgery of conventional bilateral lateral rectus recession for CI-IXT patients
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.
Time frame: at 12 month
suboptimal surgical rate
suboptimal surgical cases/total cases. Suboptimal surgical outcomes include: undercorrection, overcorrection, diplopia, torsional deviation, A-V pattern, abduction limitation and reoperation.
Time frame: at 12 month
Plan to share: No — We concerns about patient privacy issues and it's better to protect the publication potential.
Ran from Oct 2019 to primary completion in Feb 2022, 28 months.
Of 29 interventional studies with no phase under Exotropia, half reached primary completion within 17 months of starting (the median), counting those still running; a quarter within 11 and three quarters within 46. This study's 28 months is above that.
How these figures are worked out, and which studies are left out of them.
This study is completed, as verified in Dec 2023. You cannot join it, but the record below documents what was studied.
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