ExotropiaNCT06084442
Evaluation of The Techniques in Correcting Large-Angle Exotropia
A study testing Evaluation of The Techniques of Lateral Rectus Muscle Combined Recession with Hang Back and Combined Recession with Z-Tenotomy in Correcting Large-Angle Exotropia in people with Exotropia and Evaluation of Surgical Techniques in Correcting Exotropia, run by Tanta University.
Trial summary
The aim of this study is to evaluate the techniques of combined lateral rectus muscle recession with hang back and combined lateral rectus muscle recession with z-tenotomy in correcting large-angle exotropia. Read more about this study
- Who is it for?
- Any age
- Conditions the study is for
- Exotropia, Evaluation of Surgical Techniques in Correcting Exotropia
- What is being tested?
- Evaluation of The Techniques of Lateral Rectus Muscle Combined Recession with Hang Back and Combined Recession with Z-Tenotomy in Correcting Large-Angle Exotropia
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 50 participants
- Where
- No sites listed yet
- Study dates
- Oct 2023to Apr 2024
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages Any age
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Who may be able to join
- Patients suffering from large angle exotropia; defined, in this study, as an angle of deviation ≥ 40 prism diopters (PD).
Who cannot join
- Patients suffering from exotropia with angle < 40 prism diopters (PD).
- Patient with paralytic strabismus.
- Patient with restrictive strabismus.
- Patient with combined vertical and horizontal deviation.
- Patients with previous strabismus surgery.
- Patients who had previously been administered botulinum toxin A.
- Patient refusal.
Trial locations and contacts
No sites are listed yet.
About this study
Official title: Evaluation of The Techniques of Lateral Rectus Muscle Combined Recession With Hang Back and Combined Recession With Z-Tenotomy in Correcting Large-Angle Exotropia
The aim of this study is to evaluate the techniques of combined lateral rectus muscle recession with hang back and combined lateral rectus muscle recession with z-tenotomy in correcting large-angle exotropia.
Read the detailed description
Strabismus was defined as any heterotropia at near or distance fixation, or both, on cover testing. Micro strabismus was known as a deviation of fewer than 10 prism diopters (PD). Different studies have defined large angle deviation as 35 Δ , 40 Δ, 50 Δ and 60 Δ.
Studies revealed that during the first decade of life, exotropia is most prevalent with intermittent exotropia and convergence insufficiency are the most frequent. Exotropic deviations include exophoria, infantile exotropia, intermittent exotropia, sensory exotropia and consecutive exotropia.
Large-angle constant exotropia has a negative impact on the patients and surgical treatment of exodeviations improves the patient's psychosocial functioning. Hence, many surgical techniques have been described for management of exotropia, including bilateral lateral rectus recessions or recess/resect procedures. Botulinum toxin injection combined with recession-resection procedures was used as another surgical technique.
As a fact large-angle exotropia usually requires greater amounts of surgery, often a surgery on a greater number of extraocular muscles. Hence, 3 or 4 horizontal muscle surgery was performed for correcting large angle exotropia. Single-staged three horizontal muscles surgery for large angle intermittent exotropia has been more successful.
Recently, medial rectus muscle surgery as bilateral medial rectus resection for primary large-angle exotropia has been used with successful results. A successful outcome of surgery was defined as deviation within 10 prism diopters for both distance and near.
Moreover, hang-back loop suspension surgical technique can be performed for lateral rectus (LR) muscle recession. This technique can offer potential advantages over the conventional rectus muscle recession, including better exposure of the site of scleral sutures, lower risk of scleral perforation , shorter procedure duration and lower postoperative induced astigmatism.
On the other hand, the hang-back recession has some limitations as a potential unpredictability in surgical outcomes.Although previous reports suggest that the hang-back technique for LR recession for exotropia results in poorer surgical success and may require a different surgical dosage, another study proved that the hang-back surgical technique was as effective as conventional LR recession surgery for children with exotropia.
Furthermore, many studies were performed on Z-tenotomy technique as an alternative procedure for muscle weakening. This technique was applied for superior oblique muscle in cases with mild to moderate over depression in adduction with success rate 90%. An Other study has revealed that z-tenotomy up to 50% progressively reduces extraocular tendon force transmission, but Z-tenotomy of ≥50% is biomechanically equivalent in vitro to complete tenotomy.
In the past it was thought that muscle recessions with the muscle placed behind the anatomical equator of the globe would cause limitation of ocular rotation. Postoperative abduction limitation is one of the main problems in large recession and/or resection for primary and recurrent exotropia with large angle. It is generally thought that keeping the lateral rectus recession to no more than 8 mm prevents this complication. However, several studies revealed that large amounts of recession can be done without causing significant ocular movement limitation.
- Being tested
- Evaluation of The Techniques of Lateral Rectus Muscle Combined Recession with Hang Back and Combined Recession with Z-Tenotomy in Correcting Large-Angle Exotropia
- Medical subject headings
- Exotropia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Evaluation of The Techniques of Lateral Rectus Muscle Combined Recession with Hang Back and Combined Recession with Z-Tenotomy in Correcting Large-Angle ExotropiaProcedure or surgery
Patients will be divided into 2 groups:
- Group (A): Patients will undergo combined LR recession 7mm and hang back technique.
- Group (B): Patients will undergo combined LR recession 7mm and Z-tenotomy technique.
| Study group | Role | What they receive |
|---|---|---|
| combined lateral rectus muscle recession 7mm and hang back technique. | Active comparator | The technique of combined LR recession 7mm and hang back technique:
A. The muscle is exposed in the usual manner and locking suture is passed through full thickness of the LR muscle using nonabsorbable ethibond suture.
B. The muscle is cut from its insertion site. C. Marking the sclera for the rectus muscle recession. a Measurement from the limbus, or b measurement from the original insertion site.
D. Passage of the needles in the sclera using the "crossed swords" Technique E. The muscle has been pulled up to its new insertion point and the sutures have been tied and cut and the remainder of the procedure is identical to the standard hang-back method.
The Receives: Procedure: Evaluation of The Techniques of Lateral Rectus Muscle Combined Recession with Hang Back and Combined Recession with Z-Tenotomy in Correcting Large-Angle Exotropia |
| combined lateral rectus muscle recession 7mm and Z- tenotomy technique. | Active comparator | The technique of lateral rectus muscle Z-tenotomy:
A. The muscle is exposed in the usual manner and two hemostats are each placed 80% of the way across the muscle (or tendon) from opposite borders. The hemostats are placed 3 or 4 mm apart.
B. The posterior hemostat is removed, and scissors are used to cut across the muscle in the crushed area. By cutting the muscle in the crushed area, bleeding is kept to a minimum.
C. The hemostat nearer the insertion is removed, and the muscle is cut along the crushed area using small snips with scissors.
D. lengthening of the muscle will occur. Any bleeding is controlled with pressure.
E. After the distal myotomy has been performed, in a very tight muscle, a No. 15 Bard Parker blade can be used to divide the tendon fibers, cutting against the muscle hook. This can be accomplished with a scraping motion with the knife blade at nearly right angles to avoid scleral perforation. Receives: Procedure: Evaluation of The Techniques of Lateral Rectus Muscle Combined Recession with Hang Back and Combined Recession with Z-Tenotomy in Correcting Large-Angle Exotropia |
What is being measured
The primary outcome is the main question the study is designed to answer.
sucessful alignment
Successful motor alignment will be defined as orthotropia or ≤ 10 Δ Exotropia or Esotropia at 6 m distance with spectacle correction worn at 6 months. Successful sensory alignment will be by achievement of fusion and moderate or good stereoacuity postoperatively.
Measured: Follow up period of 6 month from the time of initial surgery. All patients will be examined at one week, one month, 3 month and 6 months.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted16 Oct 2023
- Study startOct 2023 (estimated)
- Primary completionMar 2024 (estimated)
- Study completionApr 2024 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (6)Papers the sponsor has linked to this study.
- Other trials for ExotropiaStudies of the same condition, open and under way.
- More trials run by Tanta UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Patients will be divided into 2 groups: * Group (A): Patients will undergo combined LR recession 7mm and hang back technique. * Group (B): Patients will undergo combined LR recession 7mm and Z-tenotomy technique.
- Masking
- None (open label)
- Enrolment
- 50 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Tanta University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Basma Gamal Mohamed Ahmed Sayed Ahmed, Tanta University
- Investigators
- El-Sayed Samir Arafa, MD, Study director, Tanta UniversityAmr Mahmoud Awara, MD, Study director, Tanta UniversityHeba Mohamed Shafik, MD, Study director, Tanta University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06084442
- Sponsor's protocol ID
- Large-Angle Exotropia
- Status last verified
- Oct 2023
- First submitted
- 9 Oct 2023
- Last updated
- 16 Oct 2023
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Publications
Livir-Rallatos G, Gunton KB, Calhoun JH. Surgical results in large-angle exotropia. J AAPOS. 2002 Apr;6(2):77-80. doi: 10.1067/mpa.2002.122059.
PubMed 11997802Chen JH, Morrison DG, Donahue SP. Three and Four Horizontal Muscle Surgery for Large Angle Exotropia. J Pediatr Ophthalmol Strabismus. 2015 Sep-Oct;52(5):305-10. doi: 10.3928/01913913-20150609-02. Epub 2015 Jun 15.
PubMed 26098544Chung AK, Rehman SU, Bradbury JA. Comparison of modified anchored "hang-back technique (HBT)" with conventional HBT in bimedial rectus recession. J AAPOS. 2005 Jun;9(3):234-9. doi: 10.1016/j.jaapos.2005.02.011.
PubMed 15956942Betts C, Olitsky S. Corneal astigmatic effects of conventional recession vs suspension recession ("hang-back") strabismus surgery: a pilot study. Binocul Vis Strabismus Q. 2006;21(4):211-3.
PubMed 17069557Orlin A, Mills M, Ying GS, Liu C. A comparison of hang-back with conventional recession surgery for exotropia. J AAPOS. 2007 Dec;11(6):597-600. doi: 10.1016/j.jaapos.2007.06.001. Epub 2007 Oct 24.
PubMed 17920319Shin A, Yoo L, Demer JL. Biomechanics of superior oblique Z-tenotomy. J AAPOS. 2013 Dec;17(6):612-7. doi: 10.1016/j.jaapos.2013.09.004.
PubMed 24321425
Study at a glance
From the registry record, last updated by the sponsor on 16 Oct 2023. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Evaluation of The Techniques of Lateral Rectus Muscle Combined Recession With Hang Back and Combined Recession With Z-Tenotomy in Correcting Large-Angle Exotropia
- ClinicalTrials.gov ID
- NCT06084442
- Acronym / sponsor ID
- Large-Angle Exotropia
- Study type
- Interventional
- Recruitment status
- Unknown status
- Enrolment
- 50 participants (estimated)
- Lead sponsor
- Tanta UniversityUniversity, hospital or other
- Study start
- Oct 2023 (estimated)
- Primary completion
- Mar 2024 (estimated)
- Study completion
- Apr 2024 (estimated)
- First posted
- 16 Oct 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The aim of this study is to evaluate the techniques of combined lateral rectus muscle recession with hang back and combined lateral rectus muscle recession with z-tenotomy in correcting large-angle exotropia.
Detailed description
Strabismus was defined as any heterotropia at near or distance fixation, or both, on cover testing. Micro strabismus was known as a deviation of fewer than 10 prism diopters (PD). Different studies have defined large angle deviation as 35 Δ , 40 Δ, 50 Δ and 60 Δ.
Studies revealed that during the first decade of life, exotropia is most prevalent with intermittent exotropia and convergence insufficiency are the most frequent. Exotropic deviations include exophoria, infantile exotropia, intermittent exotropia, sensory exotropia and consecutive exotropia.
Large-angle constant exotropia has a negative impact on the patients and surgical treatment of exodeviations improves the patient's psychosocial functioning. Hence, many surgical techniques have been described for management of exotropia, including bilateral lateral rectus recessions or recess/resect procedures. Botulinum toxin injection combined with recession-resection procedures was used as another surgical technique.
As a fact large-angle exotropia usually requires greater amounts of surgery, often a surgery on a greater number of extraocular muscles. Hence, 3 or 4 horizontal muscle surgery was performed for correcting large angle exotropia. Single-staged three horizontal muscles surgery for large angle intermittent exotropia has been more successful.
Recently, medial rectus muscle surgery as bilateral medial rectus resection for primary large-angle exotropia has been used with successful results. A successful outcome of surgery was defined as deviation within 10 prism diopters for both distance and near.
Moreover, hang-back loop suspension surgical technique can be performed for lateral rectus (LR) muscle recession. This technique can offer potential advantages over the conventional rectus muscle recession, including better exposure of the site of scleral sutures, lower risk of scleral perforation , shorter procedure duration and lower postoperative induced astigmatism.
On the other hand, the hang-back recession has some limitations as a potential unpredictability in surgical outcomes.Although previous reports suggest that the hang-back technique for LR recession for exotropia results in poorer surgical success and may require a different surgical dosage, another study proved that the hang-back surgical technique was as effective as conventional LR recession surgery for children with exotropia.
Furthermore, many studies were performed on Z-tenotomy technique as an alternative procedure for muscle weakening. This technique was applied for superior oblique muscle in cases with mild to moderate over depression in adduction with success rate 90%. An Other study has revealed that z-tenotomy up to 50% progressively reduces extraocular tendon force transmission, but Z-tenotomy of ≥50% is biomechanically equivalent in vitro to complete tenotomy.
In the past it was thought that muscle recessions with the muscle placed behind the anatomical equator of the globe would cause limitation of ocular rotation. Postoperative abduction limitation is one of the main problems in large recession and/or resection for primary and recurrent exotropia with large angle. It is generally thought that keeping the lateral rectus recession to no more than 8 mm prevents this complication. However, several studies revealed that large amounts of recession can be done without causing significant ocular movement limitation.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- Patients will be divided into 2 groups: * Group (A): Patients will undergo combined LR recession 7mm and hang back technique. * Group (B): Patients will undergo combined LR recession 7mm and Z-tenotomy technique.
| Arm | Type | Receives |
|---|---|---|
| combined lateral rectus muscle recession 7mm and hang back technique. | Active comparator | Procedure: Evaluation of The Techniques of Lateral Rectus Muscle Combined Recession with Hang Back and Combined Recession with Z-Tenotomy in Correcting Large-Angle ExotropiaThe technique of combined LR recession 7mm and hang back technique: A. The muscle is exposed in the usual manner and locking suture is passed through full thickness of the LR muscle using nonabsorbable ethibond suture. B. The muscle is cut from its insertion site. C. Marking the sclera for the rectus muscle recession. a Measurement from the limbus, or b measurement from the original insertion site. D. Passage of the needles in the sclera using the "crossed swords" Technique E. The muscle has been pulled up to its new insertion point and the sutures have been tied and cut and the remainder of the procedure is identical to the standard hang-back method. The |
| combined lateral rectus muscle recession 7mm and Z- tenotomy technique. | Active comparator | Procedure: Evaluation of The Techniques of Lateral Rectus Muscle Combined Recession with Hang Back and Combined Recession with Z-Tenotomy in Correcting Large-Angle ExotropiaThe technique of lateral rectus muscle Z-tenotomy: A. The muscle is exposed in the usual manner and two hemostats are each placed 80% of the way across the muscle (or tendon) from opposite borders. The hemostats are placed 3 or 4 mm apart. B. The posterior hemostat is removed, and scissors are used to cut across the muscle in the crushed area. By cutting the muscle in the crushed area, bleeding is kept to a minimum. C. The hemostat nearer the insertion is removed, and the muscle is cut along the crushed area using small snips with scissors. D. lengthening of the muscle will occur. Any bleeding is controlled with pressure. E. After the distal myotomy has been performed, in a very tight muscle, a No. 15 Bard Parker blade can be used to divide the tendon fibers, cutting against the muscle hook. This can be accomplished with a scraping motion with the knife blade at nearly right angles to avoid scleral perforation. |
Who may qualify
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
Key inclusion criteria (1 listed)
- Patients suffering from large angle exotropia; defined, in this study, as an angle of deviation ≥ 40 prism diopters (PD).
Key exclusion criteria (7 listed)
- Patients suffering from exotropia with angle < 40 prism diopters (PD).
- Patient with paralytic strabismus.
- Patient with restrictive strabismus.
- Patient with combined vertical and horizontal deviation.
- Patients with previous strabismus surgery.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Evaluation of The Techniques of Lateral Rectus Muscle Combined Recession with Hang Back and Combined Recession with Z-Tenotomy in Correcting Large-Angle ExotropiaPatients will be divided into 2 groups: * Group (A): Patients will undergo combined LR recession 7mm and hang back technique. * Group (B): Patients will undergo combined LR recession 7mm and Z-tenotomy technique. | Procedure or surgery | combined lateral rectus muscle recession 7mm and Z- tenotomy technique., combined lateral rectus muscle recession 7mm and hang back technique. |
Primary outcome
sucessful alignment
Time frame: Follow up period of 6 month from the time of initial surgery. All patients will be examined at one week, one month, 3 month and 6 months.
Successful motor alignment will be defined as orthotropia or ≤ 10 Δ Exotropia or Esotropia at 6 m distance with spectacle correction worn at 6 months. Successful sensory alignment will be by achievement of fusion and moderate or good stereoacuity postoperatively.
Results and safety
Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 16 Oct 2023.
- Background: PubMed 11997802Livir-Rallatos G, Gunton KB, Calhoun JH. Surgical results in large-angle exotropia. J AAPOS. 2002 Apr;6(2):77-80. doi: 10.1067/mpa.2002.122059.
- Background: PubMed 26098544Chen JH, Morrison DG, Donahue SP. Three and Four Horizontal Muscle Surgery for Large Angle Exotropia. J Pediatr Ophthalmol Strabismus. 2015 Sep-Oct;52(5):305-10. doi: 10.3928/01913913-20150609-02. Epub 2015 Jun 15.
- Background: PubMed 15956942Chung AK, Rehman SU, Bradbury JA. Comparison of modified anchored "hang-back technique (HBT)" with conventional HBT in bimedial rectus recession. J AAPOS. 2005 Jun;9(3):234-9. doi: 10.1016/j.jaapos.2005.02.011.
- Background: PubMed 17069557Betts C, Olitsky S. Corneal astigmatic effects of conventional recession vs suspension recession ("hang-back") strabismus surgery: a pilot study. Binocul Vis Strabismus Q. 2006;21(4):211-3.
- Background: PubMed 17920319Orlin A, Mills M, Ying GS, Liu C. A comparison of hang-back with conventional recession surgery for exotropia. J AAPOS. 2007 Dec;11(6):597-600. doi: 10.1016/j.jaapos.2007.06.001. Epub 2007 Oct 24.
- Background: PubMed 24321425Shin A, Yoo L, Demer JL. Biomechanics of superior oblique Z-tenotomy. J AAPOS. 2013 Dec;17(6):612-7. doi: 10.1016/j.jaapos.2013.09.004.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
El-Sayed Samir Arafa, MD study director
Tanta University
Amr Mahmoud Awara, MD study director
Tanta University
Heba Mohamed Shafik, MD study director
Tanta University
Questions about this trial
What is this clinical trial studying?
A study testing Evaluation of The Techniques of Lateral Rectus Muscle Combined Recession with Hang Back and Combined Recession with Z-Tenotomy in Correcting Large-Angle Exotropia in people with Exotropia and Evaluation of Surgical Techniques in Correcting Exotropia, run by Tanta University.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: status not confirmed, as of the sponsor's last update on 16 Oct 2023. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
Contact Basma Gamal Mohamed Ahmed Sayed Ahmed, Msc (+20 1017954454, basmagamal9090@yahoo.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
sucessful alignment (time frame: Follow up period of 6 month from the time of initial surgery. All patients will be examined at one week, one month, 3 month and 6 months.). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT06084442, which also lists 6 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 16 Oct 2023; AzTrials last refreshed its copy on 2 Nov 2026.