Track topics on Twitter Track topics that are important to you
The purpose of this study is to evaluate the effectiveness of bilateral lateral rectus muscle recession versus unilateral lateral rectus recession with medial rectus resection procedures for the treatment of basic type and pseudo divergence excess type intermittent exotropia.
Intermittent exotropia (IXT) is the most common form of childhood onset exotropia with an incidence of 32.1 per 100,000 in children under 19 years of age. Intermittent exotropia is characterized by an exotropia that is not constant and is mainly present when viewing at distance, but may also be present at near. Normal binocular single vision (BSV) is typically present at near when the exotropia is controlled, with evidence of normal (occasionally sub-normal) stereoacuity. Although the natural history of the condition is largely unknown, many children with IXT are treated using either surgical or non-surgical interventions. The rationale for intervention in childhood IXT is that extended periods of misalignment may lead to entrenched suppression, resulting in loss of BSV. Intervention may also aim to address the social effects caused by the appearance of misaligned eyes. Many children treated for IXT are currently treated surgically.
There is poor agreement as to which type of surgery is most effective for the correction of IXT and the debate has long been related to differentiation between IXT sub-types. Based on distance-near angle disparity, IXT sub-types are classified as: 1) basic (similar magnitude of misalignment at distance and near); 2) true divergence excess (larger at distance); 3) pseudo divergence excess (initially larger at distance, but near angle increases following occlusion or with addition of plus lenses at near); 4) convergence insufficiency (larger at near). Basic and pseudo divergence excess appear to be the most common of the sub-types, and are also the types for which there is most disagreement regarding the optimum surgical approach. The two most common procedures are bilateral lateral rectus recession (BLRrec) and unilateral lateral rectus recession combined with a medial rectus resection in the same eye (R&R). Traditionally, BLRrec has been advocated where there is a larger distance angle, and R&R where there is a similar angle at distance and near. A survey of American strabismus surgeons published in 1990 found that the majority performed BLRrec for both basic and divergence excess types. Similarly, we found by polling our investigator group that the majority still perform a BLRrec for basic type IXT. Nevertheless, controversy still exists as to which of these surgical approaches is superior. Advocates of the BLRrec procedure tend to hold that surgery should be based purely on the distance angle of deviation. Proponents of R&R surgery suggest resection of the medial rectus best addresses the exodeviation at near.
The proposed advantage of the R&R procedure is that resecting the medial rectus, with a possible longer term initial overcorrection, is necessary for a stable and superior long-term outcome. Nevertheless, those who favor the BLRrec procedure suggest that the more profound and prolonged initial overcorrection occurring with R&R is not only unnecessary, but may in fact be harmful. A persistent overcorrection may be associated with the development of diplopia, amblyopia, and loss of stereoacuity. On the other hand, critics of the BLRrec procedure suggest that long-term recurrence rates are higher. Poor motor outcomes are likely to require reoperation and therefore the long-term success rates of these surgeries have public health importance in terms of cost to society.
Evaluating initial and long-term surgical outcomes in the proposed RCT will answer questions regarding the failure rates of these surgeries and also provide needed data on the potential harm of each procedure.
Only one prospective randomized clinical trial addresses success rates of BLRrec versus R&R for IXT. After between 12-15 months of follow up, 82% of 17 patients undergoing an R&R had a satisfactory outcome compared to 52% of 19 patients undergoing a BLRrec. Nevertheless, there are some important limitations of this previous study. The sample size was very small. The study population was a sub-group of patients with basic type IXT, excluding patients with basic IXT whose angle of deviation increased at far distance or following occlusion, thus limiting the generalizability of the results. In addition, outcomes were assessed unmasked, potentially biasing the results. One observational study of 103 patients (90% of whom had basic type IXT) found 1-year success rates of 56% for BLRrec and 60% for R&R. A retrospective study of 115 patients with basic type IXT reported success rates of 69% for BLRrec and 77% for R&R after an average of 15 months of follow up. Other studies comparing surgery types are limited not only by retrospective study design but also by inclusion of other types of exotropia, making it difficult to interpret results. In addition, many different criteria for success are used, precluding meaningful comparison of success rates between studies. This lack of evidence makes it very difficult to counsel parents of children with IXT regarding the likely success and complication rate of either procedure, limiting our ability to make informed management decisions. Establishing the respective failure rates through the proposed study will allow physicians to offer patients the type of surgery with the highest chance of long-term success, minimizing suboptimal results and repeat surgeries.
The present study is being conducted to compare the effectiveness of BLRrec with R&R for the surgical treatment of basic type and pseudo divergence excess type IXT.
Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Single Blind (Outcomes Assessor), Primary Purpose: Treatment
Bilateral lateral rectus recession (BLRrec), Unilateral lateral rectus recession with medial rectus resection (R&R)
Vanderbilt Children's Hospital
Jaeb Center for Health Research
Published on BioPortfolio: 2014-07-23T21:11:22-0400
- Background and study aims : The investigators conducted this study to compare the movement of extraocular muscle after two types of recession surgery with non-invasive tool ca...
This study is to investigate protective effect of biodegradable collagen implant in scleral showing after lateral rectus recession in patients with exotropia.
Suture reapproximation of the rectus muscles at primary cesarean delivery is a common practice about which there are no data. Some Obstetricians believe that suture reapproximation of the ...
This is a prospective, double-blinded, randomized controlled study comparing the efficacy of trans-incisional rectus sheath block to laparoscopic guided rectus sheath block for pediatric s...
This is a prospective randomised controlled trial that will compare the outcomes of rectus sheath catheters to epidurals in patients who have undergone a cystectomy, via a lower midline ab...
Morphology of the extraocular muscles plays an important role in many ophthalmological surgeries and diagnostic imaging studies. Detailed understanding of length, width, point of insertion and the rel...
The aims of this study were to elucidate the detailed anatomy of the abducens nerve in the lateral rectus muscle (LRM) and the intramuscular innervation pattern using Sihler staining.
PurposeThe aim of this study is to assess the importance of magnetic resonance imaging (MRI) before surgery in highly myopic patients, evaluating the capability of imaging to identify muscles displace...
A 53-year-old man with hyperthyroidism presented with asymmetric proptosis and diplopia. Thyroid-stimulating immunoglobulin was elevated, suggesting active thyroid eye disease. Imaging of the orbits r...
Plasmacytoma is an uncommon presentation of plasma cell malignancy, especially in the absence of multiple myeloma. Orbital plasmacytomas generally originate from bone, although few cases in the litera...
The muscles that move the eye. Included in this group are the medial rectus, lateral rectus, superior rectus, inferior rectus, inferior oblique, superior oblique, musculus orbitalis, and levator palpebrae superioris.
A form of ocular misalignment where the visual axes diverge inappropriately. For example, medial rectus muscle weakness may produce this condition as the affected eye will deviate laterally upon attempted forward gaze. An exotropia occurs due to the relatively unopposed force exerted on the eye by the lateral rectus muscle, which pulls the eye in an outward direction.
A form of ocular misalignment characterized by an excessive convergence of the visual axes, resulting in a "cross-eye" appearance. An example of this condition occurs when paralysis of the lateral rectus muscle causes an abnormal inward deviation of one eye on attempted gaze.
Diseases of the oculomotor nerve or nucleus that result in weakness or paralysis of the superior rectus, inferior rectus, medial rectus, inferior oblique, or levator palpebrae muscles, or impaired parasympathetic innervation to the pupil. With a complete oculomotor palsy, the eyelid will be paralyzed, the eye will be in an abducted and inferior position, and the pupil will be markedly dilated. Commonly associated conditions include neoplasms, CRANIOCEREBRAL TRAUMA, ischemia (especially in association with DIABETES MELLITUS), and aneurysmal compression. (From Adams et al., Principles of Neurology, 6th ed, p270)
The 6th cranial nerve. The abducens nerve originates in the abducens nucleus of the pons and sends motor fibers to the lateral rectus muscles of the eye. Damage to the nerve or its nucleus disrupts horizontal eye movement control.
Arthritis Fibromyalgia Gout Lupus Rheumatic Rheumatology is the medical specialty concerned with the diagnosis and management of disease involving joints, tendons, muscles, ligaments and associated structures (Oxford Medical Diction...
Pediatrics is the general medicine of childhood. Because of the developmental processes (psychological and physical) of childhood, the involvement of parents, and the social management of conditions at home and at school, pediatrics is a specialty. With ...
eye muscle resection vs recessionBilateral lateral rectus muscle recessionrectus resectionrecess of right superior rectus muscletreatment for bilateral lateral rectiweaknessrecess rectuswhat is rectus recession repairlateral rectus resectionbilateral lateral rectus resectionbilateral rectus resection