Advertisement

Topics

Observation Versus Occlusion Therapy for Intermittent Exotropia

2014-07-24 14:10:36 | BioPortfolio

Summary

The present study is being conducted to assess the natural history of intermittent exotropia and to establish the effectiveness of occlusion in its treatment.

Study Objectives:

- To determine the effectiveness of occlusion for the treatment of intermittent exotropia among patients aged 3 to < 11 years who have baseline near stereoacuity of 400 arcsec or better by Preschool Randot stereotest

- To determine the natural history of intermittent exotropia among patients aged 3 to < 11 years who have baseline near stereoacuity of 400 arcsec or better by Preschool Randot stereotest

Description

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 in the distance but may also be present at near. Many cases of IXT are treated using non-surgical interventions, such as part-time occlusion, fusional vergence exercises, and over-minus lenses. The rationale for such interventions is that they may improve the ability to control the IXT and preserve stereoacuity, thereby potentially addressing both visual function and social concerns, and may delay or eliminate the need for surgical correction of IXT. Nevertheless, the natural history of IXT is unknown and in many cases it is not known whether withholding treatment may in fact allow for spontaneous resolution or improvement in IXT, making non-surgical or surgical intervention unnecessary. Moreover, although non-surgical treatments for IXT are commonly prescribed, such treatments have not been subjected to rigorous study and their efficacy in improving visual function or social concerns remains unclear.

One aim of the present study is to better understand the natural history of IXT. Available reports on the natural history of IXT disagree on the progression of the disease. A 1966 study by von Noorden (cited in von Noorden and Campos) found that over an average of 3.5 years of follow-up, 75% of 51 patients showed signs of IXT progression, 9% showed no change, and 16% improved without therapy. A 1968 retrospective study by Hiles et al found that after a minimum of 6 years follow up with observation and nonsurgical treatment, 81% of 48 patients showed no change in angle of deviation. The results of more recent retrospective studies show some reporting that the majority of cases improve over time, others reporting that most cases remain stable, and still others reporting that most cases deteriorate. It is therefore unclear what proportion of patients, if left untreated, is likely to deteriorate, improve, or remain stable over time. Natural history data acquired during this study will help determine not only what proportion of patients change over time, but whether there are associated prognostic indicators of deterioration or improvement. Such data will not only enable better identification of those patients with IXT likely to benefit from treatment and those for whom treatment is likely to be unnecessary, but will also improve the quality of medical advice to parents regarding the likely progression of the disease, thus alleviating anxiety.

The aim of most forms of non-surgical treatments for IXT is to improve the strength and/or quality of binocular single vision by either eliminating suppression, increasing awareness of diplopia, and/or increasing positive fusional amplitudes. Commonly used non-surgical treatment methods include: occlusion, fusional vergence exercises (sometimes known as vision therapy or orthoptics), and over-minus lenses. When surveyed in 1990, members of the American Association for Pediatric Ophthalmology and Strabismus reported that occlusion was the most commonly used form of non-surgical treatment. More recently (2008), a poll of our investigator group revealed again that occlusion was the most widely prescribed non-surgical treatment for children affected by IXT.

Occlusion is thought to work by interrupting the development of or eliminating already present suppression, an adaptation to avoid diplopia in IXT. Persistent or entrenched suppression prevents normal binocular vision and may lead to permanent loss of stereoacuity. If successful, occlusion may then result in improved binocular sensory fusion.

As reported in recent reviews of treatment for IXT, previous studies of occlusion vary regarding the recommended occlusion dose (from 3 hours a day to full time), the optimum duration of occlusion treatment (from 6 weeks to 42 months), and which eye should be occluded (preferred/dominant eye or alternate eyes). For the majority of studies, part-time occlusion, rather than full-time occlusion was preferred. In the three occlusion studies conducted prospectively, the recommended dose was either 3 hours a day, 3 to 6 hours a day, or 4 to 6 hours a day, and the duration of occlusion ranged from 3 months to 6 months to up to 42 (mean 15) months. Nevertheless, these previous studies of occlusion for the treatment of IXT used a variety of outcome measures at a variety of non-standardized time points; therefore, no definite conclusions can be drawn from the existing literature.

Although occlusion treatment for IXT treatment is widely used, there have been no randomized clinical trials evaluating its effectiveness. Understanding the degree of effectiveness of occlusion treatment for IXT and the natural history of IXT has important public health implications. Successful restoration of binocular alignment and normal binocular function with occlusion therapy, or spontaneous improvement, will reduce the proportion of children undergoing surgery. Defining the rate of success with either occlusion or observation is therefore important in planning treatment for children with IXT. Alternatively, evidence of low treatment effectiveness with occlusion will help avoid unnecessary treatment.

The present study is being conducted to assess the natural history of IXT and to establish the effectiveness of occlusion in its treatment.

Study Design

Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Single Blind (Outcomes Assessor), Primary Purpose: Treatment

Conditions

Exotropia

Intervention

occlusion treatment

Location

Southern California College of Optometry
Fullerton
California
United States
92831-1699

Status

Recruiting

Source

Jaeb Center for Health Research

Results (where available)

View Results

Links

Published on BioPortfolio: 2014-07-24T14:10:36-0400

Clinical Trials [248 Associated Clinical Trials listed on BioPortfolio]

Part-time Patch Therapy for Treatment of Intermittent Exotropia

Intermittent exotropia is the most common type of exotropia in children. Treatment options are surgical and non surgical. Nonsurgical management include Correction of refractive errors, Ac...

Study of Non-surgical Treatment Versus Observation in Asian Children With Intermittent Exotropia

Non-surgical treatment (ie. patching or fusion exercises) of intermittent exotropia may help in increasing control of strabismus

The Effect of Oculo-Motor Exercises in Intermittent Exotropia

In childhood strabismus, exotropia is most frequently seen with intermittent exotropia and convergence failure in the first decade of life. This situation adversely affects children's psyc...

Office Based Vergence and Accommodative Therapy and Intermittent Exotropia

This pilot study is designed specifically to determine the short-term effect of OBVAT on intermittent exotropia in terms of 4 key areas (Standardizing reported outcomes of surgery for inte...

Protective Effect of Biodegradable Collagen Implant (Ologen) in Scleral Thinning After Strabismus Surgery

This study is to investigate protective effect of biodegradable collagen implant in scleral showing after lateral rectus recession in patients with exotropia.

PubMed Articles [16619 Associated PubMed Articles listed on BioPortfolio]

Postoperative changes of intermittent exotropia type as classified by 1-hour monocular occlusion.

To evaluate postoperative changes of the intermittent exotropia type as classified by 1-hour monocular occlusion test.

A Randomized Trial Comparing Bilateral Lateral Rectus Recession versus Unilateral Recess-Resect for Basic-Type Intermittent Exotropia.

To compare long-term outcomes after bilateral lateral rectus recession (BLRc) or unilateral recess-resect (R&R) for primary treatment of childhood intermittent exotropia (IXT).

Bilateral Lateral Rectus Recession for the Treatment of Recurrent Exotropia after Bilateral Medial Rectus Resection.

To evaluate the efficacy of bilateral lateral rectus muscle recession (BLR) to treat recurrent exotropia after bilateral medial rectus muscle resection (BMR).

The results of cephalometric analysis in the dynamics of orthodontic treatment of patients with transversal anomalies of occlusion.

Introduction: This article discusses the problems of the current issue of modern orthodontics aimed at increasing the effectiveness of diagnosis and treatment of transversal anomalies of occlusion in ...

Comparison of plication and resection in large-angle exotropia.

Plication of the rectus muscles used sparingly as a tightening procedure compared to resection, yet the relative efficacy of these procedures is difficult to assess because the sparse literature compa...

Medical and Biotech [MESH] Definitions

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.

An occlusion resulting in overstrain and injury to teeth, periodontal tissue, or other oral structures.

The application of LEECHES to the body to draw blood for therapeutic purposes. Such medicinal leeching, an ancient medical practice, is still being used in microsurgery and the treatment of venous congestion or occlusion.

Dental occlusion in which the occlusal contact of the teeth on the working side of the jaw is accompanied by the harmonious contact of the teeth on the opposite (balancing) side. (From Jablonski, Dictionary of Dentistry, 1992, p556)

Procedures, surgery, or other treatment without consent of person or persons receiving treatment.

More From BioPortfolio on "Observation Versus Occlusion Therapy for Intermittent Exotropia"

Advertisement
Quick Search
Advertisement
Advertisement

 

Relevant Topics

Pediatrics
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 ...

Surgical treatments
Surgery is a technology consisting of a physical intervention on tissues. All forms of surgery are considered invasive procedures; so-called "noninvasive surgery" usually refers to an excision that does not penetrate the structure being exci...

Psychiatry
Psychiatry is the study of mental disorders and their diagnosis, management and prevention.  Conditions include schizophrenia, severe depression and panic disorders among others. There are pharmaceutical treatments as well as other therapies to help...


Searches Linking to this Trial