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Intervention Review

Interventions for intermittent exotropia

  1. Sarah R Hatt1,*,
  2. Lawrence Gnanaraj2

Editorial Group: Cochrane Eyes and Vision Group

Published Online: 19 JUL 2006

Assessed as up-to-date: 24 NOV 2008

DOI: 10.1002/14651858.CD003737.pub2

How to Cite

Hatt SR, Gnanaraj L. Interventions for intermittent exotropia. Cochrane Database of Systematic Reviews 2006, Issue 3. Art. No.: CD003737. DOI: 10.1002/14651858.CD003737.pub2.

Author Information

  1. 1

    Mayo Clinic, Ophthalmology Research, Rochester, USA

  2. 2

    Sunderland Eye Infirmary, Sunderland, UK

*Sarah R Hatt, Ophthalmology Research, Mayo Clinic, Guggenheim 9, 200 1st St. SW, Rochester, MN 55905, USA.

Publication History

  1. Publication Status: New search for studies and content updated (no change to conclusions)
  2. Published Online: 19 JUL 2006


This is not the most recent version of the article. View current version (31 MAY 2013)



  1. Top of page
  2. Abstract
  3. Plain language summary
  4. 摘要


The clinical management of intermittent exotropia has been discussed extensively in the literature, yet there remains a lack of clarity regarding indications for intervention, the most effective form of treatment and whether or not there is an optimal time in the evolution of the disease at which any treatment should be carried out.


The objective of this review was to analyse the effects of various surgical and non-surgical treatments in randomised trials of participants with intermittent exotropia, to report intervention criteria and determine the significance of factors such as age with respect to outcome.

Search methods

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library, Issue 4, 2008), MEDLINE (January 1966 to November 2008), EMBASE (January 1980 to November 2008), the UK Clinical Trials Gateway (UKCTG) and Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to November 2008). No language or date restrictions were placed on the searches. The electronic databases were last searched on 25 November 2008. We manually searched the British Orthoptic Journal, proceedings of the European Strabismological Association (ESA), International Strabismological Association (ISA) and American Academy of Paediatric Ophthalmology and Strabismus meeting (AAPOS). We contacted researchers who are active in the field for information about further published or unpublished studies.

Selection criteria

We included randomised controlled trials of any surgical or non-surgical treatment for intermittent exotropia.

Data collection and analysis

Each review author independently assessed study abstracts identified from the electronic and manual searches. Author analysis was then compared and full papers for appropriate studies were obtained.

Main results

We found one randomised trial that was eligible for inclusion. This trial showed that unilateral surgery was more effective than bilateral surgery for correcting the basic type of intermittent exotropia.

Authors' conclusions

The available literature consists mainly of retrospective case reviews which are difficult to reliably interpret and analyse. The one randomised trial included found unilateral surgery more effective than bilateral surgery for basic intermittent exotropia. However, across all identified studies, measures of severity and thus criteria for intervention are poorly validated, and there appear to be no reliable natural history data. There is therefore a pressing need for improved measures of severity, a better understanding of the natural history and carefully planned clinical trials of treatment to improve the evidence base for the management of this condition.


Plain language summary

  1. Top of page
  2. Abstract
  3. Plain language summary
  4. 摘要

Treatment for a type of childhood strabismus where one or both eyes intermittently turn outwards

Strabismus is a condition in which the eyes are out of alignment, that is one eye looks straight ahead whilst the other eye turns inwards, outwards, up or down. In most cases of childhood onset strabismus the misalignment is present constantly, but in intermittent exotropia (X(T)) an eye intermittently drifts outwards (exotropia), typically more so when looking into the distance, when tired or day-dreaming. When the child focuses on something close, the eye usually moves back to the centre. In X(T) ability to use the eyes together as a pair (binocular single vision) is typically retained during periods when the exotropia is controlled and the image from one eye is switched off or 'suppressed' when the exotropia occurs. Treatment for X(T) may be sought to improve the appearance of misalignment or may be instigated if there is concern that it is worsening with potential or actual loss of binocular single vision. Treatment typically consists of surgery on the muscles around the eye: it may be either on the outside muscle of both eyes or on the inside and outside muscle of one eye. Exercises to strengthen the muscles may sometimes be used; sometimes patching or glasses for short/ near sightedness can be tried. There is currently not a clear understanding of which treatments work most effectively and at what point any treatment should be given. We searched for studies where participants with X(T) had been randomised to receive treatment. The aim was to establish which treatments are most effective at correcting the exotropia without adversely affecting any pre-existing binocular single vision. The one included study in this review compared surgery on one eye to surgery on both eyes for the basic type of X(T) and found that surgery on one eye was more effective. There are many studies of X(T) in the current literature but the methods used do not allow reliable interpretation of the results. Furthermore there is a worrying lack of evidence regarding the natural history of X(T) and poor validation of measures of severity. There is a clear need for further randomised studies to provide more reliable evidence for the management of this condition.



  1. Top of page
  2. Abstract
  3. Plain language summary
  4. 摘要


對於間歇性外斜視(intermittent exotropia)的介入措施





我們檢索考科藍圖書館的the Cochrane Central Register of Controlled Trials  CENTRAL (其包含the Cochrane Eyes and Vision Group Trials Register)(2006年,第1期),MEDLINE (1966至2006年3月), EMBASE (1980至2006年3月),National Research Register (2006年,第1期),PubMed (於2006年3月13日檢索;持續90天)及LILACS (Latin American and Caribbean Literature on Health Sciences) (1966至2002年)。我們人工檢索the British Orthoptic Journal,the European Strabismological Association (ESA)的會議報告,International Strabismological Association (ISA)及American Academy of Paediatric Ophthalmology and Strabismus meeting (AAPOS)。我們聯絡該領域專業的研究人員以取得進一步發表或未發表研究的資訊。人工或電子資料庫的檢索策略不限制語言。











此翻譯計畫由臺灣國家衛生研究院(National Health Research Institutes, Taiwan)統籌。