Surgery versus Active Monitoring in Intermittent Exotropia (SamExo): study protocol for a pilot randomised controlled trial

Trials

Michael P Clarke²  Luke Vale⁶  Peter Tiffin¹  Robert Taylor⁵  Nick Steen⁶  John Sloper⁷  Jing Shen⁶  Christine J Powell³  Elaine McColl⁶  Deborah Buck⁴ 

[1] Sunderland Eye Infirmary, Sunderland, UK;Institute of Neuroscience, Medical School, Newcastle University, Newcastle upon Tyne, UK;Royal Victoria Infirmary Eye Department, Newcastle upon Tyne Hospitals NHS Trust, Newcastle upon Tyne, UK;Institute of Neuroscience, c/o Clinical Trials Unit, Medical School, Newcastle University, Newcastle upon Tyne, UK;York Hospitals NHS Trust, York, UK;Institute of Health & Society, Baddiley-Clark Building, Newcastle University, Newcastle upon Tyne, UK;Moorfields Eye Hospital, London, UK

关键词: Qualitative research;    Parents;    Children;    Randomised controlled trial;    Pilot study;    Feasibility studies;    Surgery;    Divergent strabismus;    Intermittent exotropia;   

Others  :  1095262
DOI  :  10.1186/1745-6215-13-192

 received in 2012-05-18, accepted in 2012-09-26,  发布年份 2012

【 摘 要 】

Background

Childhood intermittent exotropia [X(T)] is a type of strabismus (squint) in which one eye deviates outward at times, usually when the child is tired. It may progress to a permanent squint, loss of stereovision and/or amblyopia (reduced vision). Treatment options for X(T) include eye patches, glasses, surgery and active monitoring. There is no consensus regarding how this condition should be managed, and even when surgery is the preferred option clinicians disagree as to the optimal timing. Reports on the natural history of X(T) are limited, and there is no randomised controlled trial (RCT) evidence on the effectiveness or efficiency of surgery compared with active monitoring. The SamExo (Surgery versus Active Monitoring in Intermittent Exotropia) pilot study has been designed to test the feasibility of such a trial in the UK.

Methods

Design: an external pilot patient randomised controlled trial.

Setting: four UK secondary ophthalmology care facilities at Newcastle NHS Hospitals Foundation Trust, Sunderland Eye Infirmary, Moorfields Eye Hospital and York NHS Trust.

Participants: children aged between 6 months and 16 years referred with suspected and subsequently diagnosed X(T). Recruitment target is a total of 144 children over a 9-month period, with 120 retained by 9-month outcome visit.

Randomisation: permuted blocks stratified by collaborating centre, age and severity of X(T).

Interventions: initial clinical assessment; randomisation (eye muscle surgery or active monitoring); 3-, 6- and 9-month (primary outcome) clinical assessments; participant/proxy completed questionnaire covering time and travel costs, health services use and quality of life (Intermittent Exotropia Questionnaire); qualitative interviews with parents to establish reasons for agreeing or declining participation in the pilot trial.

Outcomes: recruitment and retention rates; nature and extent of participation bias; nature and extent of biases arising from crossover or loss to follow-up; reasons for agreeing/declining participation; variability of cure rates (to inform power calculations for a definitive RCT); completion rates of outcome measures.

Discussion

The SamExo pilot trial will provide important pointers regarding the feasibility of a full RCT of immediate surgery versus deferred surgery/active monitoring. The results of this pilot, including differences in cure rates, will inform the design of a definitive RCT.

Trial registration

ISRCTN44114892

【 授权许可】

   
2012 Buck et al.; licensee BioMed Central Ltd.

【 图 表 】

Figure 1.

Figure 2.

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