RESUMEN
BACKGROUND: Intermittent exotropia is the most common form of divergent strabismus (squint) in children. Evidence regarding its optimum management is limited. A pilot randomised controlled trial has recently been completed (Surgery versus Active Monitoring in Intermittent Exotropia trial) to determine the feasibility of a full randomised controlled trial. PURPOSE: To identify drivers for and barriers against parents' participation in Surgery versus Active Monitoring in Intermittent Exotropia and to seek their views on information received, the need for randomisation, and enhancing acceptability. METHODS: Multiple method qualitative study using semi-structured telephone interviews to explore parents' motivations and trial screening logs to provide an indication of common barriers. Exploratory thematic analysis identified key themes. RESULTS: A total of 48 interviews were conducted (14 participants; 34 non-participants). Barriers included no desire for surgery/preference to 'wait and see', wanting surgery immediately, feeling uncomfortable about 'surrendering control' over decision-making/being managed 'at random', lack of confidence in the effectiveness of surgery, believing the risks outweighed the benefits, and lack of trust. Drivers included desiring surgery, 'nothing to lose', benefits offsetting the risks, and being in a trial would result in better care. Some also mentioned 'doing their bit' for research. Suggestions for enhancing acceptability included allowing choice of treatment group, giving more time for decision-making, expanding on information given, and improving communication. Many felt the necessity of randomisation was adequately explained, but there was some indication that it was misunderstood. Information extracted from the screening logs of 80/89 eligible non-participants indicated the most prevalent barrier was not wanting surgery/preferring to observe (56%), followed by desiring surgery straightaway (15%). Opposition to randomisation/wanting to retain control was recorded in 9% of cases as was the belief that the child's squint was not severe enough to warrant surgery. LIMITATIONS: Interviews were not audio-recorded. Not all who consented to interview could be contacted, although the response/contact rate was good (48/62). A few parents did not provide reasons for refusing the trial. CONCLUSION: Opposition to surgery and concerns about surrendering control were common obstacles to participation, whereas parents keen for their child to undergo the operation but happy to defer tended to embrace a 'nothing to lose' attitude. Many non-participants would have consented if allowed to choose group, although most of these would have chosen observation. While most parents felt happy with information given and that randomisation was adequately explained, it is of concern that there may be some misunderstanding, which should be addressed in any trial. These findings will inform future trials in childhood exotropia, for example, consideration of preference arms and improving communication. Lessons learnt from the Surgery versus Active Monitoring in Intermittent Exotropia trial could prove valuable to paediatric and surgical trials generally.
Asunto(s)
Actitud Frente a la Salud , Toma de Decisiones , Exotropía/terapia , Padres/psicología , Ensayos Clínicos Controlados Aleatorios como Asunto , Exotropía/cirugía , Humanos , Entrevistas como Asunto , Selección de Paciente , Autonomía Personal , Investigación Cualitativa , Espera VigilanteRESUMEN
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. 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.
Asunto(s)
Protocolos Clínicos , Exotropía/cirugía , Adolescente , Niño , Preescolar , Humanos , Lactante , Evaluación de Resultado en la Atención de Salud , Proyectos Piloto , Investigación Cualitativa , Tamaño de la MuestraRESUMEN
PURPOSE: To describe surgical outcomes in intermittent exotropia (X(T)), and to relate these to preoperative and surgical characteristics. METHODS: 87 children (aged <11 years) underwent surgery in 18 UK centres; review data (mean 21 months post-surgery) were available for 72. The primary outcome measure was motor/sensory outcome (angle and stereoacuity). The secondary outcome measure was satisfactory control assessed by Newcastle Control Score (NCS). RESULTS: 35% of patients had excellent, 28% had fair and 37% had poor primary outcome. Preoperative and surgical characteristics did not influence primary outcome. Satisfactory control was achieved in 65% of patients, while X(T) remained/recurred in 20%. Persistent over-correction occurred in 15% of children. There was no relationship between over-correction and preoperative characteristics or surgical dose/type. Median angle improved by 12 prism dioptres (PD) at near and 19 PD at distance (p<0.001). Median NCS improved by 5 (p<0.001). 40% of those initially over-corrected remained so by last postoperative assessment; no relationship was found between an initial over-correction and good outcome. CONCLUSIONS: Whilst excellent motor/sensory outcome was achieved in one-third and satisfactory control in two-thirds of patients, the 37% poor outcome and 15% persistent over-correction rate is of concern. Surgical dose was similar in those under- and over-corrected, suggesting that over-corrections cannot be avoided merely by getting the dosage right: a randomised controlled trial (RCT) would shed light on this issue. Initial over-correction did not improve the chance of a good outcome, supporting the growing literature on this topic and further highlighting the need for randomised controlled trials of X(T) surgery.
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Exotropía/cirugía , Procedimientos Quirúrgicos Oftalmológicos/métodos , Cuidados Preoperatorios/métodos , Agudeza Visual , Ambliopía/etiología , Niño , Preescolar , Estudios de Cohortes , Educación Médica Continua , Femenino , Estudios de Seguimiento , Humanos , Lactante , Masculino , Procedimientos Quirúrgicos Oftalmológicos/efectos adversos , Procedimientos Quirúrgicos Oftalmológicos/normas , Complicaciones Posoperatorias/etiología , Cuidados Preoperatorios/normas , Resultado del Tratamiento , Reino UnidoRESUMEN
BACKGROUND: The purpose of this study was to investigate current patterns of management and outcomes of intermittent distance exotropia [X(T)] in the UK. METHODS: This was an observational cohort study which recruited 460 children aged < 12 years with previously untreated X(T). Eligible subjects were enrolled from 26 UK hospital ophthalmology clinics between May 2005 and December 2006. Over a 2-year period of follow-up, clinical data were prospectively recorded at standard intervals from enrolment. Data collected included angle, near stereoacuity, visual acuity, control of X(T) measured with the Newcastle Control Score (NCS), and treatment. The main outcome measures were change in clinical outcomes (angle, stereoacuity, visual acuity and NCS) in treated and untreated X(T), 2 years from enrolment (or, where applicable, 6 months after surgery). Change over time was tested using the chi-square test for categorical, Wilcoxon test for non-parametric and paired-samples t-test for parametric data. RESULTS: At follow-up, data were available for 371 children (81% of the original cohort). Of these: 53% (195) had no treatment; 17% (63) had treatment for reduced visual acuity only (pure refractive error and amblyopia); 13% (50) had non surgical treatment for control (spectacle lenses, occlusion, prisms, exercises) and 17% (63) had surgery. Only 0.5% (2/371) children developed constant exotropia. The surgically treated group was the only group with clinically significant improvements in angle or NCS. However, 8% (5) of those treated surgically required second procedures for overcorrection within 6 months of the initial procedure and at 6-month follow-up 21% (13) were overcorrected. CONCLUSIONS: Many children in the UK with X(T) receive active monitoring only. Deterioration to constant exotropia, with or without treatment, is rare. Surgery appears effective in improving angle of X(T) and NCS, but rates of overcorrection are high.
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Exotropía/terapia , Niño , Preescolar , Estudios de Cohortes , Percepción de Profundidad/fisiología , Exotropía/fisiopatología , Femenino , Estudios de Seguimiento , Humanos , Masculino , Evaluación de Resultado en la Atención de Salud , Reino Unido , Visión Binocular/fisiología , Agudeza Visual/fisiologíaRESUMEN
Occupational hazards have been known for centuries, but the creation of facilities capable of carrying out the testing necessary to assess these risks is a comparatively recent development. The Wisconsin State Laboratory of Hygiene (WSLH) created the Wisconsin Occupational Health Laboratory (WOHL) in 1937 to address this need. Since then, WOHL's range of analytical capacity has grown to include an impressive array of assays, including volatile organic compounds, asbestos, silica, environmental lead, bioaerosols, and elemental carbon. WOHL has been a leader in emerging occupational health threats, and has been the primary testing facility for the United State's Occupational Safety and Health Administration's (OSHA) consultation program since 1977. Through it all, WOHL has remained a fee-for-service branch of the WSLH and has not used Wisconsin taxpayer funds to support its day-to-day operations.