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Mestre C, Neupane S, Manh V, Tarczy-Hornoch K, Candy TR. Vergence and accommodation responses in the control of intermittent exotropia. Ophthalmic Physiol Opt 2023. [PMID: 36692334 DOI: 10.1111/opo.13093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 01/02/2023] [Accepted: 01/03/2023] [Indexed: 01/25/2023]
Abstract
PURPOSE Individuals with different types of intermittent exotropia (IXT) may use neurally coupled accommodation and vergence responses differently from those without exotropia to achieve eye alignment. This study examined the relationship between simultaneously recorded accommodation and vergence responses in children and young adults with a range of types of IXT while aligned and deviated. METHODS Responses of 29 participants with IXT (4-31 years) and 24 age-matched controls were recorded using simultaneous eye-tracking and eccentric photorefraction while they watched a movie in binocular or monocular viewing at varying viewing distances. Gradient response AC/A ratios and fusional vergence ranges were also assessed. Eight participants had divergence or pseudo-divergence excess type IXT, 5 had convergence insufficiency and 16 had basic IXT. RESULTS Control and IXT participants accommodated similarly both in monocular and binocular-aligned conditions to visual targets at 80 and 33 cm. When deviated in binocular viewing, most participants with IXT exhibited changes in accommodation <0.5D relative to alignment. Gradient response AC/A ratios were similar for control [0.56 MA/D (IQR: 0.51 MA/D)] and IXT participants [0.42 MA/D (0.54 MA/D); p = 0.60]. IXT participants showed larger vergence to accommodation ratios with changes from distance to near fixation [1.19 MA/D (1.45 MA/D)] than control participants [0.78 MA/D (0.60 MA/D); p = 0.02], especially among IXT participants with divergence or pseudo-divergence excess. Participants with IXT exhibited typical fusional divergence ranges beyond their dissociated position [8.86 Δ (7.10 Δ)] and typical fusional convergence ranges from alignment [18 Δ (15.75 Δ)]. CONCLUSIONS This study suggests that control of IXT is typically neither driven by accommodative convergence alone nor associated with over-accommodation secondary to fusional convergence efforts. These simultaneous measurements confirmed that proximal vergence contributed significantly to IXT control, particularly for divergence or pseudo-divergence excess type IXT. For IXT participants in this study, achieving eye alignment did not conflict with having clear vision.
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Affiliation(s)
- Clara Mestre
- School of Optometry, Indiana University, Bloomington, Indiana, USA
| | - Sonisha Neupane
- Department of Psychology, Northeastern University, Boston, Massachusetts, USA
| | - Vivian Manh
- Division of Ophthalmology, Seattle Children's Hospital, Seattle, Washington, USA
| | - Kristina Tarczy-Hornoch
- Division of Ophthalmology, Seattle Children's Hospital, Seattle, Washington, USA.,University of Washington, Seattle, Washington, USA
| | - T Rowan Candy
- School of Optometry, Indiana University, Bloomington, Indiana, USA
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Al Jabri S, Kirkham J, Rowe FJ. Development of a core outcome set for amblyopia, strabismus and ocular motility disorders: a review to identify outcome measures. BMC Ophthalmol 2019; 19:47. [PMID: 30736755 PMCID: PMC6368710 DOI: 10.1186/s12886-019-1055-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2018] [Accepted: 01/29/2019] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Core Outcome Sets (COS) are defined as the minimum sets of outcomes that should be measured and reported in all randomised controlled trials to facilitate combination and comparability of research. The aim of this review is to produce an item bank of previously reported outcome measures from published studies in amblyopia, strabismus and ocular motility disorders to initiate the development of COS. METHODS A review was conducted to identify articles reporting outcome measures for amblyopia, strabismus and ocular motility disorders. Using systematic methods according to the COMET handbook we searched key electronic bibliographic databases from 1st January 2011 to 27th September 2016 using MESH terms and alternatives indicating the different subtypes of amblyopia, strabismus and ocular motility disorders in relation to treatment outcomes and all synonyms. We included Cochrane reviews, other systematic reviews, controlled trials, non-systematic reviews and retrospective studies. Data was extracted to tabulate demographics of included studies, primary and secondary outcomes, methods of measurement and their time points. RESULTS A total of 142 studies were included; 42 in amblyopia, 33 in strabismus, and 68 in ocular motility disorders (one study overlap between amblyopia and strabismus). We identified ten main outcome measure domains for amblyopia, 14 for strabismus, and ten common "visual or motility" outcome measure domains for ocular motility disorders. Within the domains, we found variable nomenclature being used and diversity in methods and timings of measurements. CONCLUSION This review highlights discrepancies in outcome measure reporting within published literature for amblyopia, strabismus and ocular motility and it generated an item bank of the most commonly used and reported outcome measures for each of the three conditions from recent literature to start the process of COS development. Consensus among all stakeholders including patients and professionals is recommended to establish a useful COS.
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Affiliation(s)
- Samia Al Jabri
- Department of Health Services Research, University of Liverpool, Waterhouse Building Block B, 2nd Floor, 1-3 Brownlow Street, L69 3GL Liverpool, UK
| | - Jamie Kirkham
- Department of Biostatistics, University of Liverpool, Liverpool, UK
| | - Fiona J. Rowe
- Department of Health Services Research, University of Liverpool, Waterhouse Building Block B, 2nd Floor, 1-3 Brownlow Street, L69 3GL Liverpool, UK
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Clarke M, Hogan V, Buck D, Shen J, Powell C, Speed C, Tiffin P, Sloper J, Taylor R, Nassar M, Joyce K, Beyer F, Thomson R, Vale L, McColl E, Steen N. An external pilot study to test the feasibility of a randomised controlled trial comparing eye muscle surgery against active monitoring for childhood intermittent exotropia [X(T)]. Health Technol Assess 2016; 19:1-144. [PMID: 26005878 DOI: 10.3310/hta19390] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
INTRODUCTION The evidence base for the treatment of strabismus (squint) is poor. Our main aim is to improve this evidence base for the treatment of a common type of childhood squint {intermittent exotropia, [X(T)]}. We conducted an external pilot study in order to inform the design and conduct of a future full randomised controlled trial (RCT). METHODS Children of between 6 months and 16 years with a recent diagnosis of X(T) were eligible for recruitment. Participants were recruited from secondary care at the ophthalmology departments at four UK NHS foundation trusts. Participants were randomised to either active monitoring or surgery. This report describes the findings of the Pilot Rehearsal Trial and Qualitative Study, and assesses the success against the objectives proposed. RECRUITMENT AND RETENTION The experience gained during the Pilot Rehearsal Trial demonstrates the ability to recruit and retain sites that are willing to randomise children to both trial arms, and for parents to agree to randomisation of their children to such a study. One child declined the group allocation. A total of 231 children were screened (expected 240), of whom 138 (60%) were eligible (expected 228: 95%) and 49 (35% of eligible) children were recruited (expected 144: 63% of eligible). Strategies that improved recruitment over the course of the trial are discussed, together with the reasons why fewer children were eligible for recruitment than initially anticipated. Attrition was low. Outcome data were obtained for 47 of 49 randomised children. TRIAL PROCESSES AND DATA COLLECTION The Trial Management processes proved effective. There were high levels of completion on all of the data collection forms. However, the feedback from the treatment orthoptists revealed that some modifications should be made to the length and frequency of the health service assessment and travel assessment questionnaires, thus reducing the burden on participants in the main trial. Modifications to the wording of the questions also need to be made. MONITORING OF BIAS Children who recruited to the trial were older and had more severe strabismus than those children eligible but declining participation. Strategies to account for this in a full trial are proposed. REASONS FOR PARTICIPATION OR DECLINING STUDY These were identified using qualitative interviews. The principal reasons for declining entry into the study were strong preferences for and against surgical treatment. HARMS There were no serious unexpected adverse events. Two children had overcorrection of their X(T) with reduction in binocular vision following surgery, which is in line with previous studies. No children in the active monitoring arm developed a constant strabismus although two showed some reduction in control. CONCLUSIONS The SamExo study has demonstrated that it is possible to recruit and retain participants to a randomised trial of surgery compared with active monitoring for X(T). For longer-term full RCTs, in order to maximise the generalisability of future studies, consideration needs to be given to planning more time and clinic appointments to assess eligibility and to allow consideration of participation; the greater use of research nurses for recruitment; and accommodating the strong preferences of some parents both for and against surgical intervention. TRIAL REGISTRATION Current Controlled Trials ISRCTN44114892. FUNDING This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 19, No. 39. See the NIHR Journals Library website for further project information.
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Affiliation(s)
- Michael Clarke
- Department of Ophthalmology, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle, UK
| | - Vanessa Hogan
- Newcastle Clinical Trials Unit, Institute of Health and Society, Newcastle University, Newcastle, UK
| | - Deborah Buck
- Institute of Neuroscience, Newcastle University, Newcastle, UK
| | - Jing Shen
- Institute of Health and Society, Newcastle University, Newcastle, UK
| | - Christine Powell
- Department of Ophthalmology, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle, UK
| | - Chris Speed
- Newcastle Clinical Trials Unit, Institute of Health and Society, Newcastle University, Newcastle, UK
| | - Peter Tiffin
- Sunderland Eye Infirmary, City Hospitals Sunderland NHS Foundation Trust, Sunderland, UK
| | - John Sloper
- Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Robert Taylor
- Department of Ophthalmology, York Hospitals NHS Foundation Trust, York, UK
| | - Mahmoud Nassar
- Ophthalmology Department, Faculty of Medicine, Minia University, Al-Mini, Egypt
| | - Kerry Joyce
- Institute of Health and Society, Newcastle University, Newcastle, UK
| | - Fiona Beyer
- Institute of Health and Society, Newcastle University, Newcastle, UK
| | - Richard Thomson
- Institute of Health and Society, Newcastle University, Newcastle, UK
| | - Luke Vale
- Institute of Health and Society, Newcastle University, Newcastle, UK
| | - Elaine McColl
- Newcastle Clinical Trials Unit, Institute of Health and Society, Newcastle University, Newcastle, UK
| | - Nick Steen
- Institute of Health and Society, Newcastle University, Newcastle, UK
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Brodsky MC, Horwood AM, Riddell PM. Intermittent exotropia: Are we underminusing by not overminusing? J AAPOS 2015; 19:397-8. [PMID: 26486017 DOI: 10.1016/j.jaapos.2015.05.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Accepted: 05/27/2015] [Indexed: 11/15/2022]
Affiliation(s)
- Michael C Brodsky
- Department of Ophthalmology and Neurology, Mayo Clinic, Rochester, Minnesota.
| | - Anna M Horwood
- Infant Vision Laboratory, School of Psychology and Clinical Language Sciences, University of Reading, United Kingdom
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Lecouturier J, Clarke MP, Errington G, Hallowell N, Murtagh MJ, Thomson R. Treating childhood intermittent distance exotropia: a qualitative study of decision making. BMC Ophthalmol 2015. [PMID: 26296859 DOI: 10.1186/s12886-015-0087-y.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Engaging patients (parents/families) in treatment decisions is increasingly recognised as important and beneficial. Yet where the evidence base for treatment options is limited, as with intermittent distance exotropia (X(T)), this presents a challenge for families and clinicians. The purpose of this study was to explore how decisions are made in the management and treatment of X(T) and what can be done to support decision-making for clinicians, parents and children. METHODS This was a qualitative study using face to face interviews with consultant ophthalmologists and orthoptists, and parents of children with X(T). Interview data were analysed using the constant comparative method. RESULTS The drivers for clinicians in treatment decision-making for X(T) were the proportion of time the strabismus is manifest and parents' views. For parents, decisions were influenced by: fear of bullying and, to a lesser degree, concerns around the impact of the strabismus on their child's vision. Uncertainty around the effectiveness of treatment options caused difficulties for some clinicians when communicating with parents. Parental understanding of the nature of X(T) and rationale for treatment often differed from that of the clinicians, and this affected their involvement in decision-making. Though there were good examples of shared decision-making and parent and child engagement some parents said the process felt rushed and they felt excluded. Parents reported that clinicians provided sufficient information in consultations but they had difficulties in retaining verbal information to convey to other family members. CONCLUSIONS Overall parents were happy with the care their child received but there is scope for better parent and (where appropriate) child engagement in decision-making. There was an expressed need for written information about X(T) to reinforce what was given verbally in consultations and to share with other family members. Access could be via the hospital website, along with videos or blogs from parents and children who have undergone the various management options. A method of assisting clinicians to explain the treatment options, together with the uncertainties, in a clear and concise way could be of particular benefit to orthoptists who have the most regular contact with parents and children, and are more likely to suggest conservative treatments such as occlusion and minus lenses.
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Affiliation(s)
- Jan Lecouturier
- Institute of Health and Society, Newcastle University, Baddiley-Clark Building, Richardson Road, Newcastle upon Tyne, NE2 4AX, UK.
| | - Michael P Clarke
- Newcastle Eye Centre, Royal Victoria Infirmary, Newcastle upon Tyne, NE1 4LP, UK.
| | - Gail Errington
- Faculty of Medicine & Health Sciences, University of Nottingham, Queen's Medical Centre, Nottingham, NG7 2UH, UK.
| | - Nina Hallowell
- Centre for Population Health Sciences, Medical School, The University of Edinburgh, Teviot Place, Edinburgh, EH8 9AG, UK.
| | - Madeleine J Murtagh
- School of Social and Community Medicine, University of Bristol, Oakfield House, Oakfield Grove, Clifton, Bristol, BS8 2BN, UK.
| | - Richard Thomson
- Institute of Health and Society, Newcastle University, Baddiley-Clark Building, Richardson Road, Newcastle upon Tyne, NE2 4AX, UK.
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Lecouturier J, Clarke MP, Errington G, Hallowell N, Murtagh MJ, Thomson R. Treating childhood intermittent distance exotropia: a qualitative study of decision making. BMC Ophthalmol 2015; 15:112. [PMID: 26296859 PMCID: PMC4546303 DOI: 10.1186/s12886-015-0087-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Accepted: 07/22/2015] [Indexed: 11/25/2022] Open
Abstract
Background Engaging patients (parents/families) in treatment decisions is increasingly recognised as important and beneficial. Yet where the evidence base for treatment options is limited, as with intermittent distance exotropia (X(T)), this presents a challenge for families and clinicians. The purpose of this study was to explore how decisions are made in the management and treatment of X(T) and what can be done to support decision-making for clinicians, parents and children. Methods This was a qualitative study using face to face interviews with consultant ophthalmologists and orthoptists, and parents of children with X(T). Interview data were analysed using the constant comparative method. Results The drivers for clinicians in treatment decision-making for X(T) were the proportion of time the strabismus is manifest and parents’ views. For parents, decisions were influenced by: fear of bullying and, to a lesser degree, concerns around the impact of the strabismus on their child’s vision. Uncertainty around the effectiveness of treatment options caused difficulties for some clinicians when communicating with parents. Parental understanding of the nature of X(T) and rationale for treatment often differed from that of the clinicians, and this affected their involvement in decision-making. Though there were good examples of shared decision-making and parent and child engagement some parents said the process felt rushed and they felt excluded. Parents reported that clinicians provided sufficient information in consultations but they had difficulties in retaining verbal information to convey to other family members. Conclusions Overall parents were happy with the care their child received but there is scope for better parent and (where appropriate) child engagement in decision-making. There was an expressed need for written information about X(T) to reinforce what was given verbally in consultations and to share with other family members. Access could be via the hospital website, along with videos or blogs from parents and children who have undergone the various management options. A method of assisting clinicians to explain the treatment options, together with the uncertainties, in a clear and concise way could be of particular benefit to orthoptists who have the most regular contact with parents and children, and are more likely to suggest conservative treatments such as occlusion and minus lenses. Electronic supplementary material The online version of this article (doi:10.1186/s12886-015-0087-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jan Lecouturier
- Institute of Health and Society, Newcastle University, Baddiley-Clark Building, Richardson Road, Newcastle upon Tyne, NE2 4AX, UK.
| | - Michael P Clarke
- Newcastle Eye Centre, Royal Victoria Infirmary, Newcastle upon Tyne, NE1 4LP, UK.
| | - Gail Errington
- Faculty of Medicine & Health Sciences, University of Nottingham, Queen's Medical Centre, Nottingham, NG7 2UH, UK.
| | - Nina Hallowell
- Centre for Population Health Sciences, Medical School, The University of Edinburgh, Teviot Place, Edinburgh, EH8 9AG, UK.
| | - Madeleine J Murtagh
- School of Social and Community Medicine, University of Bristol, Oakfield House, Oakfield Grove, Clifton, Bristol, BS8 2BN, UK.
| | - Richard Thomson
- Institute of Health and Society, Newcastle University, Baddiley-Clark Building, Richardson Road, Newcastle upon Tyne, NE2 4AX, UK.
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Joyce KE, Beyer F, Thomson RG, Clarke MP. A systematic review of the effectiveness of treatments in altering the natural history of intermittent exotropia. Br J Ophthalmol 2014; 99:440-50. [DOI: 10.1136/bjophthalmol-2013-304627] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Buck D, McColl E, Powell CJ, Shen J, Sloper J, Steen N, Taylor R, Tiffin P, Vale L, Clarke MP. Surgery versus Active Monitoring in Intermittent Exotropia (SamExo): study protocol for a pilot randomised controlled trial. Trials 2012; 13:192. [PMID: 23072556 PMCID: PMC3521171 DOI: 10.1186/1745-6215-13-192] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2012] [Accepted: 09/26/2012] [Indexed: 11/10/2022] Open
Abstract
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.
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Affiliation(s)
- Deborah Buck
- Institute of Neuroscience, c/o Clinical Trials Unit, Medical School, Newcastle University, Newcastle upon Tyne, UK
| | - Elaine McColl
- Institute of Health & Society, Baddiley-Clark Building, Newcastle University, Newcastle upon Tyne, UK
| | - Christine J Powell
- Royal Victoria Infirmary Eye Department, Newcastle upon Tyne Hospitals NHS Trust, Newcastle upon Tyne, UK
| | - Jing Shen
- Institute of Health & Society, Baddiley-Clark Building, Newcastle University, Newcastle upon Tyne, UK
| | | | - Nick Steen
- Institute of Health & Society, Baddiley-Clark Building, Newcastle University, Newcastle upon Tyne, UK
| | | | | | - Luke Vale
- Institute of Health & Society, Baddiley-Clark Building, Newcastle University, Newcastle upon Tyne, UK
| | - Michael P Clarke
- Royal Victoria Infirmary Eye Department, Newcastle upon Tyne Hospitals NHS Trust, Newcastle upon Tyne, UK
- Institute of Neuroscience, Medical School, Newcastle University, Newcastle upon Tyne, UK
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