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BMJ Clinical Evidence Jun 2011Amblyopia is commonly associated with squint (strabismus) or refractive errors resulting in different visual inputs to each eye during the sensitive period of visual... (Review)
Review
INTRODUCTION
Amblyopia is commonly associated with squint (strabismus) or refractive errors resulting in different visual inputs to each eye during the sensitive period of visual development (<7-8 years of age). The cumulative incidence is estimated at 2% to 4% in children aged up to 15 years.
METHODS AND OUTCOMES
We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of interventions to detect amblyopia early? What are the effects of medical treatments for amblyopia? We searched: Medline, Embase, The Cochrane Library, and other important databases up to May 2010 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations, such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).
RESULTS
We found 33 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.
CONCLUSIONS
In this systematic review, we present information relating to the effectiveness and safety of the following interventions: active vision therapy; glasses alone or with occlusion; or penalisation to treat amblyopia; and screening to detect amblyopia early.
Topics: Amblyopia; Eyeglasses; Humans; Refractive Errors; Sensory Deprivation; Strabismus; Visual Acuity
PubMed: 21714945
DOI: No ID Found -
Epilepsia Apr 2011Despite the widespread use of antiepileptic drugs (AEDs) across different neurologic and psychiatric disorders, no study has systematically reviewed all available... (Meta-Analysis)
Meta-Analysis Review
PURPOSE
Despite the widespread use of antiepileptic drugs (AEDs) across different neurologic and psychiatric disorders, no study has systematically reviewed all available randomized controlled trials (RCTs) of a given AED to fully uncover its tolerability profile. We aimed at identifying treatment emergent adverse events (AEs) associated with pregabalin through a systematic review and meta-analysis of all available RCTs. We also assessed the association between serious AEs and pregabalin, and investigated whether pregabalin AEs display a dose-response relationship.
METHODS
We searched MEDLINE, EMBASE, and Cochrane CENTRAL to February 2010 for RCTs. Additional studies were identified from reference lists of retrieved papers and from online clinical databases. We selected placebo-controlled, double-blind RCTs investigating the therapeutic effects of pregabalin in adults with any condition. Studies had to include at least 20 subjects per arm and have a duration of at least 4 weeks. AEs were assessed for their association with pregabalin after identification/exclusion of synonyms, rare AEs, and nonassessable AEs due to methodologic limitations. We used relative risks (RRs) to assess the association of any [99% confidence intervals (CIs)] or serious AEs (95% CIs) with pregabalin, and risk differences (RDs, 95% CIs) to investigate dose-response relationships of pregabalin AEs.
KEY FINDINGS
Thirty-eight RCTs were included in our study. Of 39 AEs, 20 (51%) were significantly associated with pregabalin (dizziness, vertigo, incoordination, balance disorder, ataxia, diplopia, blurred vision, amblyopia, tremor, somnolence, confusional state, disturbance in attention, thinking abnormal, euphoria, asthenia, fatigue, edema, peripheral edema, dry mouth, constipation). The highest RRs were found for cognition/coordination AEs. There was no significant association between serious AEs and pregabalin. There was a selective dose-response pattern in the onset of pregabalin AEs, with certain AEs appearing at lower doses than others.
SIGNIFICANCE
Individuals starting treatment with pregabalin are at increased risk for several AEs, particularly those affecting cognition/coordination. Pregabalin AEs appear according to a selective dose-response pattern, possibly reflecting the severity of dysfunction of distinct anatomic structures. These findings may aid clinicians in providing better patient management, and support the value of including in meta-analyses of AED tolerability profiles RCTs performed in different conditions.
Topics: Analgesics; Anticonvulsants; Epilepsy; Humans; Neuralgia; Outcome Assessment, Health Care; Pregabalin; Randomized Controlled Trials as Topic; gamma-Aminobutyric Acid
PubMed: 21320112
DOI: 10.1111/j.1528-1167.2010.02966.x -
Eye (London, England) Apr 2011Amblyopia is a common condition, which can affect up to 5% of the general population. Health-related quality-of-life (HRQoL) implications of amblyopia and/or its... (Review)
Review
Amblyopia is a common condition, which can affect up to 5% of the general population. Health-related quality-of-life (HRQoL) implications of amblyopia and/or its treatment have been explored in the literature. A systematic literature search was undertaken during the period of 7-14 May 2010 to identify the HRQoL implications of amblyopia and/or its treatment. A total of 35 papers were included in the literature review. The HRQoL implications of amblyopia related specifically to amblyopia treatment, rather than to the condition itself. These included impact on family life, social interactions, difficulties in undertaking daily activities, as well as feelings and behaviour. The identified studies adopted a number of methodologies. The study populations included children with the condition, parents of children with amblyopia, and adults who had undertaken amblyopia treatment as a child. Some studies developed their own measures of HRQoL, and others determined HRQoL through proxy measures. The reported findings of the HRQoL implications are of importance when considering the management of cases of amblyopia. The issues identified in the literature review are discussed with respect to how HRQoL is measured (treatment compliance vs proxy measures), and whether HRQoL is taken from a child's or a parent's perspective. Changing societal views over glasses and occlusion therapy are also discussed. Further research is required to assess the immediate and long-term effects of amblyopia and/or its treatment on HRQoL using a more standardised approach.
Topics: Activities of Daily Living; Adult; Amblyopia; Child; Child, Preschool; Family; Health Status; Humans; Interpersonal Relations; Parents; Quality of Life; Severity of Illness Index
PubMed: 21274010
DOI: 10.1038/eye.2011.4 -
The British Journal of Ophthalmology Mar 2011Health-related quality of life (HRQoL) measures are used in healthcare to help inform clinical decision-making and policy-making decisions. A number of disease-specific... (Review)
Review
BACKGROUND/AIMS
Health-related quality of life (HRQoL) measures are used in healthcare to help inform clinical decision-making and policy-making decisions. A number of disease-specific or condition-specific measures have been developed and applied in ophthalmology; however, their use in the specific fields of amblyopia and strabismus are not as established. The purpose of this study is to identify and discuss specific HRQoL instruments that may be used in the investigation and management of patients with amblyopia and/or strabismus.
METHODS
A systematic literature review was undertaken in November 2009. The electronic databases of AMED (Allied and Complementary Medicine: 1985 to November 2009), the British Nursing Index and Archive (1985 to October 2009), Ovid Medline In-Process and Other Non-Indexed Citations and Ovid Medline (1950 to present) and PsycINFO (1806 to November Week 1 2009) were searched. No language restrictions were applied to the search.
RESULTS
Four instruments were identified: the Amblyopia and Strabismus Questionnaire (A&SQ), the Amblyopia Treatment Index (ATI), the Adult Strabismus Questionnaire (AS-20) and the Intermittent Exotropia Questionnaire (IXTQ).
CONCLUSION
The use of HRQoL measures in patients with amblyopia and/or strabismus is a developing area. Further research is necessary to determine the impact of issues such as diplopia and poor cosmesis upon patient groups, and to determine the influence of ethnicity and parental reporting in these patients.
Topics: Amblyopia; Decision Making; Evidence-Based Practice; Female; Health Status; Humans; Male; Quality of Life; Strabismus; Surveys and Questionnaires
PubMed: 20693563
DOI: 10.1136/bjo.2009.178889 -
The Cochrane Database of Systematic... Oct 2009Amblyopia is defined as defective visual acuity in one or both eyes without demonstrable abnormality of the visual pathway, and is not immediately resolved by wearing... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Amblyopia is defined as defective visual acuity in one or both eyes without demonstrable abnormality of the visual pathway, and is not immediately resolved by wearing glasses.
OBJECTIVES
To assess the effectiveness and safety of conventional occlusion versus atropine penalization for amblyopia.
SEARCH STRATEGY
We searched CENTRAL, MEDLINE, EMBASE, LILACS, the WHO International Clinical Trials Registry Platform, preference lists, science citation index and ongoing trials up to June 2009.
SELECTION CRITERIA
We included randomized/quasi-randomized controlled trials comparing conventional occlusion to atropine penalization for amblyopia.
DATA COLLECTION AND ANALYSIS
Two authors independently screened abstracts and full text articles, abstracted data, and assessed the risk of bias.
MAIN RESULTS
Three trials with a total of 525 amblyopic eyes were included. One trial was assessed as having a low risk of bias among these three trials, and one was assessed as having a high risk of bias.Evidence from three trials suggests atropine penalization is as effective as conventional occlusion. One trial found similar improvement in vision at six and 24 months. At six months, visual acuity in the amblyopic eye improved from baseline 3.16 lines in the occlusion and 2.84 lines in the atropine group (mean difference 0.034 logMAR; 95% confidence interval (CI) 0.005 to 0.064 logMAR). At 24 months, additional improvement was seen in both groups; but there continued to be no meaningful difference (mean difference 0.01 logMAR; 95% CI -0.02 to 0.04 logMAR). The second trial reported atropine to be more effective than occlusion. At six months, visual acuity improved 1.8 lines in the patching group and 3.4 lines in the atropine penalization group, and was in favor of atropine (mean difference -0.16 logMAR; 95% CI -0.23 to -0.09 logMAR). Different occlusion modalities were used in these two trials. The third trial had inherent methodological flaws and limited inference could be drawn.No difference in ocular alignment, stereo acuity and sound eye visual acuity between occlusion and atropine penalization was found. Although both treatments were well tolerated, compliance was better in atropine. Atropine penalization costs less than conventional occlusion. The results indicate that atropine penalization is as effective as conventional occlusion.
AUTHORS' CONCLUSIONS
Both conventional occlusion and atropine penalization produce visual acuity improvement in the amblyopic eye. Atropine penalization appears to be as effective as conventional occlusion, although the magnitude of improvement differed among the three trials. Atropine penalization can be used as first line treatment for amblyopia.
Topics: Amblyopia; Atropine; Child; Child, Preschool; Humans; Occlusive Dressings; Ophthalmic Solutions; Randomized Controlled Trials as Topic; Visual Acuity
PubMed: 19821369
DOI: 10.1002/14651858.CD006460.pub2 -
BMC Ophthalmology Jul 2009Amblyopia and amblyogenic factors like strabismus and refractive errors are the most common vision disorders in children. Although different studies suggest that... (Review)
Review
BACKGROUND
Amblyopia and amblyogenic factors like strabismus and refractive errors are the most common vision disorders in children. Although different studies suggest that preschool vision screening is associated with a reduced prevalence rate of amblyopia, the value of these programmes is the subject of a continuing scientific and health policy discussion. Therefore, this systematic review focuses on the question of whether screening for amblyopia in children up to the age of six years leads to better vision outcomes.
METHODS
Ten bibliographic databases were searched for randomised controlled trials, non-randomised controlled trials and cohort studies with no limitations to a specific year of publication and language. The searches were supplemented by handsearching the bibliographies of included studies and reviews to identify articles not captured through our main search strategy.
RESULTS
Five studies met the inclusion criteria. Of these, three studies suggested that screening is associated with an absolute reduction in the prevalence of amblyopia between 0.9% and 1.6% (relative reduction: between 45% and 62%). However, the studies showed weaknesses, limiting the validity and reliability of their findings. The main limitation was that studies with significant results considered only a proportion of the originally recruited children in their analysis. On the other hand, retrospective sample size calculation indicated that the power based on the cohort size was not sufficient to detect small changes between the groups. Outcome parameters such as quality of life or adverse effects of screening have not been adequately investigated in the literature currently available.
CONCLUSION
Population based preschool vision screening programmes cannot be sufficiently assessed by the literature currently available. However, it is most likely that the present systematic review contains the most detailed description of the main limitations in current available literature evaluating these programmes. Therefore, future research work should be guided by the findings of this publication.
Topics: Amblyopia; Child, Preschool; Epidemiologic Studies; Humans; Outcome Assessment, Health Care; Program Evaluation; Vision Screening
PubMed: 19607693
DOI: 10.1186/1471-2415-9-3 -
BMJ Clinical Evidence Sep 2009Amblyopia is commonly associated with squint (strabismus) or refractive errors resulting in different visual inputs to each eye during the sensitive period of visual... (Review)
Review
INTRODUCTION
Amblyopia is commonly associated with squint (strabismus) or refractive errors resulting in different visual inputs to each eye during the sensitive period of visual development (<7-8 years of age). The cumulative incidence is estimated at 2% to 4% in children aged up to 15 years.
METHODS AND OUTCOMES
We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of interventions to detect amblyopia early? What are the effects of medical treatments for amblyopia? We searched: Medline, Embase, The Cochrane Library, and other important databases up to May 2008 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations, such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).
RESULTS
We found 16 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.
CONCLUSIONS
In this systematic review, we present information relating to the effectiveness and safety of the following interventions: active vision therapy; glasses alone or with occlusion; or penalisation to treat amblyopia; and screening to detect amblyopia early.
Topics: Amblyopia; Eyeglasses; Humans; Mydriatics; Sensory Deprivation; Strabismus; Visual Acuity
PubMed: 21726480
DOI: No ID Found -
Health Technology Assessment... Jun 2008To estimate the cost-effectiveness of screening for amblyopia and strabismus in children aged up to 4-5 years, also identifying the major areas of uncertainty and so... (Review)
Review
The clinical effectiveness and cost-effectiveness of screening programmes for amblyopia and strabismus in children up to the age of 4-5 years: a systematic review and economic evaluation.
OBJECTIVES
To estimate the cost-effectiveness of screening for amblyopia and strabismus in children aged up to 4-5 years, also identifying the major areas of uncertainty and so inform future research priorities in this disease area.
DATA SOURCES
Major electronic databases were searched in January 2006.
REVIEW METHODS
Systematic literature reviews were undertaken to determine the prevalence and natural history, the screening methods, the effectiveness of treatment options and health-related quality of life issues relating to amblyopia and strabismus. The review of treatment interventions was restricted to high-quality reviews, meta-analyses and guidelines. The data derived from the review informed the structure and implementation of the decision-analytic model.
RESULTS
The amblyopia screening model was analysed in detail to estimate the cost and effects of six alternative screening options comprising screening at different ages (3, 4 and 5 years) and using alternative sets of tests (visual acuity testing and the cover tests, with and without autorefraction). The reference case results showed that screening programmes that included autorefraction dominated screening programmes without autorefraction. Analyses based on the cost per case of amblyopia prevented showed screening at either 3 or 4 years prevented additional cases at a low absolute cost (3000-6000 pounds sterling). However, when these results were extrapolated to estimate the cost per quality-adjusted life-year (QALY) gained, the reference case analysis found that no form of screening is likely to be cost-effective at currently accepted values of a QALY. The wide-ranging sensitivity analyses found that the results were robust to most parameter changes. The only parameter that radically affected the results was the utility effect of loss of vision in one eye. No direct evidence of a utility effect was identified and the reference case assumed no effect. When a small effect is assumed (a reduction in utility of 2%), the incremental cost per QALY gained becomes extremely attractive for screening at both 3 and at 4 years. The expected value of perfect information was shown to be large when the unilateral vision loss utility parameter was allowed to vary, but not when it was kept constant at zero.
CONCLUSIONS
The results show that the cost-effectiveness of screening for amblyopia is dependent on the long-term utility effects of unilateral vision loss. There is limited evidence on any such effect, although our subjective interpretation of the available literature is that the utility effects are likely to be minimal. Any utility study investigating such effects would need to be careful to avoid introducing bias. The reference case model did not represent potential treatment-related utility effects, primarily due to an increased probability of treated children being bullied at school. The evidence indicates that this may be a problem, and additional sensitivity analyses show that small utility decrements from bullying would improve the cost-effectiveness of early screening significantly. A prospective study of the utility effects of bullying would usefully inform the analysis, although such a study would need to be carefully planned in order to distinguish whether the overall incidence of bullying decreases with reduced school-age treatment, or whether it is displaced to other children.
Topics: Amblyopia; Child, Preschool; Cost-Benefit Analysis; Humans; Prevalence; Quality-Adjusted Life Years; Randomized Controlled Trials as Topic; Strabismus; Vision Screening
PubMed: 18513466
DOI: 10.3310/hta12250 -
The Cochrane Database of Systematic... Jul 2006Stimulus deprivation amblyopia (SDA) develops due to an obstruction to the clear passage of light, preventing clear formation of an image on the retina for example,... (Review)
Review
BACKGROUND
Stimulus deprivation amblyopia (SDA) develops due to an obstruction to the clear passage of light, preventing clear formation of an image on the retina for example, cataract, ptosis (droopy eyelid). It is particularly severe and can be resistant to treatment and the visual prognosis is often poor. Stimulus deprivation amblyopia is rare and precise estimates of prevalence difficult to come by; it probably constitutes less than 3% of all cases of amblyopia. In developed countries most patients present under the age of one; in less developed parts of the world presentation is likely to be significantly later than this.The mainstay of treatment is patching of the better-seeing eye but regimes vary, treatment is difficult to execute and results are often disappointing.
OBJECTIVES
The objectives of this review were to evaluate the effectiveness of occlusion treatment for SDA, determine the optimum treatment regime and factors that may affect outcome.
SEARCH STRATEGY
We searched the Cochrane Central Register of Controlled Trials - CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) on The Cochrane Library (2006, Issue 1), MEDLINE (1996 to April 2006), EMBASE (1980 to April 2006) and LILACS (Latin American and Caribbean Literature on Health Sciences) (to November 2004). There were no date or language restrictions.
SELECTION CRITERIA
We aimed to include randomised and quasi-randomised controlled trials of subjects with unilateral SDA defined as worse than 0.2 LogMAR or equivalent. There were no restrictions with respect to age, gender, ethnicity, co-morbidities, medication use, and the number of participants.
DATA COLLECTION AND ANALYSIS
Two authors independently assessed study abstracts identified by the electronic searches.
MAIN RESULTS
No trials were identified that met the inclusion criteria.
AUTHORS' CONCLUSIONS
It is not possible to conclude how effective treatment for SDA is or which treatment regime produces the best results. There is a need for further study in this area.
Topics: Amblyopia; Blepharoptosis; Cataract; Child, Preschool; Humans; Infant; Occlusive Dressings; Treatment Outcome
PubMed: 16856079
DOI: 10.1002/14651858.CD005136.pub2