Publications by authors named "Michael P Clarke"

Purpose: To comprehensively assess the Randot Preschool stereo test in young children, including testability, normative values, test/retest reliability and sensitivity and specificity for detecting binocular vision disorders.

Methods: We tested 1005 children aged 2-11 years with the Randot Preschool stereo test, plus a cover/uncover test to detect heterotropia. Monocular visual acuity was assessed in both eyes using Keeler Crowded LogMAR visual acuity test for children aged 4 and over.

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Purpose: To describe a new stereotest in the form of a game on an autostereoscopic tablet computer designed to be suitable for use in the eye clinic and present data on its reliability and the distribution of stereo thresholds in adults.

Methods: Test stimuli were four dynamic random-dot stereograms, one of which contained a disparate target. Feedback was given after each trial presentation.

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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.

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Purpose: To assess the impact of cataract surgery on cognition, mood, and visual hallucinations in a cohort of patients aged 75 years and older.

Setting: Secondary care ophthalmology unit in Northeast England.

Design: Prospective observational cohort study.

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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.

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Background: In light of the growing number of people with dementia and age-related cataract, as well as changing anesthetic practices for cataract surgery, this study aimed to explore the experiences of cataract surgeons in managing patients with dementia and making anesthetic decisions.

Methods: This was a qualitative study using semistructured interviews with senior cataract surgeons from two centers in England. Fourteen surgeons were interviewed, and a thematic approach informed by grounded theory was used for the analysis.

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Background/aims: To assess the impact of impaired cognition on visual outcomes 1 year following cataract surgery in a cohort of older people.

Methods: Participants aged 75 years or more with bilateral cataract and scheduled for cataract surgery were recruited consecutively. Cognition was assessed using the revised Addenbrooke's cognitive examination (ACE-R).

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Evidence of effectiveness of interventions for treatment of childhood intermittent exotropia, X(T), is unclear. We conducted a systematic review to locate, appraise and synthesise evidence of effectiveness, including twelve electronic databases, supplemented with hand searches and expert contact. We included randomised controlled trials, quasi-experimental and cohort studies with a comparison group examining interventions for divergence excess, simulated divergence excess or basic type X(T) in children, up to and including 18 years of age, followed for at least 6 months.

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Objective: After treatment with refractive correction and patching, some patients have residual amblyopia resulting from strabismus or anisometropia. We conducted a clinical trial to evaluate the effectiveness of increasing prescribed daily patching from 2 to 6 hours in children with stable residual amblyopia.

Design: Prospective, randomized, multicenter clinical trial.

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Purpose: Common age-related eye diseases including glaucoma, cataract and age-related macular degeneration (AMD) have been proposed to be associated with dementia. Few studies have examined the relationship between cognition and cataract or glaucoma. We explored the association between cognition and cataract and glaucoma diagnoses in community-dwelling 85-year-olds.

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Parkinson's disease, typically thought of as a movement disorder, is increasingly recognized as causing cognitive impairment and dementia. Eye movement abnormalities are also described, including impairment of rapid eye movements (saccades) and the fixations interspersed between them. Such movements are under the influence of cortical and subcortical networks commonly targeted by the neurodegeneration seen in Parkinson's disease and, as such, may provide a marker for cognitive decline.

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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.

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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).

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Background: cognitive test scores and visual acuity are strongly associated in older people. This may be due to poor vision limiting performance on cognitive tasks specifically requiring vision, or an association between visual and neurodegenerative disorders.

Objective: to explore, using data from the Newcastle 85+ cohort study, the impact of sight impairment (SI) on Mini-Mental State Examination (MMSE) scores and whether reduced scores among SI participants are limited to tasks requiring vision.

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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.

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Purpose: To evaluate the PedsQLs performance in children with intermittent exotropia (X[T]) in terms of feasibility, internal consistency, floor-ceiling effects and levels of parent-child agreement.

Methods: Children with X(T) aged <12 years were recruited from 26 UK Hospital Eye Clinics/Orthoptic Departments. QOL was assessed using child (n = 166) and proxy (n = 392) versions of the PedsQLv4.

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Purpose: To investigate the cortical mechanisms that prevent diplopia in intermittent exotropia (X(T)) during binocular alignment (orthotropia).

Methods: The authors studied 12 X(T) patients aged 5 to 22 years. Seventy-five percent had functional stereo vision with stereoacuity similar to that of 12 age-matched controls (0.

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Intermittent exotropia is a common oculomotor anomaly where one eye intermittently deviates outwards. Patients with this type of strabismus are often not aware of the exodeviation and do not usually experience diplopia. In this review, we discuss what is known about the cortical mechanisms which achieve single vision during exodeviation in this condition, and highlight some outstanding questions.

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Purpose: Autosomal dominant optic atrophy (DOA) is a major cause of visual impairment in young adults that is characterized by selective retinal ganglion cell loss. To define the prevalence and natural history of this optic nerve disorder, we performed a population-based epidemiologic and molecular study of presumed DOA cases in the north of England.

Design: Case series.

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