Phase 2a randomised controlled feasibility trial of a new 'balanced binocular viewing' treatment for unilateral amblyopia in children age 3-8 years: trial protocol.

INTRODUCTION: Treatments for amblyopia, the most common vision deficit in children, often have suboptimal results. Occlusion/atropine blurring are fraught with poor adherence, regression and recurrence. These interventions target only the amblyopic eye, failing to address imbalances of cortical input from the two eyes ('suppression'). Dichoptic treatments manipulate binocular visual experience to rebalance input. Poor adherence in early trials of dichoptic therapies inspired our development of balanced binocular viewing (BBV), using movies as child-friendly viewable content. Small observational studies indicate good adherence and efficacy. A feasibility trial is needed to further test safety and gather information to design a full trial. METHODS/ANALYSIS: We will carry out an observer-masked parallel-group phase 2a feasibility randomised controlled trial at two sites, randomising 44 children aged 3-8 years with unilateral amblyopia to either BBV or standard occlusion/atropine blurring, with 1:1 allocation ratio. We will assess visual function at baseline, 8 and 16 weeks. The primary outcome is intervention safety at 16 weeks, measured as change in interocular suppression, considered to precede the onset of potential diplopia. Secondary outcomes include safety at other time points, eligibility, recruitment/retention rates, adherence, clinical outcomes. We will summarise baseline characteristics for each group and assess the treatment effect using analysis of covariance. We will compare continuous clinical secondary endpoints between arms using linear mixed effect models, and report feasibility endpoints using descriptive statistics. ETHICS/DISSEMINATION: This trial has been approved by the London-Brighton & Sussex Research Ethics Committee (18/LO/1204), National Health Service Health Research Authority and Medicines and Healthcare products Regulatory Agency. A lay advisory group will be involved with advising on and disseminating the results to non-professional audiences, including on websites of funder/participating institutions and inputting on healthcare professional audience children would like us to reach. Reporting to clinicians and scientists will be via internal and external meetings/conferences and peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT03754153.

Detecting optic nerve head swelling on ultrasound and optical coherence tomography in children and young people: an observational study.

BACKGROUND: Following high-profile cases, referrals for evaluation of 'suspicious optic discs' to eye clinics in the UK have sharply increased, asking ophthalmologists to reliably distinguish between true and pseudopapilloedema. Optic nerve sheath dilatation (ONSD) on ocular ultrasound (US) is considered a reliable sign of true papilloedema, but this test is not widely available. Recently, anterior bowing of Bruch's membrane (BM) and increased retinal nerve fibre layer thickness on optical coherence tomography (OCT) have emerged as indicators of intracranial hypertension, and OCT is widely available. We aimed to evaluate safety and efficacy of the diagnostic workup in our service, with particular emphasis of diagnostic reliability of US and OCT. METHODS: Retrospective service evaluation/cohort study of children and young people younger than 16 years investigated for 'suspicious discs' over a 7-month period in 2016 at a single eye care provider in London, UK. 61 children and young people underwent clinical assessment, US scan and OCT. RESULTS: Of 61 cases, 3 had intracranial pathology. At presentation, only one had ONSD on US and anterior bowing of BM on OCT. Increased nerve fibre layer thickness in at least one of three relevant sectors was observed in two cases. All three cases of intracranial pathology, however, had significant points in their presenting or medical history. CONCLUSION: Ophthalmologists and optometrists must not rely on funduscopy and ocular imaging when assessing a child for possible intracranial disease; history and basic neurological assessment are critical in the diagnostic workup.

Comparison of handheld rebound tonometry with Goldmann applanation tonometry in children with glaucoma: a cohort study.

OBJECTIVE: To test agreement of two methods to measure intraocular pressure (IOP): rebound tonometry (RBT) and gold standard Goldmann applanation tonometry (GAT) in children with glaucoma. DESIGN: Observational prospective cohort study. SETTING: Tertiary paediatric glaucoma clinic at a single centre. PARTICIPANTS: 102 individuals attending a paediatric glaucoma clinic, mean (SD) age 11.85 (3.17), of whom 53 were male. PRIMARY AND SECONDARY OUTCOME MEASURES: Intraocular pressure, central corneal thickness, child preference for measurement method. RESULTS: Limits of agreement for intraobserver and interobserver were, respectively, (-2.71, 2.98) mm Hg and (-5.75, 5.97) mm Hg. RBT frequently gave higher readings than GAT and the magnitude of disagreement depend on the level of IOP being assessed. Differences of 10 mm Hg were not uncommon. RBT was the preferred method for 70% of children. CONCLUSIONS: There is poor agreement between RBT and GAT in children with glaucoma. RBT frequently and significantly overestimates IOP. However, 'normal' RBT readings are likely to be accurate and may spare children an examination under anaesthesia (EUA). High RBT readings should prompt the practitioner to use another standard method of IOP measurement if possible, or consider the RBT measurement in the context of clinical findings before referring the child to a specialist clinic or considering EUA.