Babies in Glasses; a Feasibility Study.

Overview

This is a feasibility study to begin investigating the possibility that early use of near vision glasses will improve vision in infants at risk of Cerebral Visual Impairment (CVI), leading to further improvement in other areas of development. This active intervention, starting at either 2 or 4 months of age (depending on randomisation), could be more effective than waiting until a problem is detected before giving glasses. As this is a feasibility study, the investigators are looking at a small sample of babies (n=75) to see whether their parents/carers are willing to take part in a 3-arm study comparing two differently timed interventions to a control group, as well as looking at different aspects of the research plan in preparation for a larger final study.

The aim of this study is to assess the feasibility and the acceptability of randomisation and the intervention, namely near vision glasses, from parents of very young babies at risk of Cerebral Visual Impairment (CVI). All infants are born with an immature visual system, and for vision to develop normally, a clear image needs to transmit to the visual centres of the brain. Good vision plays an important role in facilitating normal development so if CVI goes unnoticed, it can have a damaging effect on the child's early development, and subsequent education and quality of life. Children use their sight to learn to walk, talk, think and communicate. For this reason, early intervention has the potential to have positive effects on children's vision and general development. Previous studies have shown that up to 75% of school age children, who have CVI, have difficulty focussing their eyes on a near target, so near objects, such as their hands and parents' faces, will appear blurry. These studies also showed that wearing glasses for near focus improved vision but has not been assessed in babies. This is a single-centre, parallel group, open-label feasibility trial to assess the feasibility of testing the effect near vision glasses (full cycloplegic refraction plus 3.00D add for near) could have on the visual and developmental outcome in babies at risk of brain injury. Infants at risk of developing CVI include those who have had hypoxic ischaemic encephalopathy (HIE) and those born prematurely before 29 weeks gestation. The paediatric research optometrist will enrol and assess all eligible babies of consenting families; first visit at 8 or 16 weeks corrected gestational age, depending on randomisation. Each infant will be followed up 3 months and 6-months (+/- 3 weeks) after the first visit. There are three main areas of the assessment, which will be leading to potential primary outcome measures: 1. Visual Responses (including visual acuity and refractive status) At each visit, vision will be evaluated using Atkinson's battery for Child Development for Examining Functional Vision (ABCDEFV) according to the child's age and their ability. This comprises age-appropriate core vision tests (such as visual acuity and fixing and following) as well as additional tests that assess visual perception and visuomotor behaviour. If visual acuity cannot be obtained using Keeler acuity cards, as per ABCDEFV, the children will receive a measure using a Near Detection Scale (NDS). 2. General Development and Neurodevelopmental Delay Non-visual developmental assessments will include the Bayley Scales of Infant Development - 3rd edition (BSID-III) assessment as appropriate for age at routine neonatal clinical appointments at 3, 6,12 and 24 months (not the research clinics). A Prechtl video will also be performed at the 3-month appointment to assess the presence of fidgety movements. The presence of these movements at 3 months corrected gestational age has been strongly correlated with normal motor development. 3. Functional broadband near infrared spectroscopy (fBNIRS) i. Identification of changed functional haemodynamic and metabolic response to visual stimulus in infants at risk of visual dysfunction. ii. Assessment of changes in functional response in relation to response to glasses Eligible children with consenting parents will be screened for high refractive error prior to randomisation by the research optometrist to avoid post-randomisation dropouts. Evidence of high refractive error (more than -6.00D spherical equivalent or +8.00D spherical equivalent) will result in a referral to ophthalmology and exclusion from the study due to the possibility of associated ocular pathology with high refractive error. All of the above assessments have been organised at University College London Hospitals (UCLH). If the infant is randomised to get glasses, they will be given a near vision spectacle prescription (full cycloplegic refraction plus 3.00D add for near) to take to Great Ormond Street Hospital Eye Department dispensing optician to get the special glasses ordered. Expert ethical advice has been sought through the NIHR's Research Design Service to check on the dimension of potential harm (with a positive review). Each case will be monitored by the independent data monitoring and ethics committee (IDMEC) using follow up data who will report to the trial steering committee (TSC). The IDMEC, Trial Steering Committee (TSC) and Trial Management Group (TMG) will oversee the conduct of this trial.