Updated on
What did the project achieve?
Between two and five out of 100 children in the UK have amblyopia – meaning they have better vision in one eye than the other and rely on their good eye to see.1 It is usually treated by wearing glasses for a lengthy amount of time to provide clear images to both eyes before using a patch over the good eye to stimulate the weaker eye. However, there has been a lack of evidence about exactly how long children should wear their glasses and patches to get the best out of treatment.
Dr Frank Proudlock and colleagues at the University of Leicester, Professor Irene Gottlob and Michael Hisaund, co-led the first randomised controlled clinical trial to explore whether an extended period of wearing glasses before patching improves the success rate of amblyopia treatment.
“Our study provides robust evidence for the best approach for treating lazy eye, or amblyopia, which is the most common cause of vision problems in children in the UK,” says Dr Proudlock. “We found that patching sooner without a long period of glasses wearing helps to correct the disorder more effectively in most children, leading to improved vision and treatment satisfaction.”
This was a multicentre collaboration involving 30 hospitals around Europe. The team recruited 334 children, aged between three and eight years old, who required treatment for a lazy eye and were split randomly into two groups. One group wore glasses for an extended period of 18 weeks before patching – while the other group wore glasses for only three weeks before patching.
The results showed that more children were successfully treated for amblyopia in the early patching group (66.7%) compared to the group with the extended period of wearing glasses (53%) – and this was true at 12, 18 and 24 weeks after patching. However, one group of younger children, with less severe amblyopia, did benefit from a lengthier period of wearing glasses before patching as they were most likely to improve during this time.
“We measured the improvement in vision as the main outcome but we also found, using questionnaires, that families preferred to start patching without a period of prolonged glass wear. The number of hours of patching needed was equal in both groups. Since younger children with less severe visual loss responded better to initial treatment with glasses, our study introduced an important advancement in personalised medicine,” says Dr Proudlock.
The team hopes these recommendations will soon get incorporated into clinical guidelines so more children can receive optimised treatment for amblyopia – both in the UK and around the world.
Reference
- Tailor, V. et al. Childhood amblyopia: current management and new trends. British Medical Bulletin 2016; 119(1): 75-86.
This research was completed on
Around two per cent of children have a lazy eye – also known as amblyopia.1,2 Eye patches placed over the ‘good’ eye have been used to treat lazy eye for over 250 years.3 Today, children normally wear glasses to improve focussing before using an eye patch, but controversy remains over the relative benefits of these two approaches. Dr Frank Proudlock, of the University of Leicester, is running a clinical trial to gather hard evidence on what sort of treatment is best.
What is the problem and who does it affect?
“Lazy eye is the most common cause of vision problems in children in the UK,” explains Dr Proudlock.3.4 “Around 90 per cent of work by children’s eye services here is related to these problems.”3
Children with a lazy eye have better vision in one eye than the other and rely on their good eye to see. It’s thought the brain chooses to ignore images from the worse eye, the lazy eye. Triggers for this include things that stop children’s eyes from working together properly, such as a squint and focussing problems – such as being far-sighted – that affect one eye more than the other.
“Children with amblyopia often can’t see properly in three dimensions. They can have difficulties judging distance and with hand-eye coordination, which can leave them accident prone and make things like catching a ball difficult,” explains Dr Proudlock. “Reading can be affected too.”
“Children are usually treated first with glasses to correct focussing problems. Next, they also wear a patch over the good eye, which forces the brain to start using the lazy eye again. However, a lack of hard evidence means many questions remain over just how long children need to wear their glasses and their patch for in order to get the best out of treatment.”
What is the project trying to achieve?
“We aim to provide robust evidence on how quickly children with a lazy eye should begin using an eye patch after they start wearing glasses – whether it’s better to wait three or 18 weeks,” says Dr Proudlock. “It might be that wearing glasses for longer means children don’t have to use an eye patch for so long. If so, this could prove very beneficial as children can find wearing patches distressing, and their use can lead to bullying and low self-esteem.”
Around 350 children aged three to eight years are taking part in what’s called a randomised controlled clinical trial.
“Another important consideration is whether children actually wear their glasses as much as they should,” says Dr Proudlock. “We are investigating whether this influences treatment success by using small electronic monitors fixed onto the children’s glasses. We are also assessing whether the underlying cause of the children’s lazy eye – a squint, short-sightedness and so on - affects what sort of treatment is best.”
What are the researchers’ credentials?
Dr Proudlock is a world expert in researching lazy eye and another condition called nystagmus, where the eyes move to and fro uncontrollably. He is working with a multidisciplinary team of doctors, scientists and orthoptists who have an excellent track record after 12 years of collaborative research. (Orthoptists test for lazy eye and other problems that relate to how the eyes move and work together.)
References
- Powell C, Hatt SR. Vision screening for amblyopia in childhood. Cochrane Database Syst Rev 2009 Jul 8;(3):CD005020. doi: 10.1002/14651858.CD005020.pub3
- NHS Evidence – eyes and vision. Annual evidence update on amblyopia. 27 September 2010. http://www.nelm.nhs.uk/en/NeLM-Area/News/2010---September/27/NHS-Evidenc...
- Stewart CE et al. Treatment dose–response in amblyopia therapy: the Monitored Occlusion Treatment of Amblyopia Study (MOTAS). Invest Ophthalmol Vis Sci 2004 45 (9): 3048-54.
- Medline Plus. Amblyopia. http://www.nlm.nih.gov/medlineplus/ency/article/001014.htm Website accessed 19 February 2013.
| Project Leader | Dr Frank A Proudlock PhD, MSc, BSc |
| Project Team | Professor Irene Gottlob MD Univ Doz FRCOphthDr Annegret Dahlmann-Noor Dr med PhD FRCOphth FRCS(Ed) DipMedEd |
| Project Location | Ophthalmology Group, University of Leicester |
| Project Location Other | Paediatric Ophthalmology and Strabismus, NIHR BRC Moorfields Eye HospitalUniversity College London Institute of Ophthalmology |
| Project duration | 3 years |
| Date awarded | 15 November 2012 |
| Project start date | 15 August 2013 |
| Project end date | 14 August 2022 |
| Grant amount | £199,207 |
| Grant code | GN2099 |
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