Visual crowding in nystagmus and amblyopia
Research type
Research Study
Full title
Visual crowding in congenital nystagmus: A shared basis with amblyopia and unaffected vision?
IRAS ID
217222
Contact name
John Greenwood
Contact email
Sponsor organisation
University College London
Clinicaltrials.gov Identifier
Z6364106/2017/03/153, UCL Data Protection
Duration of Study in the UK
1 years, 0 months, 1 days
Research summary
People with congenital nystagmus are unable to control their eye movements. The problems experienced by these patients go beyond the standard measures of visual acuity used by clinicians. However, additional measures of crowding are rarely appreciated by clinicians, despite having a significant impact on everyday life. In response to these eye movements, vision can become blurry and on occasions people see the world/image move. Of the areas of vision that can be impaired visual acuity is one, another area that has been documented to be reduced is contrast sensitivity, this is the ability for a person to discriminate between an object and the background that they are viewing.
A further impairment may also arise through ‘crowding’ – objects (like letters) become difficult to see in clutter, despite being clear in isolation. Although we do not know why this crowding occurs, we know that crowding also affects peripheral vision in unaffected adults and the central vision of people with amblyopia (‘lazy eye’).
Our aim is to test whether these three forms of crowding occur for the same reason. Our experiments will measure the properties of nystagmic crowding and compare them with crowding in amblyopia and unaffected vision in order to consider whether they are the same process. The outcome will be a sharper understanding of this severe impediment to vision.
We aim to further understand these crowding deficits, both to improve the screening and treatment of the effects of nystagmus on visual function, and to improve the support provided to people suffering this disorder.
REC name
London - London Bridge Research Ethics Committee
REC reference
17/LO/0784
Date of REC Opinion
8 May 2017
REC opinion
Further Information Favourable Opinion