Relationship between retinal structure and function in early glaucoma
Research type
Research Study
Full title
The relationship between retinal structure and function in early glaucoma.
IRAS ID
315556
Contact name
Alison Binns
Contact email
Sponsor organisation
City, University of London
Duration of Study in the UK
3 years, 4 months, 1 days
Research summary
Glaucoma is a progressive pathology of optic nerve that can lead to blindness. The precise disease mechanisms are not fully understood, but elevated eye pressure is a risk factor. If glaucoma is detected early, it can be effectively managed using pressure lowering eye drops, or by simple surgical procedures. Therefore, early detection and treatment is crucial to minimize the risk of irreversible visual impairment.
Clinically, the mainstay of visual function assessment in people at risk of glaucoma is the measurement of visual field sensitivity. However, visual field defects only manifest when a significant proportion of retinal ganglion cells have died. For this reason, there is a strong research drive to develop visual function tests which provide a more sensitive method of early glaucoma detection.
Papilledema is caused by pressure on optic nerve head (ONH) that occurs as a result of elevated cerebral spinal fluid (CSF) pressure on the optic nerve sheath. Regardless of the cause of ONH swelling, severe to irreversible visual loss is expected if papilledema is left untreated. Glaucoma and papilledema are two conditions where retinal ganglion cells (RGCs) and hence retina nerve fibre layer (RNFL), are damaged due to the pressure differences across the lamina cribrosa (separating the intraocular and intracranial pressure compartments). In papilledema, the loss of RGCs and subsequent thinning of RNFL can occur more rapidly with correspondingly greater loss of visual function.
Using customised different tests that probe different aspects of function such as contrast, colour and rapid flicker thresholds alongside retinal imaging has potential to improve our understanding of the structure-function relationship in normal ageing and in neurodegenerative pathologies like glaucoma and papilledema. This, in turn, may help to advance the diagnosis and recovery of the conditions.
The overall aim of this project is to assess the ability of contrast, colour, and rapid flicker thresholds to distinguish between people with and without glaucoma and papilledema, and to act as a biomarker for disease severity. An additional aim will be to determine whether adjusting the functional test results for structural changes in the eye increases their sensitivity to disease onset and severity.
People with glaucoma, papilledema and ocular hypertension will be recruited from St Thomas’ Hospital. A brief eye assessment, three computer-based visual function tests and ocular imaging will be performed in a single visit (~2 hours in duration) at City University with regular breaks in between. Data will be compared to results from healthy controls of a similar age.REC name
London - City & East Research Ethics Committee
REC reference
22/LO/0690
Date of REC Opinion
18 Oct 2022
REC opinion
Favourable Opinion