Prof Rachel North
My research interests include:
- Diabetes & its ocular complications
- Vision & falls in the elderly
- Retinal function in cystic fibrosis
My primary areas of research involve two of the major causes of blindness, diabetes mellitus and glaucoma. The early detection of both conditions is important for their management and improved prognosis, and we have been investigating the structural and functional changes using digital imaging, electrophysiological and psychophysical techniques.
The diabetes studies have been investigating the risk factors for the development of diabetic retinopathy in children and adults with Type 1 and Type 2 diabetes mellitus. We have found that patients with diabetes have functional changes prior to visible diabetic retinopathy and have investigated whether this functional loss detected in the early stages of eye disease is reversible. We found that oxygen inhalation has partially reversed functional loss in patients without diabetic retinopathy and we are currently studying patients with cystic fibrosis with and without diabetes.
The ability to detect structural changes to the retina have been evaluated using digital imaging techniques including scanning laser ophthalmoscopy, retinal thickness analyser, and stereoscopic fundus photography. We have also examined the choroidal structure using the 1050nm optical coherence tomography and found that the choroidal thickness is increased in diabetic patients. We found that the central choroid is thinner in all type 2 diabetic eyes regardless of disease stage, ie with or without clinically significant diabetic macular oedema.
Figure 1: Examples of retinal, choroidal thickness maps and enface tomograms from 4 diabetic (A-D with advancing retinopathy from NDR to CSME) and healthy subjects (E).
(Modified from Esmaeelpour et al, Invest Ophthalmol Vis Sci 2011)
The early detection of glaucoma has been studied by electrophysiological assessment of ganglion cell function, ocular blood flow and digital imaging of the optic nerve head. We have shown that electrophysiological measures are not only depressed prior to visual field loss in patients with glaucoma, but also in patients with ocular hypertension. This indicates that there may be dysfunction despite a normal structural appearance to the optic nerve head.
Methods for improving the clinical detection of glaucomatous optic neuropathy and its progression are being studied by using stereoscopic optic nerve head images.
In addition, we are using 1050nm optical coherence tomography (OCT) to create 3D volumetric datasets of the normal and glaucomatous optic nerve head in vivo in order to characterise optic nerve head parameters that have the potential to stage and/or predict glaucomatous optic neuropathy. In particular we are investigating the lamina cribrosa, in optic nerve heads at risk. We are also examining the relationship between the changes that take place in the optic nerve head comparison to those in the retina and choroid.
A 1050nm image of pores from a healthy subject and
B from a patient with advanced glaucoma.
Funding has been awarded from: British Council for Prevention of Blindness, College of Optometrists, Diabetes UK, Welsh office for Research & Development, NERC, The Wellcome Trust, Raynauds & Scleroderma Association and The BUPA Foundation, Pfizer, Welsh Energy Research, Action Medical Research, Fight For Sight, UK & Eire Glaucoma Society & American Health Assistance Foundation.
RV North, J Kenkre, Alison Cooper, R Van Deursen, Survey of vision screening services provided for stroke patients in Wales, NISCHR/Wales School of Primary Care Research 2012, £8,375
Albon J, North RV, Morgan JE. The use of 1050nm OCT to identify changes of optic nerve head pathophysiology in glaucoma, College of Optometrists, 2011-2014. £52,688,
Albon J, North RV, Morgan JE, Disks at Risk. American Health Assistance Foundation, 2011-13. $100,000
Albon J, North RV, Drexler W, Morgan JE, , Optic nerve head changes in the progression of glaucomatous optic neuropathy using 1m OCT, Hirsch and Fight for Sight Award, 2010-11. £15,000
North RV, Albon J, Drexler W, Three dimensional imaging of the ageing and glaucomatous optic nerve head: risk factors for the development of open-angle glaucoma. UK&Eire Glaucoma Society and International Glaucoma Association, 2008-09. £20,000.
Dr Julie Albon, Cardiff University
Professor James Morgan, Cardiff University
Dr Barbara Ryan, Cardiff University
Professor David Owens, Swansea University,
Prof Joyce Kenkre, Glamorgan University,
Dr Allison Cooper, OPAN, Swansea University,
Thierry Zeyen, Leuven University, Belgium;
Professor Wolfgang Drexler, University of Vienna, Austria
Currently have collaborations with School of Computer Science, School of Medicine, Dept of Primary Care and Public Health, Llandough Hospital, Dept of Physiotherapy, School of Healthcare Studies.