Reticular pseudodrusen and choroidal thickness: Can structural markers be used as a surrogate for patient reported visual function?
1st supervisor: Dr Irene Ctori
2nd supervisors: Dr Alison Binns, Dr Tamsin Callaghan
Reticular pseudodrusen (RPD) have recently been recognised as an additional clinical phenotype of age-related macular degeneration (AMD), with distinct characteristics on multimodal imaging. Grading RPD in patients with early AMD is important as the presence of RPD is linked with a greater risk of progression to advanced forms of the condition. There may also be a reduction in choroidal thickness (CT) and retinal thickness associated with RPD, however it is unclear if this precedes or is as a result of RPD development.
Recent research has indicated that there may be a significant impact on visual function associated with RPD and/or choroidal thinning. These changes include an exaggeration of age related deficits in rod-mediated retinal function, such as prolonged dark adaptation. The impact of RPD on the cone system is less well understood.
Whilst it is valuable to know how the presence of RPD or choroidal thinning impacts on clinical measures of visual function, in terms of primary care clinical decision making and in developing outcome measures for clinical trials it is important to know the implications of these changes on the patient experience.
The overall objective of this PhD is to determine how the presence and extent of RPD and choroidal thinning influence patient reported visual function. The intention will be to work towards defining ‘minimally important differences’ (MIDs) in the structural changes i.e. to characterise how big a change in these parameters is required to impact the patients’ perception of visual function.
The specific aims of this project are to:
- Establish a grading scheme for RPD and CT based on multi-modal imaging including fundus photography, OCT and OCT angiography;
- Use a battery of visual function tests including (but not restricted to) Visual Acuity, microperimetry and dark adaptation, in order to determine the correlation with grade of RPD and/or CT in patients with AMD of different severity;
- Investigate the correlation between the RPD and CT grades and with self-reported measures of visual function. The latter will be assessed using questionnaires such as the low luminance questionnaire (LLQ) and the visual function quality of life questionnaire (VFQ-48);
- Determine the MID for the structural and functional tests;
- Determine what combination of clinical tests (both structural and functional) best predict self-reported visual function.
Recommended Skills / Prior Learning
- Post-graduate experience desirable but not essential.