Dr Allannah Gaffney
Age-related macular degeneration (AMD) is the primary cause of irreversible vision loss in the UK and the developed world. In recent years, effective treatment strategies have evolved for this disease and in order to monitor the outcomes of treatment, as well as to expedite the development of new interventions, it is important to develop tools that are capable of monitoring the very earliest changes in visual function. I am particularly interested in refining functional markers that can be used to diagnose and monitor AMD in this way. In addition, I am also interested in the development and validation of high quality rehabilitation services for individuals with visual impairment.
2012: PhD (Optometry and Vision Sciences), "Characterising adaptational dysfunction in age-related macular degeneration", Cardiff University
2008: MCOptom, College of Optometrists
2007: BSc (Hons) (First class honours in Optometry and Vision Sciences), Cardiff University
My current teaching responsibilities include:
- OP3104 – Abnormal Ocular Conditions, 'Grand Rounds': I am responsible for the Clinical Decision Making component of Grand Rounds, during which I lead small groups discussions of clinical case scenarios in order to encourage our third year students to start 'thinking like Optometrists'
- OP3205 – Occupational Optometry, Law and Business: I deliver a series of Occupational Optometry lecture to 3rd year students.
- OP3101 – Clinical Studies and dispensing: I have been involved in supervision of undergraduate optometry student in a range of clinical settings during my time at Cardiff. Currently, I support third year students while they provide eye examinations to members of the public in the Primary Eye Care Clinic.
My primary research interests include the refinement of functional markers that can be used to diagnose and monitor Age-related Macular Degeneration (AMD), as well as the development and validation of high quality rehabilitation services for individuals with visual impairment.
Early detection of Age-related Macular Degeneration
Age-related macular degeneration is the primary cause of irreversible vision loss in the UK and the developed world. The prevalence of this disease will continue to increase over the coming decades as the average age of the global population rises, so it is important to develop tests that are sensitive to early changes in vision in order to identify individuals that have a high risk of developing AMD, to identify patients that would benefit from treatment, to assess the outcomes of that treatment and to evaluate emerging treatment strategies.
There is evidence that 'dark adaptation' (the recovery of vision in the dark, following exposure to a bright adapting light) is a highly sensitive functional marker for early AMD. Cone dark adaptation is of particular interest to clinicians, as it can identify patients with early AMD in a relatively short recording period. I am therefore particularly interested in optimising psychophysical and electrophysiological techniques for the assessment of cone dark adaptation in early AMD, in order to maximise its diagnostic potential.
Some important outcomes of my research include:
- A range of psychophysical methods may be used to monitor the rapid changes in threshold that occur during cone dark adaptation.
- Consideration of the age-related changes in the dynamics of cone dark adaptation will improve the sensitivity and specificity of this parameter in early AMD.
- An annulus located 12º from fixation is the optimal psychophysical stimulus for the assessment cone dark adaptation in early AMD (figure 1).
- A pre-adapting intensity of 84% cone photopigment allows cone dark adaptation data to be obtained in the shortest timeframe, without compromising the integrity of the data obtained.
Reading has been reported to be the most common reason for people with AMD to seek rehabilitation. For these individuals, and others with untreatable central visual loss, the provision of eccentric viewing training and the prescription of low vision aids are important rehabilitative strategies. Eccentric viewing is an adaptive strategy used to compensate for central vision loss, in which relatively healthy paracentral areas of the retina are used to fixate objects. Recently, I was involved in a systematic review of literature that highlighted the lack of high quality evidence regarding the effectiveness of eccentric viewing training in individuals with central vision loss. Clearly, there is an urgent need for robust clinical trials to establish the true potential of eccentric viewing training. I am currently working with the EFFECT trial (Eccentric Fixation from Enhanced Clinical Training) team at the Institute of Ophthalmology, University College London. This ongoing Randomised Controlled Trial aims to determine whether the functional benefit Eccentric Viewing training confers to people with AMD, in addition to the dispensing of low vision aids alone.
- Margrain (PI) & Gaffney, £5642, "Net Mobility", The Guide Dogs Association for the Blind, 2013
- Gaffney, £700, "Avastin Survey", The Macular Society, 2012
- Gaffney, £400; Travel Grant, College of Optometrists, 2012
Professor Gary Rubin, Institute of Ophthalmology, University College London, EFFECT trial (Eccentric Fixation from Enhanced Clinical Training)