Human retinal function lab

Our lab investigates human retinal function in health and disease, using in vivo electrophysiology (recording the electrical responses produced by retinal neurons in response to light) and complementary approaches including retinal imaging, genetic investigation and machine learning. The retina works by generating electrical signals in response to light; these signals are processed and eventually transmitted to the brain allowing us to see. Analysing these responses can shed light on normal visual function and mechanisms of disease, particularly inherited retinal disease. Myopia (short-sightedness) appears to be driven by retinal signals: understanding retinal electrophysiology may help us understand the mechanisms of myopia development. Also, retinal signalling has similarities with processes occurring in the brain, and alterations in retinal responses could yield insight into the changes occurring in some neurological diseases. 

We are developing and testing newer electroretinography protocols, combined with mathematical modelling of responses, to investigate with greater precision, in the living human eye, processes underlying visual signalling in the retina and retinal light and dark adaptation, as well as their impairment in disease. We are also exploring the use of portable electroretinography devices in clinics to widen accessibility to such tests where they can help inform clinical care. 

Research-informed by these investigations has resulted in numerous publications. In a research letter published in the New England Journal of Medicine, we recorded retinal electrical responses following smartphone viewing, showing that the “blindness” reported by some patients was consistent with normal retinal adaptation (the letter received widespread media coverage and was number 23 of the 100 most discussed articles of 2016 https://www.altmetric.com/top100/2016/). Major sources of current funding include a £1.1 million award from the Wellcome Trust and grants from Moorfields Eye Charity. Other funding support has been from Fight for Sight, the Thomas Pocklington Trust, the Birdshot Uveitis Society and the NIHR Biomedical Research Centre at Moorfields Eye Hospital and the UCL Institute of Ophthalmology.

Key collaborators include the following:
Andrew Webster (UCL), Michel Michaelides (UCL), Gavin Arno (UCL), Pearse Keane (UCL), Chris Hammond (KCL), Pirro Hysi (KCL), Anthony Robson (Moorfields), Tony Moore (UCSF), Trevor Lamb (Australian National University), John Robson (University of Houston, University of Cambridge), Samantha De Silva (University of Oxford), Katie Williams (KCL), Moin Mohamed (St Thomas’ Hospital), Simon Petersen-Jones (MSU).

People

Principal Investigator

Professor Omar Mahroo

Current Lab Members
Post-doctoral Research Scientists

• Mr Mark Simcoe – investigating genetic epidemiology of eye diseases (co-supervisor: Dr Pirro Hysi).
• Dr Jim Bellingham – genetic investigation of inherited retinal diseases (co-supervisor: Dr Gavin Arno).
• Dr Sophie Glinton – applying machine learning methods to clinical electroretinography datasets (co-supervisor: Dr Anthony Robson).

PhD Students

• Miss Xiaofan Jiang – developing new electroretinogram protocols to monitor retinal adaptation. (Awarded distinction for MSc project exploring isolated rod and cone system responses).
• Miss Zihe Xu (based at KCL, primary supervisor: Dr Pirro Hysi) – associations between myopia-associated genetic loci and electrophysiology parameters. (Awarded distinction for MSc project on retinal light adaptation).

Research Students

• Miss Megan Margetts – electroretinogram responses in Vitamin A deficiency (received the Dodt Award at the Annual Symposium of the International Society for Clinical Electrophysiology of Vision in 2020).
• Mr Remi Rufus-Toye – investigating human cone photoreceptor light-sensitive current at early times following onset of intense backgrounds (received a Rob Clarke abstract award at the Future Physiology meeting organised by the Physiological Society in 2020).