UCL Institute of Ophthalmology

Dr Omar Mahroo

Dr Omar Mahroo

Associate Professor

Institute of Ophthalmology

Faculty of Brain Sciences

Joined UCL
16th Oct 2017

Research summary

PI for CRN portfolio study: "Recording Retinal Responses in Health and Disease"

Main research interest: Investigating retinal function in healthy subjects and impairment of function in retinal and neurological diseases using detailed in vivo human retinal electrophysiology

Retinal diseases are a major cause of blindness worldwide. The retina converts light into electrical signals, which are processed and transmitted to the brain, allowing us to see. These electrical signals can be recorded non-invasively from patients and healthy volunteers – this is termed the electroretinogram (ERG), analagous in some ways to an ECG. My research involves recording and analysing these responses, and isolating signals from different cellular populations using novel stimulus protocols and mathematical modelling techniques. We have been successful in quantifying responses from photoreceptors and bipolar cells in different states of retinal adaptation. Recently, we quantified heritability of retinal response parameters in a twin study (Bhatti et al., Ophthalmology, 2017), and we also looked at ERG changes after viewing a smartphone in the dark, showing that the resulting “blindness” reported by some patients is benign and related to retinal adaptation (Alim-Marvasti et al., NEJM, 2016).

Current areas of interest include the following:

  • Recording from patients with molecularly characterised inherited retinal dystrophies to understand the role of specific proteins in visual signalling (this will also allow development of new ways of monitoring the efficacy of new gene therapy treatments).
  • Understanding normal retinal visual signalling pathways by analysing recordings in healthy volunteers, and exploring correlation with common genetic variants and other phenotypic traits.
  • Recording from patients with neurological or neuropsychiatric conditions: the retina has similar neuronal circuitry to the brain, and so these ERGs may give insight into mechanisms of neurological impairment.

  • Understanding how myopia (short-sightedness) develops – this is driven by retinal signalling, and we are exploring whether retinal electrophysiology differs in individuals who have genetic variants that confer susceptibility to myopia (in collaboration with the TwinsUK cohort at KCL).


Royal College of Ophthalmologists
, | 2012
University of Cambridge
, | 2004
University of Cambridge
, | 2004
University of Cambridge
, | 2003
University of Cambridge
, | 1999


I completed a medical degree and PhD at the University of Cambridge, and post-doctoral work at Cambridge and the Australian National University. My PhD and post-doctoral work were under the supervision of Trevor Lamb FRS, and investigated light and dark adaptation of human rod and cone photoreceptors, and rod-driven bipolar cells using in vivo electrophysiology (Paupoo et al., J Physiol. 2000; Mahroo & Lamb, J Physiol. 2004; Kenkre et al. J Physiol 2005; Cameron, Mahroo, Lamb, J Physiol. 2006).

I worked in medical and surgical specialties in Cambridge, Huntingdon and the West Suffolk Hospital, and then commenced ophthalmic specialist training in the London Deanery in 2007. I was appointed Academic Clinical Lecturer in Ophthalmology at King's College London, joining the team of Professor Chris Hammond, in 2011, and established an electroretinography research laboratory at St Thomas' Hospital, obtaining research funding from Fight for Sight and the Birdshot Uveitis Society. During this time, I supervised three successive KCL Masters' research projects (all three students obtaining distinctions) and five undergraduate research projects at the University of Cambridge. As part of the Vision 2020 link between St Thomas' Hospital and the Muhimbili University Hospital in Tanzania, we also conducted research into retinal imaging findings in Tanzanian optic neuropathy (Kisimbi et al., Brain, 2013).

I commenced a Medical Retina fellowship at Moorfields Eye Hospital in 2014, and completed my ophthalmology training in 2015.