June 2020
Volume 61, Issue 7
Free
ARVO Annual Meeting Abstract  |   June 2020
Tracking Slowed Dark Adaptation Dynamically in Vitamin A deficiency and retinal disease by electroretinogram
Author Affiliations & Notes
  • Xiaofan Jiang
    Institute of Ophthalmology, University College London, London, United Kingdom
    Ophthalmology, King's College London, London, ENGLAND, United Kingdom
  • Shaun Leo
    Institute of Ophthalmology, University College London, London, United Kingdom
    Ophthalmology, King's College London, London, ENGLAND, United Kingdom
  • Isabelle Chow
    Ophthalmology, King's College London, London, ENGLAND, United Kingdom
    Twin Research and Genetic Epidemiology, King’s College London, United Kingdom
  • Mathura Indusegaran
    Ophthalmology, King's College London, London, ENGLAND, United Kingdom
    Twin Research and Genetic Epidemiology, King’s College London, United Kingdom
  • Anthony G Robson
    Institute of Ophthalmology, University College London, London, United Kingdom
    Moorfields Eye Hospital, United Kingdom
  • Andrew R. Webster
    Institute of Ophthalmology, University College London, London, United Kingdom
    Moorfields Eye Hospital, United Kingdom
  • Christopher Hammond
    Ophthalmology, King's College London, London, ENGLAND, United Kingdom
    Twin Research and Genetic Epidemiology, King’s College London, United Kingdom
  • Omar Abdul Rahman Mahroo
    Ophthalmology, King's College London, London, ENGLAND, United Kingdom
    Institute of Ophthalmology, University College London, London, United Kingdom
  • Footnotes
    Commercial Relationships   Xiaofan Jiang, None; Shaun Leo, None; Isabelle Chow, None; Mathura Indusegaran, None; Anthony Robson, None; Andrew Webster, None; Christopher Hammond, None; Omar Mahroo, None
  • Footnotes
    Support  Wellcome Trust (206619/Z/17/Z); Fight for Sight UK (1409/10); Moorfields Eye Charity; NIHR Biomedical Research Centre at Moorfields Eye Hospital and the UCL Institute of Ophthalmology; TwinsUK receives support from the Wellcome Trust and Biomedical Research Centre based at Guy's and St Thomas' NHS Foundation Trust and King's College London.
Investigative Ophthalmology & Visual Science June 2020, Vol.61, 5053. doi:
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      Xiaofan Jiang, Shaun Leo, Isabelle Chow, Mathura Indusegaran, Anthony G Robson, Andrew R. Webster, Christopher Hammond, Omar Abdul Rahman Mahroo; Tracking Slowed Dark Adaptation Dynamically in Vitamin A deficiency and retinal disease by electroretinogram. Invest. Ophthalmol. Vis. Sci. 2020;61(7):5053.

      Download citation file:


      © ARVO (1962-2015); The Authors (2016-present)

      ×
  • Supplements
Abstract

Purpose : Standard full-field electroretinograms (ERGs) assess retinal function at steady state, after light/dark adaptation. We delivered dim flashes following extinction of a light background to track recovery of rod system sensitivity electrophysiologically, making recordings in control participants and patients.

Methods : Participants’ pupils were pharmacologically dilated, and ERGs were recorded using conductive fibre electrodes in response to the standard ISCEV dim flash (DA 0.01; corresponding to 0.02 scotopic cd m-2 s) delivered over 30-60 min following extinction of the standard ISCEV photopic background. Each participant was exposed to the photopic background for an additional 5 min following standard photopic testing. Flash series were repeated every 2 min, and b-wave amplitudes plotted as a function of time in the dark (normalised to final level).

Results : Eleven participants underwent the recording protocol, including 7 healthy volunteers (aged 21-82 years), a 50 year old with early onset widespread drusen, two patients (ages 42 and 49), with molecularly confirmed Sorsby Fundus Dystrophy (SFD) and a 70 year old with Vitamin A deficiency (VAD) after treatment and at varying levels of deficiency. Responses were initially of low amplitude after extinction of the background, but then recovered gradually in the dark. In all participants expect the SFD and VAD patients, recovery kinetics were broadly similar: amplitudes reached half the final level by c.10 min, and the final level at c.20 min. The VAD patient showed normal recovery following treatment, no recovery at all when markedly deficient, and a slowed recovery when more mildly deficient. The SFD patients displayed slowed recoveries, similar to that shown by the VAD when mildly deficient.

Conclusions : The protocol was well tolerated and yielded a discernible recovery curve in all participants. Slowed recoveries were seen in SFD and VAD. Although abnormalities in SFD on clinical examination are largely confined to the macula, these findings confirm delayed recovery affecting the retina as a whole, and are consistent with an “ocular vitamin A deficiency” in SFD. The protocol might have advantages over conventional psychophysical dark adaptation in being more objective and less reliant on patient concentration, and yielding recovery parameters reflecting the retina as a whole.

This is a 2020 ARVO Annual Meeting abstract.

×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×