Impact of eye movements on visual field testing of incongruous defects

• Research type

  Research Study

• Full title

  Impact of eye movements on visual field testing of incongruous defects post epilepsy surgery

• IRAS ID

  252775

• Contact name

  Feras Sharouf

• Contact email

  sharouffh@cardiff.ac.uk

• Sponsor organisation

  Cardiff University

• Clinicaltrials.gov Identifier

  N/A, N/A

• Duration of Study in the UK

  2 years, months, days

• Research summary

  Driving is a task that requires serial eye movements, As a consequence of epilepsy surgery, individuals are left with a visual field defect. Those individuals with a matching visual field loss will likely have a greater success at passing the standard visual field test (Esterman visual field test) due to a larger unaffected visual field in one eye. However, it is not clear whether those with these defects achieve a larger visual field due to some other adaptation
  In this study we will examine the impact of eye movements on the standard visual field test (binocular Esterman test) in those individuals with matching visual field defects and whether improved visual field performance arises from eye movements.
  A small number of each of the following categories of subjects will be recruited:
  1) Controls with no visual field defects,
  2) Patients with stable either homonymous hemianopic field defects (patients see only one side in both eyes)
  3) Patients with small, congruous central defects

  Each subject will undergo three experiments. In each experiment the central ±20° of the binocular Esterman test will be replicated on a computer display. Eye movements will be recorded throughout.
  In experiment 1, we will obtain a baseline measure of the visual field under typical eye movement behaviour.
  In experiment 2, the fixation target will be removed to measure the visual field under intentionally generated poor fixation.
  In experiment 3, the fixation target will be present but locations of the stimuli will be randomly perturbed to measure visual field under simulated eye movements.
  All experiments will take place at the School of Optometry and Vision Sciences
  Participants will wear the appropriate near correction for undertaking the test. It is expected that the entire visit will last no longer than 60 minutes.

• REC name

  South West - Frenchay Research Ethics Committee

• REC reference

  19/SW/0004

• Date of REC Opinion

  2 Jan 2019

• REC opinion

  Favourable Opinion