Evaluation of Iterative Amsler Grid (IAG) test of visual distortion

• Research type

  Research Study

• Full title

  Evaluation of feasibility, validity and reliability of the Iterative Amsler Grid (IAG) for Quantification of Visual Distortion

• IRAS ID

  85590

• Contact name

  Edward Doyle

• Contact email

  edward.doyle@nhs.net

• Sponsor organisation

  Torbay Hospital Research and Development Department

• Eudract number

  N/A

• Research summary

  The principal objective of this study is to see whether a new computerized test called the Iterative Amsler Grid (IAG) can be used to measure and quantify distorted vision in patients with common eye conditions such as epiretinal membrane or age-related macular degeneration. This would allow us in future to monitor the amount of distorted vision that patients perceive and to demonstrate the effects of treatments (medical, laser or surgical).
  There is no recognised or reliable means of measuring and quantifying distorted vision. Currently a subjective test of distortion called the Amsler grid exists which consists of a black grid on white paper. The patient looks at the centre of the grid and describes any areas on the grid that are distorted. The patient can use a pen to mark affected areas onto the grid. Our new computerised test is based on the Amsler grid but can be deformed by the patient on the computer screen enabling recording and measurement of the distortion.
  Initial feasibility testing has already taken place at Holloway University Psychology department with normal subjects (to see if they perceive an undistorted pattern as appearing undistorted and also to see how they straighten out a “pre-distorted“ pattern) and also with a small number of patients with wet macular degeneration contacted by researchers there through the Macular Disease Society. We would like to ask patients to try the test. In order to validate the test we would need to study patients with distorted vision with physical retinal abnormalities that are consistent with their symptoms, and to correlate retinal findings with the pattern of distortion detected by the IAG. With these same subjects test-retest variability would be determined with confirmation of stable anatomical distortion or changing distortion at different time periods using objective photography/scanning that patients would undergo routinely in eye clinic.

• REC name

  West Midlands - Black Country Research Ethics Committee

• REC reference

  14/WM/0184

• Date of REC Opinion

  23 May 2014

• REC opinion

  Favourable Opinion