Letter Contrast Sensitivity Vision Measurement Evaluation

  • Research type

    Research Study

  • Full title

    Letter Contrast Sensitivity Testing Validation in a Young Presbyopic Phakic Population

  • IRAS ID

    291587

  • Contact name

    Michel Guillon

  • Contact email

    mguillon@otg.co.uk

  • Sponsor organisation

    Cccular Technology Group - International

  • Duration of Study in the UK

    0 years, 2 months, 28 days

  • Research summary

    In clinical practice the level of vision is measured by reading black letters on a white background under bright light. This method does not represent the vision needs in everyday life when the contrast (e.g. print) is not 100% and the light is variable (e.g. low light night time). In clinical research we need to precisely measure vision under the full range of conditions present throughout the day otherwise we overestimate the performance of new modes of vision corrections (e. g. new spectacles, contact lenses or intra-ocular lenses).
    Several tests, called Contrast Sensitivity (CS) tests measure vision using targets of different contrasts and so under daytime and night time light conditions. Most of the tests use complex patterns that the patients need to identify, these test are difficult for naïve observers and recently several tests have instead used letters of different contrasts instead of pattern.
    The objective of the study is to identify how reliable and easy are the pattern vs. the letters tests in order to include the most suitable in future clinical studies needing precise vision measurement.
    The study will involve the participants to be tested twice over a short period of time and the results of the two sets of measurements being compared: the test with the smallest difference will be considered the best.
    The study will be carried out with presbyopic (people needing different distance and near vision correction) participants as most of the spectacles, contact lenses and intraocular lenses requiring precise vision measurement validation are in this group.

  • REC name

    East of England - Cambridge South Research Ethics Committee

  • REC reference

    20/EE/0276

  • Date of REC Opinion

    18 Jan 2021

  • REC opinion

    Further Information Favourable Opinion