Contrast Sensitivity Measurement Validation Testing Program
Research type
Research Study
Full title
Contrast Sensitivity Measurement Validation Testing Program-Phase 1 – Test Resolution Determination
IRAS ID
359150
Contact name
Michel Guillon
Contact email
Sponsor organisation
Ocular Technology Group-International
ISRCTN Number
ISRCTN15565274
Duration of Study in the UK
0 years, 6 months, 0 days
Research summary
Visual performance measurement is traditionally based upon visual acuity measurement, that is determining the smallest letters that can be read. Occasionally visual performance measurement is based upon contrast sensitivity, that is using patterns of a fixed size and determining the lowest contrast at which the pattern can be seen. Contrast sensitivity is considered to be more sensitive at detecting differences in performance between different optical designs than visual acuity. Contrast sensitivity mostly use sinusoidal patterns to be detected, such patterns being unfamiliar to people, demonstrate a significant learning effect requiring extensive participant training before they can be used to compare optical designs. OTG-i developed an electronic letter contrast sensitivity test, one of the improvements of the test is that contrast sensitivity is measured with letters of different sizes matching the sizes (spatial frequencies) of the sinusoidal tests. The repeatability (precision) of OTG-i letter contrast sensitivity test and M&S Technologies linear sinusoidal contrast sensitivity test was measured in a previous study, that demonstrated a much higher repeatability for OTG-i letter contrast sensitivity test.
The American FDA requests the testing of novel designs intra ocular lenses to include contrast sensitivity testing in multisite studies and for this prefers the use of sinusoidal targets. The criteria for acceptance being based upon how close different designs perform. The objective of the test is, therefore, to determine how sensitive is the letter contrast sensitivity test at differentiating between different optical corrections. The study will be carried out in the clinic when participants will be tested with different levels of blur produced by spectacle lenses. The study will be in two phases: i. an initial exploratory phase that will include a sinusoidal test (M+S Technologies) and a letter test (OTG-i Vision Suite) to confirm that the poor repeatability of the sinusoidal test results into poor detection; ii. in the second phase data collection will continue with the letter test to determine its sensibility to defocus.REC name
North of Scotland Research Ethics Committee 2
REC reference
25/NS/0063
Date of REC Opinion
1 Jul 2025
REC opinion
Further Information Favourable Opinion