|Title||"A PILOT STUDY OF A PREFERENTIAL LOOKING CONTRAST SENSITIVITY TEST FOR INDIVIDUALS WITH VISION AND/OR MULTIPLE IMPAIRMENTS"|
|Author, Co-Author||Jacqueline Pokusa, Barry Kran, Li Deng, D. Luisa Mayer|
|Abstract|| PURPOSE: Develop a test of contrast sensitivity (CS) for individuals with visual impairments using preferential looking (PL).
METHODS: A face-like stimulus of low spatial frequency that is identical when rotated 180 degrees is printed on 10 cards with contrasts between 89% and 1% and used in a PL procedure (PL-CS). Comparisons were made between PL-CS and Pelli-Robson CS chart (PR-CS) tests and analyzed in terms of high contrast visual acuity in 16 adolescent students in the Perkins Deaf-Blind Program (n=26 eyes) (LV) and 20 adult optometry students (n=20) (AO). Vision was “degraded” in the AO group using Bangerter filters. Scoring criteria were the same in each group.
RESULTS: In the LV group: CS measured with PL-CS and PR-CS tests was at the highest level (means 1.96, 1.93) for those with VA of 0.7 logMAR or better (n=12) and moderately reduced for those with poorer VA (means 1.66, 1.72) (n=14); PL-CS and PR-CS did not differ on average; PL-CS was slightly lower than PR-CS only in the LV group with poorer VA. Using the same VA criteria for the AO group degraded condition no such CS reduction was found: either for VA logMAR 0.7 or better (means 1.48, 1.60) (n=16) or VA logMAR worse than 0.7 (means 1.63, 1.59) (n=4). For the AO group, PL-CS and PR-CS did not differ on average; and PL-CS was lower than PR-CS in the better VA group. Based on Bland Altman plots, variability was high for both LV and AO groups.
Our pilot study suggests that PL-CS is a feasible test for individuals with low vision and CS results agree on average with PR-CS in the LV group. Reasons for the Bland Altman variability in comparison of CS tests require further study; possible explanations are based upon differences in CS stimulus features and tasks. The Bangerter filter “degraded” condition did not yield similar results for CS in the AO group with worse VA; this may be attributable to the small N, or it may indicate it is not a good model to simulate low vision.
NECO internal research funding partially supported this work.
|Affiliation of Co-Authors|