Abstract
Purpose :
To assess the changes in neural transfer function (NTF) with the addition of glare in young healthy subjects.
Methods :
We recruited 46 young (20-30 years old), healthy subjects. Aberrations were measured using a Topcon KR1W on a 4mm pupil size. Contrast sensitivity with and without glare was assessed with a Takagi CGT-1000. We calculated contrast sensitivity function (CSF) by interpolation and obtained the NTF with and without glare by dividing the CSF by the modulation transfer function derived from aberrations. We calculated a metric to assess the change induced by glare. We divided the integral of the NTF with glare by the integral of the NTF without glare. A ratio above 1 indicates a better NTF with glare, and a ratio below 1, a worse NTF with the presence of glare.
Results :
Out of the 46 subjects, 17 exhibited a ratio of NTF above 1, meaning their NTF was better in the presence of glare. The others obtained a ratio below 1, as we hypothesized, since glare should decrease performance. We checked the ratio of the CSF integrals with glare and the CSF integral without glare and also obtained ratios above 1 for the same subjects. Therefore, training effects might explain the subjects who obtained a ratio above 1 for their NTF.
Conclusions :
Strong variations of NTF changes were observed between subjects. Some subjects exhibit a better NTF with glare while others do not. More tests are required to explain the results we obtained.
This is a 2020 ARVO Annual Meeting abstract.