Temporal contrast sensitivity: A potential parameter for glaucoma progression, especially in advanced stages

Abstract

INTRODUCTION. Previously it could be shown that temporal contrast sensitivity is affected by glaucoma and maximally influenced after 25-Hz adaptation in normals. This study investigated different kinds of 25-Hz temporal contrast adaptation on TCS in patients with ocular hypertension, preperimetric primary open-angle glaucoma, and perimetric open-angle glaucoma. Additionally, correlations of measured data with parameters of glaucoma diagnostic were done and assessed for the potential use of TCS as a parameter for glaucoma progression. MATERIALS AND METHODS. One hundred and four subjects were included: 44 normals, 14 ocular hypertensions, 11 preperimetric primary open-angle glaucomas, and 35 perimetric open-angle glaucomas. Using the Erlangen Flicker Test, temporal contrast sensitivity was measured without adaptation, after pre-adaptation and after pre- and re-adaptations at 25 Hz. Reliability analyses were done. RESULTS. All test strategies showed high reliability (a-Cronbach’s > 0.86). In normals, age-dependency of temporal contrast sensitivity without adaptation (p = 0.052) and after pre- and re-adaptation (p = 0.008) was observed. Temporal contrast sensitivity is significantly reduced after pre-adaptation for all subjects (p < 0.001). Reduction of temporal contrast sensitivity after pre- and re-adaptations was significant in all groups (p < 0.001), but it was smaller than after single pre-adaptation (p < 0.001). Temporal contrast sensitivity without adaptation was significantly reduced in patients with perimetric glaucoma (p = 0.040) but not in patients with ocular hypertension and preperimetric glaucoma. Correlation analyses yielded a significant correlation between temporal contrast sensitivity without adaptation and mean defect (p = 0.003, r = –0.329), loss variance (p = 0.027, r = –0.256), and retinal nerve fibre layer thickness (p < 0.001, r = 0.413) for all subjects and between temporal contrast sensitivity after pre-adaptation and mean defect (p = 0.045, r = –0.239). CONCLUSIONS. Temporal contrast sensitivity seems to be affected in perimetric glaucoma with an overall reduction after adaptation. Significant correlations of temporal contrast sensitivity with perimetric and morphologic parameters offer new aspects of its potential use as a glaucoma progressions marker, especially in advanced stages when perimetric diagnosis is limited.