Temporal contrast adaptation in the analysis of visual function in primary open-angle glaucoma

Purpose To explore the utility of the recovery time (RT) after temporal contrast adaptation in primary open-angle glaucoma (POAG) visual function analysis, especially in severe and end-stage glaucoma, by the Erlanger Flicker Test (EFT). Methods This study included 80 POAG eyes (45 subjects) and 20 normal eyes (20 subjects). POAG eyes were divided into 5 groups. The diagnostic efficacy of the EFT was assessed, and the RT of POAG eyes at different stages was compared. The EFT results were compared with glaucomatous structure and function test results. A nomogram was developed to predict disease progression by the RT and structural indicators. Results In the normal eyes, as the test contrast increased, the RT gradually decreased. The EFT test–retest reproducibility was good, with intraclass correlation coefficient values of 0.6 ( P < 0.05) for each test contrast. At 12%, 25%, and 35% contrast, the RT in the severe and end-stage glaucoma eyes was significantly prolonged compared with the control group ( P < 0.05). The RT at different contrasts was significantly correlated with visual acuity, mean defect, mean sensitivity, and general and individual quadrant optic nerve fiber layer thickness ( P ≤ 0.001). The receiver operating curve indicated that RT 12% showed the best overall area under the curve (0.863). We included RT 25% and average optic nerve fiber layer thickness in constructing the nomogram. POAG eyes were further divided into 8 stages. According to the probability distribution, this model showed good performance for visual function analysis in advanced glaucoma. Conclusions Combined with traditional glaucomatous structural and functional parameters, the EFT can be used in the diagnosis and visual function analysis of POAG, especially for severe and end-stage glaucoma. It could be a potential test for disease staging in severe and end-stage glaucoma.