Readaptation time after photostress in normal controls and glaucoma patients

Purpose. A photostress test was conducted at the subjective contrast threshold to evaluate whether psychophysical differences could be detected between chronic open-angle glaucoma patients and normal subjects. Methods. The prospective, comparative, clinical observational study included 20 patients (29 eyes) with chronic open-angle glaucoma and 20 control subjects (29 eyes). The study groups did not vary significantly in age and refractive error, but visual acuity showed a difference of 0.16. All participants underwent photostress using the Kontrastometer BA4. Results. In the glaucoma group compared with the control group, the mean contrast threshold was significantly higher and the readaptation time significantly longer. The latter correlated significantly with the papillomorphological glaucoma stage. Conclusions. In patients with chronic open-angle glaucoma,the foveal recovery time after a photostress test is significantly prolonged compared with normal subjects. It may suggest involvement of the fovea in glaucoma even if the visual acuity is 20/20.