Objective To evaluate the effects of cold provoca tion on optic dise blood flow and retinal light sensitivity of primary open-angle glaucoma (POAG) patients,and explore the relationship between the changes of optic disc blood flow and retin al light sensitivity. Methods A total 33 POAG patients (33 eyes)and 13 normal controls (13 eyes) were tested by usin g th e Heidelberg retinal flowmetry (HRF) and Topcon automatic perimeter,and the optic disc blood flow and retinal light sensitivity of POAG patients and normal cont rols were measured at normal conditions and after cold provocation. Results The mean optic disc blood flow,volume and the mean retinal light sensitivity of POAG patients decreased significantly (Plt;0.05) after cold provocation.There was a linear and significant relationsh ip between the decrease of mean optic disc blood flow and mean retinal light sen sitivity of POAG patients (r=0.615,P＜0.001). The optic disc blood flow of POAG patients with a history of migraine were more likely to r educe in response to cold provocation and reduced much more than those without such history (Plt;0.05). Conclusion Cold provocation can significantly reduce both the optic disc blood flow and retinal light sensitivity in POAG patients.A close correlation was fo und between the amount of mean optic disc blood flow decrease and the volume of mean retinal light sensitivity decline. (Chin J Ocul Fundus Dis, 2001,17:37-40)