Choroidal laser Doppler flowmetry in healthy subjects

Objective: To evaluate normal choroidal blood flow and its relationship wit h various factors such as age, systemic blood pressure, and intraocular pre ssure (IOP). Methods: A total of 70 healthy subjects were recruited. Choroidal blood flo w was assessed using a method based on laser Doppler flowmetry (LDF) techni que. The LDF parameters of velocity, volume, and flux were obtained. The in fluence of age, mean systemic blood pressure, IOP, smoking, and sex on chor oidal hemodynamic parameters was assessed in a multiple linear regression m odel. The correlations between interocular difference in IOP and interocula r differences in the LDF parameters were assessed by means of the Pearson l inear correlation factor. Results: Velocity decreased significantly (P = .03) with advancing age of t he subjects and volume increased significantly (P = .02) with increasing IO P. Mean blood pressure, smoking, and sex had no influence on the choroidal LDF parameters. Interocular difference in IOP correlated significantly with interocular difference in volume (R = 0.34, P < .005). Conclusion: Choroidal blood flow velocity decreased with increasing age of the subjects, while the volume of moving erythrocytes decreased with lower IOP.