PORTABLE OCULAR LASER-DOPPLER RED-BLOOD-CELL VELOCIMETER

A new hand-held bidirectional ocular laser Doppler system for measurem ent of red blood cell (RBC) velocity in retinal vessels and blood flow in the optic nerve head tissue and in the choriocapillaris is describ ed. Laser power at the cornea is below the maximum permissible level. The instrument is based on the well-established laser Doppler velocime try/flowmetry techniques. The optical systems for the delivery of the probing laser beam to the eye fundus and bidirectional detection of th e light scattered by the RBCs have been implemented in a portable Kowa Genesis fundus camera. lm vitro experiments demonstrate the performan ce of the instrument and in viva measurements illustrate the feasibili ty of retinal blood velocity and choriocapillaris blood flow measureme nts in awake volunteers. (C) 1997 American Institute of Physics.