Two-point fluorophotometer for the human ocular fundus

A new technique for making on-line recordings of fluorescein dilution curves from two locations in the human retina has been devised. A modified Zeiss fundus camera with two optical fibers mounted in a scanning ocular collects the light emitted by fluorescein dye from two spots in the fundus. Two fiber-optic cables transmit the collected light to a photomultiplier. The detector output current is transmitted to a two-channel pulse sorter. The output signals from the pulse sorter are amplified and displayed on a two-channel recorder. Since this technique utilizes only small amounts of fluorescein, multiple measurements in the same subject are possible.