A 2-DIMENSIONAL SCANNING OCULAR FLUOROPHOTOMETER

  • 1 January 1985
    • journal article
    • research article
    • Vol. 26  (2) , 144-152
Abstract
For certain studies of the dynamics of fluorescein in the anterior segment of the eye it would be advantageous to measure fluorescent intensity from several anatomic regions of the cornea and anterior chamber simultaneously or in rapid succession. A device called a 2-dimensional scanning ocular fluorophotometer designed and built to measure fluorescein concentration in a horizontal section through the cornea and anterior chamber is described. The 488-nm wavelength beam of an argon laser is mechanically scanned through the target area (70 .mu.W total power at the eye) and fluorescent light is measured with a photon-counting photomultiplier tube. A single anterior-posterior scan requires 100 ms and is divided into 33 sample time periods of 3 ms each. Thirty anterior-posterior scans are made within 3 s A 2-dimensional array of fluorescein concentration is reconstructed from the data. Concentrations ranging from 3 .times. 10-10 gm/ml to 3 .times. 10-6 g/ml are measured in a single scan. Examples of scans through the anterior chamber and cornea after topical and systemic administration of fluorescein are presented. These scans illustrate how this instrument can be used to measure 2 types of regional differences in fluorescein concentration, the pupillary aqueous bubble following topical administration and the radial concentration gradient in the cornea following systemic administration.