DESIGN AND PERFORMANCE OF A NEW OPHTHALMIC INSTRUMENT FOR DYNAMIC LIGHT-SCATTERING MEASUREMENTS IN THE HUMAN EYE

A new optical instrument for in vivo dynamic light-scattering measurem ents in the human eye is described. The instrument is based on the wel l-known dynamic light-scattering technique. Results can be obtained fr om the anterior as well as the posterior segment with high spatial res olution and sensitivity. This instrument allows, to our knowledge for the first time, in vivo measurements of dynamic light scattering to be performed in the vitreous. Interesting performance is obtained using single-mode optical fibers to guide the excitation and the scattered l ight resulting in a modular, compact system with high-beam quality and electrical insulation of the patient. The instrument demonstrates goo d safety characteristics (the optical power impinging the patient's ey e is 36 times below the maximum laser power at the cornea, recommended for intrapupil exposure by ANSI standard). To demonstrate the possibl e clinical use of this technique, in vivo measurements were made and t he results compared with the known eye pathologies. (C) 1996 American Institute of Physics.