A scanning ocular spectrofluorophotometer.

We describe an instrument called a scanning ocular spectrofluorophotometer (SOSF) that measures fluorescence in a two-dimensional cross-section through the anterior chamber and cornea and provides the ability to change excitation and emission wavelengths rapidly. The output of a xenon arc lamp is filtered by a diffraction grating monochromator which has a bandpass of 4 nm and a range of 400 to 800 nm. Light emitted from the fluorophore is filtered by a variable wavelength interference filter which has a bandpass of approximately 11 nm and a range of 400 to 700 nm. To demonstrate the versatility of the instrument, we measured the spectra of fluorescein, fluorescein glucuronide and rhodamine B in the anterior chambers and corneas of pigmented rabbits after topical administration. We also measured simultaneously and independently the redistribution and disappearance of a mixture of fluorescein-labeled dextran and rhodamine B after intracameral injection. Rhodamine B was very rapidly absorbed by the cornea and lens while fluorescein-dextran was not measurable in the cornea before 4 hr. The SOSF provides a means of carrying out spectrofluorophotometry in the living eye and carrying out kinetic experiments which would otherwise be awkward or impossible.