Non-invasive optical interrogation of the ocular anterior chamber

Ophthalmic drug research and ocular diagnostics is hampered by an inability to perform continuous sampling of the aqueous humor contained within the anterior chamber by paracentesis is technically problematic and is associated with the use of local or general anesthesia. Moreover, sampling by direct injection exposes the eye to the risk of infection. We report results obtained from an optical instrumentation technique which is concerned with the direct and non-invasive measurements of optical scattering, absorbance and fluorescence produced in the aqueous humor by various compounds, thus avoiding the need for direct sampling. Light scatter in the anterior chamber arises from particulate matter, such as cell debris and chemical precipitates following eye surgery. Absorbance is caused by the presence of materials such as haemoglobin, or results from the penetration of drugs such as hydroxyquinolines applied to the cornea. Fluorescence can be used to provide a sensitive measurements of fluoroquinolines in the anterior chamber.