Interactions between light and vitreous fluid substitutes
C. Azzolini, F. Docchio, R. Brancato and G. Trabucchi
Department of Ophthalmology, San Raffaele Hospital, University of Milan, Italy.
To determine the interactions between light and vitreous fluid substitutes,
we studied the absorption and fluorescence properties of the following
fluids that are commonly used in vitreoretinal surgery: Ringer's solution,
balanced salt citrate-buffered solution, balanced salt bicarbonate-buffered
solution, hydroxypropyl methylcellulose ophthalmic solution, hyaluronate
sodium, perfluorocarbons, silicone oil, and fluorosilicone oil. The
absorption spectra for all the fluids peaked in the UV-C (reference range
<280 nm) and UV-B (reference range from 315 to 280 nm) regions of the
spectrum, with little or no absorption in the visible region of the
spectrum (from 400 to 700 nm). Emission of almost all of the fluids
occurred mainly in the 300- to 360-nm region, with fairly low-quantum
efficiency. The limited light absorption properties of the fluids calls for
caution during transpupillary and intraocular laser photocoagulation to
avoid excessive retinal damage, mainly when the laser power is increased
during treatment. Transmission of incoherent light (environmental and
ophthalmic artificial light) through highly transparent vitreous fluid
substitutes may lead in time to dangerous light exposure, particularly in
aphakic eyes. The emitted fluorescence in these fluids generates a minimal
risk of long-term damage.
