Nonsteroidal anti-inflammatory compounds (NSAIDS) have been used since 1763, when Edward Stone described the therapeutic properties of an extract of willow bark upon ague. Although almost four centuries have passed since the first medical use of aspirin and more than four decades since its use for ocular conditions (Gifford 1947; for review see Sears 1974; Leopold and Murray 1979), the mechanism of the anti-inflammatory action of NSAIDS has yet to be clarified. The strong influence of these drugs on the phenomena of fever, pain, and inflammation, taken together with the known undesirable side effects of steroids, has made them of prime interest in ophthalmic therapeutics (Leopold and Murray 1979).