The Owl Monkey Eye Test

A highly sensitive test is required for the detection of endotoxic inflammatory substances to evaluate the purity of sodium hyaluronate. The Limulus-Lysate-Test, a highly sensitive test for pyrogens, was observed to be neither sensitive nor specific enough to detect impurities in sodium hyaluronate solutions. 

Examination procedures for the detection of cell-mediated inflammatory reactions in tissue compartments (e.g., anterior chamber, peritoneum, joint spaces) were also deemed not sensitive enough to detect this particular type of reaction mediator. 

Owl- and rhesus-monkey eyes reveal the presence of minute amounts of endotoxin introduced into the relatively large amount of aqueous humor volume along with physiological buffers. The vitreous humor of these monkey eyes is fluid and can be exchanged for test-solution with relatively little surgical trauma. 

Sodium hyaluronate solution, as well as any other fluid used in intraocular surgery, should evoke a low inflammatory reaction to the vitreous body, similar to that of physiological buffer solution, under like test conditions. 

---

Both laboratory and clinical examinations confirm that Healon , Viscoat and many other viscoelastics have no inflammatory effects when produced in the proper combinations. Specific tests (such as the owl monkey eye test) carried out prior to the release of a batch of hyaluronic acid confirm this finding in Healon , Healon 5 and Healon GV (see below). For HPMC products, implantation tests... 

---