Clearing of vitreous hemorrhages is variable and unpredictable in spite of measures used to accelerate absorption (von Sallmann,1 Lepri2). Crystalline trypsin in sesame oil was first studied by Hopen and Campagna (1954)3,4 in patients with various ocular conditions. Good results were noted, following its intramuscular administration, in 16 cases of extraocular trauma and in 5 patients with postoperative hyphema. In two of five patients with vitreous hemorrhages improvement was attributed to trypsin. One patient showed complete clearing in eight weeks, whereas the hemorrhage of the second was partially clear in four weeks.
The mode of action of trypsin is not certain, but various investigators have stressed the anti-inflammatory and thrombolytic effects.5,6 Following the report of Hopen and Campagna, intramuscularly administered trypsin has been tried in this hospital in a small series of patients with diabetic vitreous hemorrhages, and the results observed prompted a controlled experiment on
CHANDLER MR, ROSENTHAL E. The Effect of Intramuscularly Administered Trypsin on Blood Injected into the Vitreous of Rabbits. AMA Arch Ophthalmol. 1958;59(5):706-711. doi:10.1001/archopht.1958.00940060090010