The toxicity of intravitreal whole blood and hemoglobin.

To determine the toxic effect of whole blood and hemoglobin on the retina, volumes of autogenous blood varying between 0.3 and 1.5 ml and various hemoglobin concentrations were injected intravitreally into speciosa monkeys. Electroretinograms were performed at the outset of the experiment and immediately before sacrifice. After six weeks the animals were killed and the eyes were processed for histologic and electron microscopic examination. Three intravitreal injections of 0.3 ml of autogenous blood administered at one-month intervals or one injection of 22.4 mg of hemoglobin did not produce a toxic effect on the retina demonstrable by light or electron microscopic examination or electroretinography. Intravitreal injection of more than 0.6 ml of whole blood or 40 mg of hemoglobin produced definite toxic effects histologically and electroretinographically. The damage found histologically correlated well with the degree of hemosiderin deposition. Explosive lesions produced by xenon are photocoagulation to induce moderate vitreous hemorrhage failed to produce toxic doses of blood within the eye. In humans undergoing vitrectomy to remove vitreous hemorrhage, the amount of whole blood recovered from vitrectomy fluid was considered nontoxic, except when the patient had massive vitreous hemorrhage or intraoperative bleeding.