Purpose: To assess whether intravitreal rituximab 1 mg/0.1 cc penetrates the retina of Dutch-belted rabbits.
Methods: Two right eyes of two rabbits were injected with intravitreal rituximab 1 mg/0.1 mL, and one right eye of one rabbit was injected with intravitreal tissue plasminogen activator (tPA) 12.5 microg/0.1 mL, as a protein control. The three left eyes received no intravitreal injections. The rabbits were killed; the eyes were enucleated and immediately frozen at -80 degrees C. Rituximab was detected using rabbit antihuman IgG (whole molecule) peroxidase conjugated antibody. tPA was detected using an antihuman IgG with a sheep antihuman tPA antibody conjugated with peroxidase.
Results: There was staining in all retinal layers of the two eyes injected with intravitreal rituximab, and no staining of the retina in the eye injected with intravitreal tPA. The three control eyes showed no staining in any retinal layer.
Conclusion: Intravitreal rituximab at a dose of 1 mg/0.1 cc penetrates the retina of Dutch-belted rabbits while the control intravitreal tPA at a dose of 12.5 microg/0.1 cc does not.