Intravitreal injection of cephaloridine in the treatment of endophthalmitis

Ocular toxic effects of intravitreal injection of cephaloridine in rabbits was evaluated, and none were produced in doses of 0.25 mg or less. Clinically, intravitreal injection of cephaloridine in doses of 5 mg or more produced small punctate hemorrhages in the vascularized portions of the rabbit retina within two days. With doses of 2.5 mg or less, no clinical changes were seen during the two weeks of observation. Histologically, one day following intravitreal injection of 0.5 to 10 mg of cephaloridine there was clumping of the outer segments of the photoreceptors and destruction of the retinal pigment epithelium. Ten milligrams of cephaloridine intravitreally injected caused definite electroretinogram (ERG) changes ten minutes after injection. After 24 hours, the ERG was extinguished. An experimentally induced Escherichia coli endophthalmitis was successfully treated after six hours by intravitreal injection of cephaloridine.