Ultra-Structural Changes of the Chorioretina Following Intra-Vitreal Injection of Ornithine in Rabbit

ABSTRACT

The ultrastructural changes of the chorioretina following the intravitreal injection of ornithine in rabbit eyes at 1,2,4,8 week time intervals were investigated employing electron microscopy in this animal experiment. 1. 1 week after injection, swelling of the mitochondria in the cytoplasm of the pigment epithelium was seen. 2. 2 weeks after injection, phagosomes and phagolysosomes were present in the cytoplasm of the pigment epithelium and nerve elements in the inner nuclear layer disappeared and were replaced by Muller cell. 3. 4 weeks after injection, stroma of the choroid was atrophied and abundant melanocytes were aggregated, and papillary formed pigment epithelium with detachment of the retina was seen. 4. 8 weeks after injection, stromal atrophy and attenuated choriocapillaries of the choroid were present, and proliferation of the microvilli of the pigment epithelium after detachment of the retina was seen. 5. In summary intravitreal injection of ornithine in rabbits initially caused marked changes in the pigment epithelium with subsequent degeneration of the choroid and sensory retina.