Dosage relevance of trace PFD with toxicity in rabbit retina

Objective Through pathological and histological examination on retina to research the dosage relevance of trace PFD with toxicity in rabbit retina,and provide experimental reference basis for clinical practice.Methods Fourty eight eyes from 24 experimental rabbits were randomly divided into experimental group(36 eyes) and control group(12 eyes).The experimental one was divided into 3 groups,12 eyes in each group.The surface of rabbit retina was directly injected with 30,50,and 100 μL liquids of PFD and BSS.The conditions of rabbit retina were observed under ophthalmoscope every day after the liquid injection.The sections of retina tissue were observed under transmission electron microscope in each experimental and control groups at the 4th,7th,14th and 21th day after injection.Results All samples were normal by ophthalmoscope examination while no pathological change of retina was found at various time points .At the 4th day,none substantial damage had been made in any dosage groups by transmission electron microscope examination except for 100 μL group.Only one retina of 100 μL group showed that the space around cell nucleus broadened appreciably,slightly atactic nucleus and slightly compact cytoplasm.It showed some early changes.From the 7th day,similar pathological changes were found: damage on outer segments of light receptor and outer plexiform layer,properties changes of light receptor,forming of vesicles of inner nuclear cells,damage of ganglion cell,dying of inside retina,actions of gulping cells in retina,swallow of film plates by pigment epithelial cell of retina,and dropping of top fine hair. But the retina of control group had no pathological changes.Conclusion Trace PFD exists in eyes.There is no relevance between poisonous development of retina and remaining dosage of PFD.However,large remaining of PFD can lead to retina toxicity early.