| Summary: | 碩士 === 中山醫學院 === 醫學研究所 === 84 === In rats,laser sphincterotomy causes pupil dilatation
immediately. We studied the iris and ciliary ganglion responces
to Q-switched Nd:YAG laser that applicated to the iris in
anesthetized rats,and a little retrograde degeneration was
found on some ciliary ganglia. A total of 14 eyes of 7 Wistar
strain rats were examined. Seven right eyes of these rats that
received Nd:YAG sphincterotomy were grouped as experimental
ones, their intact left eyes were grouped as control ones. On
the 1st,3rd,5th,6th ,9th,10th,13th day after laser treatment,
the rats were sacrificed and their ciliary ganglia were
prepared for light and electron microscopic examination. In the
control group of our study, the light reflex of pupil remained
intact, the section of iris revealed 5 normal tissue layers
under light microscope and normal architecture under scanning
electron microscope.The ipsilateral ciliary ganglion of the
control group localized at 2 sites: one aggregated on the optic
nerve sheath,the other outside the optic nerve sheath. The
neurons of the ciliary ganglion are normal in morphology. In
the experimental group, the pupils dilated immediatelyaftwer
laser treatment and no prominent light responses in all 7 right
eyes. Under scanning electron microscopic observation,the pupil
margin became more smooth than the control group,loose stromal
tissue was found beneath the wound. Under transmission electron
microscopic examination of the ciliary ganglions,some
retrograde degeneration was noted from the 6th day,and became
more promunent on the 13th day. From our study, iris
sphincterotomy with Nd:YAG laser could induce retrograde
degeneration of the ipsilateral ciliary ganglion.
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