An Electron-microscopic study of the rat iris after laser sphincterotomy

• Main Authors: Mei Lin Peng, 彭美玲
• Other Authors: K'O Kaung Liao
• Format: Others
• Language: zh-TW
• Online Access: http://ndltd.ncl.edu.tw/handle/93102794287100864219

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.