Fundus and histopathological study of radial optic neurotomy in the normal miniature pig eye.
OBJECTIVE
To demonstrate the fundus and histopathological changes in the normal miniature pig eye after radial optic neurotomy.


METHODS
Ophthalmoscopic examinations, fundus photography, and fluorescein angiography were performed on 12 eyes that underwent radial optic neurotomy, 5 normal eyes, and 7 eyes that underwent vitrectomy (from 12 pigs in total) preoperatively and 1, 7, 14, 30, and 90 days postoperatively. These eyes were enucleated 120 days postoperatively. Sixteen eyes (of 8 pigs in total) that underwent radial optic neurotomy were enucleated 1, 3, 7, and 48 days (2 pigs each time) postoperatively. The enucleated eye sections were stained with hematoxylin-eosin, Masson trichrome, and Luxol fast blue.


RESULTS
The retina radial to the site of radial optic neurotomy darkened gradually with the increasing curvature of the major retinal arteries. The filling time intervals from the retinal artery to the retinal vein were prolonged. At the incision site, there was a loss of nerve fibers, which were subsequently replaced by collagenous tissue. No anastomotic vessels formed by the end of the study.


CONCLUSIONS
Postoperatively, the retinal circulation seemed somewhat sluggish compared with that seen preoperatively. Segmental retinal nerve atrophy eventually formed. The procedure itself may not be the sole factor for the formation of shunt vessels.


CONCLUSIONS
To date, radial optic neurotomy is controversial and persuasive animal studies are lacking. In combining fluorescein angiography with histopathological examination, this study may be somewhat helpful.
Tao
Yong
Y
Department of Ophthalmology, People's Hospital, Peking University, Beijing 100044, China.
Jiang
Yan-Rong
YR
Li
Xiao-Xin
XX
Yin
Chun-Yue
CY
Yao
Jin
J
D000818:Animals; D004195:Disease Models, Animal; D005451:Fluorescein Angiography; D005654:Fundus Oculi; D013508:Ophthalmologic Surgical Procedures; D009896:Optic Atrophy / Q000175:diagnosis; D009898:Optic Disk / Q000098:blood supply / Q000601:surgery*; D009900:Optic Nerve / Q000473:pathology / Q000601:surgery*; D012164:Retinal Diseases / Q000175:diagnosis*; D012171:Retinal Vessels / Q000473:pathology*; D013552:Swine; D013556:Swine, Miniature; D014821:Vitrectomy; D014823:Vitreous Hemorrhage / Q000175:diagnosis