Kaufman P L
Department of Ophthalmology, University of Wisconsin-Madison, Clinical Science Center.
Trans Am Ophthalmol Soc. 1990;88:513-53.
Cynomolgus monkeys underwent unilateral PRP with xenon arc or argon or krypton laser light, employing burn intensity, size, spacing, and topography analogous to standard clinical (eg, Diabetic Retinopathy Study) treatment. Shortly thereafter, accommodative responsiveness to topical eserine and electrical stimulation of the EWN was diminished, accommodative responsiveness to systemic pilocarpine was enhanced, and the number of muscarinic receptors in the ciliary muscle was reduced in the PRP-treated eyes compared to the contralateral controls. In most instances, these parameters returned to normal over 6 to 12 weeks and the abnormalities could be induced again by another round of PRP. However, in some PRP-treated eyes, accommodative responsiveness to EWN stimulation and topical eserine remained subnormal permanently (greater than 1 year). Light and electron microscopy of the ciliary muscle and choroid confirmed the early interruption and degeneration and the subsequent regeneration of the intraocular parasympathetic nerves following PRP. These findings are similar to those seen after surgical removal of the ciliary ganglion and posterior ciliary nerves, and indicate that PRP produces an intraocular parasympathetic denervation of the ciliary muscle. This phenomenon may explain the loss of voluntary accommodation which can follow PRP in prepresbyopic humans. Three cynomolgus monkeys underwent nasal and temporal HRMP in one eye with the argon laser. One to four weeks later, accommodative responses to IM pilocarpine, topical eserine, and electric stimulation of the EWN did not differ markedly in the treated and control eyes. Five weeks after HRMP, posterior PRP was performed in the same eye, sparing the previously treated areas. One to four weeks later, accommodative responses in the PRP-treated eyes were clearly subsensitive to central electrical stimulation, but supersensitive to IM pilocarpine, compared to the contralateral controls. These findings indicate that extensive parasympathetic denervation of the ciliary muscle occurs following PRP but not following HRMP. Consequently, we infer that parasympathetic motor nerve fibers to the ciliary muscle do not travel preferentially with the LPCN, but rather travel primarily if not exclusively with the more numerous SPCN. If the monkey and the human are comparable, sparing the horizontal retinal meridians during clinical PRP so as not to disturb the LPCN will probably not help to preserve ciliary muscle function and accommodation.
食蟹猴接受了单侧视网膜光凝术，使用氙弧灯或氩激光或氪激光，采用与标准临床治疗（如糖尿病视网膜病变研究）类似的烧伤强度、大小、间距和地形。此后不久，与对侧对照相比，经视网膜光凝术治疗的眼睛对局部使用依色林和电刺激动眼神经核的调节反应性降低，对全身使用毛果芸香碱的调节反应性增强，睫状肌中毒蕈碱受体数量减少。在大多数情况下，这些参数在6至12周内恢复正常，并且通过另一轮视网膜光凝术可再次诱发异常。然而，在一些经视网膜光凝术治疗的眼睛中，对动眼神经核刺激和局部使用依色林的调节反应性永久性地保持低于正常水平（超过1年）。睫状肌和脉络膜的光镜和电镜检查证实了视网膜光凝术后眼内副交感神经的早期中断和退化以及随后的再生。这些发现与睫状神经节和睫状后神经手术切除后所见的相似，表明视网膜光凝术导致睫状肌的眼内副交感神经去神经支配。这种现象可能解释了在未老先衰的人类中视网膜光凝术后出现的自主调节功能丧失。三只食蟹猴的一只眼睛接受了氩激光进行的鼻侧和颞侧高分辨率视网膜光凝术。1至4周后，治疗眼和对照眼对肌内注射毛果芸香碱、局部使用依色林和动眼神经核电刺激的调节反应没有明显差异。高分辨率视网膜光凝术5周后，在同一只眼睛中进行后部视网膜光凝术，避开先前治疗的区域。1至4周后，与对侧对照相比，经视网膜光凝术治疗的眼睛对中央电刺激的调节反应明显不敏感，但对肌内注射毛果芸香碱超敏感。这些发现表明，视网膜光凝术后睫状肌发生广泛的副交感神经去神经支配，但高分辨率视网膜光凝术后未发生。因此，我们推断，支配睫状肌的副交感运动神经纤维并非优先与长后睫状神经一起走行，而是主要（如果不是唯一）与数量更多的短后睫状神经一起走行。如果猴子和人类情况相似，那么在临床视网膜光凝术期间保留水平视网膜子午线以免干扰长后睫状神经，可能无助于保留睫状肌功能和调节功能。
