Ebersberger A, Flügel C, Lütjen-Drecoll E
Anatomisches Institut II, Universität Erlangen-Nürnberg.
Klin Monbl Augenheilkd. 1993 Jul;203(1):53-8. doi: 10.1055/s-2008-1045648.
The ciliary muscle in man serves two different functions, namely accommodation and regulation of aqueous outflow. It is still not known whether both functions are combined or whether they can also be fulfilled independently from each other. (The latter could provide the possibility of an isolated pharmacological influence on the outflow-related function which should certainly be of use e.g. in glaucoma treatment).
To investigate the presence of functionally different muscle portions within the ciliary muscle and its relation to accommodation we have studied the ciliary muscle of various species showing no (rat, rabbit), moderate (cattle) and good (cat, tupaia glis) accommodative activities. For that purpose enzyme histochemical methods were used which are normally applied for differentiation of skeletal muscle fibers into fast phasic type II-fibres and slow tonic type I-fibres. Additionally, electron microscopical studies were undertaken to evaluate the ultrastructure of the muscle cells.
It was found that only those species showing accommodation, were characterized by slight (cattle) or pronounced (cat, tupaia glis) differences in histochemical staining and ultrastructure of muscle cells. Characteristically, the longitudinal portion showing structural affinity to the aqueous outflow system, was different from the inner reticular and circular portions showing more relation to accommodative functions.
These differences might indicate that two different functional systems within the ciliary muscle do exist which have been developed during evolution of higher accommodative mechanisms in the eye.
人类的睫状肌具有两种不同功能，即调节作用和房水流出调节。目前仍不清楚这两种功能是结合在一起的，还是彼此独立发挥作用。（后者可能提供了对与房水流出相关功能进行单独药理学影响的可能性，这在青光眼治疗等方面肯定会有用）。
为了研究睫状肌内功能不同的肌肉部分的存在及其与调节作用的关系，我们研究了不同物种的睫状肌，这些物种的调节活性分别为无（大鼠、兔子）、中等（牛）和良好（猫、树鼩）。为此，采用了通常用于区分骨骼肌纤维为快速相II型纤维和慢速紧张I型纤维的酶组织化学方法。此外，还进行了电子显微镜研究以评估肌肉细胞的超微结构。
发现只有那些具有调节能力的物种，其肌肉细胞的组织化学染色和超微结构存在轻微（牛）或明显（猫、树鼩）差异。典型的是，与房水流出系统具有结构亲和力的纵向部分，与更多与调节功能相关的内部网状和环形部分不同。
这些差异可能表明睫状肌内确实存在两个不同的功能系统，它们是在眼睛更高调节机制的进化过程中发展而来的。
