Collin H B, Collin S P
School of Optometry, University of New South Wales, Sydney, Australia.
Histol Histopathol. 1995 Apr;10(2):313-23.
The corneas of nine pipefish, Corythoichthyes paxtoni (Syngnathidae, Teleostei), five freshly fixed and four museum specimens, were examined using light and electron microscopy. In transverse section, the surface of the corneal epithelium is covered by a complex series of ridges or microplicae which extends over the conjunctiva. The cornea is considerably thicker in the centre (80 microns) than in the periphery (40 microns) and can be separated into two distinct zones. The anterior dermal cornea (23 microns) consists of two layers of epithelial cells, a thick basement membrane (0.75 micron) and numerous lamellae of collagen fibrils with a few scattered keratocytes. This layer is continuous with the conjunctiva which also contains two layers of epithelial cells and lamellae of collagen fibrils. In the juvenile, separating the two zones, is a lens-shaped (concavo-convex) region approximately 6 microns thick in the centre and about 175 microns in diameter containing a fine granular material. In the adult, this region contains both granular material and fibres. It overlies the posterior zone which consists of an anterior iridescent layer (21 microns thick) possessing numerous cell processes parallel with the corneal surface and a few collagen fibrils. The scleral cornea contains 33 lamellae of collagen fibrils without cells and a single layer of cells with several cell processes, similar in appearance to the anterior iridescent layer, which may represent a second or posterior iridescent layer. There is a thick (2 microns) Desçemet's membrane and a thin (1.5 microns) corneal endothelium. There is a spherical lens close to the posterior corneal surface and the iris contains guanine crystals anteriorly and pigment granules posteriorly.
对9条尖海龙（Corythoichthyes paxtoni，海龙科，硬骨鱼纲）的角膜进行了检查，其中5条为新鲜固定标本，4条为馆藏标本，采用了光学显微镜和电子显微镜观察。在横切面上，角膜上皮表面覆盖着一系列复杂的嵴或微褶，这些嵴或微褶延伸至结膜。角膜中央（80微米）比周边（40微米）厚得多，可分为两个不同区域。前真皮角膜（23微米）由两层上皮细胞、一层厚的基底膜（0.75微米）和许多胶原纤维薄片以及一些散在的角膜细胞组成。这一层与结膜相连，结膜也含有两层上皮细胞和胶原纤维薄片。在幼体中，分隔两个区域的是一个透镜状（凹凸）区域，中央约6微米厚，直径约175微米，含有细颗粒物质。在成体中，该区域含有颗粒物质和纤维。它覆盖在后区之上，后区由一个前部彩虹色层（21微米厚）组成，该层有许多与角膜表面平行的细胞突起和一些胶原纤维。巩膜角膜含有33层无细胞的胶原纤维薄片和一层有几个细胞突起的细胞，外观与前部彩虹色层相似，可能代表第二个或后部彩虹色层。有一层厚（2微米）的Descemet膜和一层薄（1.5微米）的角膜内皮。靠近角膜后表面有一个球形晶状体，虹膜前部含有鸟嘌呤晶体，后部含有色素颗粒。
