Boevé M H, van der Linde-Sipman J S, Stades F C, Vrensen G F
Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, University of Utrecht, The Netherlands.
Invest Ophthalmol Vis Sci. 1990 Sep;31(9):1886-94.
This report provides transmission electron microscopic observations on the early pathogenesis of persistent hyperplastic tunica vasculosa lentis/persistent hyperplastic primary vitreous (PHTVL/PHPV) in affected canine fetuses at days 28-44 postcoitum. The retrolental tissue by which this anomaly is characterized consists of loosely arranged fibroblasts in a randomly oriented meshwork of collagenous fibrils. Some of these cells contain melanosomes at day 44. In one day-44 eye, cells of neuroectodermal origin (Müller cells; fibrous astrocytes) were observed. From day 37 onward, the posterior subcapsular part of the lens contains rounded, increased intercellular spaces, resembling vacuoles, which deform the shape of the lens fibers. The posterior lens capsule develops normally until day 30. From day 35 onward the capsule has an amorphous ultrastructure, as opposed to the clearly laminated ultrastructure in reference eyes at day 35. In addition, the capsule's thickness increases until day 35, and, instead of growing thicker, decreases thereafter. Based on these results, it is hypothesized that a primary metabolic disorder in the lens fibers, subsequently leading to the formation of an abnormal posterior lens capsule, constitutes the primary defect in the sequence of events leading to PHTVL/PHPV.
本报告提供了对交配后28 - 44天受影响犬胎儿持续性增生性晶状体血管膜/持续性增生性原发性玻璃体（PHTVL/PHPV）早期发病机制的透射电子显微镜观察结果。该异常特征性的晶状体后组织由松散排列的成纤维细胞组成，这些成纤维细胞位于随机排列的胶原纤维网中。在44天时，其中一些细胞含有黑素小体。在一只44天的眼睛中，观察到了神经外胚层起源的细胞（穆勒细胞；纤维性星形胶质细胞）。从37天起，晶状体后囊下部分含有圆形的、细胞间隙增大，类似空泡，使晶状体纤维的形状变形。晶状体后囊在30天前发育正常。从35天起，该囊具有无定形超微结构，与35天对照眼清晰分层的超微结构不同。此外，囊的厚度在35天前增加，此后不再增厚反而变薄。基于这些结果，推测晶状体纤维中的原发性代谢紊乱，随后导致异常晶状体后囊的形成，是导致PHTVL/PHPV一系列事件中的主要缺陷。
