Abstract
The development of the inner limiting membrane, inner layer of the retina and hyaloid capillaries were studied by electron microscopy from 13 days of gestation until 3 6 days after birth.
1) On the 13th day of gestation, a complete basal lamina encloses the optic cup prior to the retinal development and remains constant in its feature until 36 days after birth. It reveals that the basal laminas of the Muller cells and the pigment epithelium are continuous with one another and derived from ectodermal tissues and it was concluded that the inner limiting membrane of the retina is the basal lamina of the Muller cell.
2) The hyaloid capillaries are ramified from the hyaloid vascular system and some of them extend along the optic cup to the periphery. Endothelial cells are nonfenestrated and contain many pinocytotic vesicles especially during the 16th day of gestation and the 2nd day after birth, which are thought to function in fluid transport across the capillary wall. Their continuous basal laminas are formed on the 20th day of gestation.
3) The marginal zone of the optic cup is occupied by the basal part of the immature Muller cells on the 13th day of gestation, which contain free ribosomes, mitochondria and rough surfaced endoplasmic reticulum. During the gestation, developing Milner cells appear less dence and contaiin less organelles as compare with the mature cells. The mature Muller cell shows characteristic feature containing typical smooth surfaced endoplasmic reticulum, a large number of filaments and mitochondria. It is thought that the maturity of the Muller cell is accomplished after the 7 th postnatal day.
