[Studies on embryonal development of lamina cribrosa of human eyes]

The lamina cribrosa of 291 eyes were studied including 260 eyes taken from embryos and fetus of 7 weeks to full term and 31 eyes from infants under 1 year of age. From the observations, it is discovered that the development of the lamina cribrosa lags behind the development of the optic nerve. In the eyes taken from embryos or fetus < 4 months, only the ectodermal primordium of the lamina cribrosa is seen. The initial scleral part of the lamina cribrosa begins to be formed in the 5th month fetus. The fibrous tissue originating from the choroid and optic nerve sheath contributes the formation of the lamina cribrosa in the 8th month fetus. At this time, the morphology of the lamina cribrosa is similar to that of an adult, but the thickness of the structure is still increasing till one year after birth.