PRENATAL AND POSTNATAL-GROWTH OF THE HUMAN DESCEMETS MEMBRANE

  • 1 January 1984
    • journal article
    • research article
    • Vol. 25  (12) , 1402-1405
Abstract
The origin, growth in thickness and differentiation of Descemet''s membrane was studied by light, EM, morphometric and statistical methods in 67 specimens from 12 wk of gestation to 98 yr. Descemet''s membrane is formed by 3 major processes: growth in thickness during the prenatal period, prenatal differentiation into a striated basement membrane and growth in thickness during the postnatal period. The initial step is the synthesis of an ordinary basement membrane, which is very thin and quite different in appearance from the adult Descemet''s membrane. Growth of the prenatal Descemet''s membrane then proceeds by deposition of a series of similar membrane units, which are stacked to form a lamellar structure consisting of at least 30 layers by the end of gestation. Second, during prenatal life, differentiation of the membrane leads to the formation of a striated structure through the gradual addition of short and thin cross-linking bridges separated by 110-nm intervals that are disposed in a plane perpendicular to the lamellae. The 3rd process occurs in postnatal life when the membrane continues to grow in thickness by deposition of a nonstriated, nonlamellar material posterior to the striated prenatal layer. Regression analysis suggests that prenatal growth proceeds at a rapid but variable rate best described by a sigmoid-like function of age. Postnatal growth, in contrast, proceeds in a predominantly exponential manner but at a slower pace than in the prenatal period. The low variability and large size of our set of measurements make these data especially useful for comparisons with pathologic specimens.