Structural proteins of the neonatal and adult lamina cribrosa
J. C. Morrison, J. A. Jerdan, M. E. Dorman and H. A. Quigley
Glaucoma Service, Wilmer Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205.
Optic nerve heads from three premature infants and six adults were studied
immunohistochemically to compare the extracellular proteins in the lamina
cribrosa of young and old human eyes. In both age groups, antibodies to the
basement membrane components laminin and collagen type IV were associated
with blood vessels and laminar beam margins. In the adult eyes,
interstitial collagen types I and III were heavily distributed within the
laminar beams. Antibodies to fibrillin, the microfibrillar portion of
elastin, labeled discrete, heavy bands oriented longitudinally within these
beams. The beams of the neonatal lamina cribrosa contained much less
interstitial collagen, with a predominance of collagen type III. Neonatal
elastic tissue bands were less numerous and distinct within the laminar
beams. These biochemical differences between the young and old lamina
cribrosa may, in part, explain different clinical behaviors of the optic
nerve head in congenital and adult glaucoma.
