Abstract
Purpose: :
To examine growth of the human eye globe, cornea and lens from early in gestation to late in adult life.
Methods: :
Globe antero-posterior length, horizontal and vertical diameters and corneal horizontal and vertical (white to white) diameters were measured using digital calipers (± 0.01 mm) in >650 postmortem eyes. Measurements of fully accommodated lens thickness and diameter were acquired either from retroilluminated images obtained with the lens still in the eye or with digital calipers following its removal from the eye. Additional pre- and postnatal data for some of the dimensions were obtained from the literature.
Results: :
All dimensions examined increase rapidly during prenatal development but postnatal growth differs. Growth of globe antero-posterior length, vertical and horizontal diameters and corneal vertical and horizontal diameters stops within 1 year after birth. Logistic analysis is consistent with an asymptotic prenatal growth mode and no further growth at its completion. Lens diameter increases continuously throughout postnatal life, gradually slowing, whereas lens thickness decreases from birth to late childhood before increasing again. No differences could be detected between males and females in any of the ocular dimensions.
Conclusions: :
Globe and corneal growth take place only during the prenatal growth mode and dimensions reach their maxima, shortly after birth. It is suggested that cessation of a growth stimulating signal at birth marks the end of the prenatal growth mode and that the small increases over the next year are due to cells already stimulated. Lens growth is more complex and appears to have two postnatal phases, one up till late childhood in which thickness decreases and diameter increases and the second in which both diameter and thickness increase for the rest of life. More data are required to understand these lens changes. Male and female eyes of the same age have the same globe, cornea and lens dimensions.
Keywords: aging • anatomy • development