Hjortdal J O, Haaskjold E, Sørensen K E, Bjerknes R
Department of Ophthalmology, Arhus University Hospital, Denmark.
Acta Ophthalmol (Copenh). 1993 Feb;71(1):44-50. doi: 10.1111/j.1755-3768.1993.tb04958.x.
Local epithelial proliferation in corneal, limbal, and conjunctival rat epithelium was investigated during organ culture of corneo-scleral shells, by relating the number of tritium labelled cells to the total number of cells (labelling index). The changes in labelling index after a mechanically induced central corneal abrasion were also studied. Local labelling indices were measured 2 h, 1, 2, 4 and 7 days after incubation. The average labelling index increased in un-abraded specimens 4-fold after 4 days of incubation, while the total number of cells only decreased 30-50%. In eyes with a central corneal abrasion the labelling index increased 10-fold in the surrounding epithelial cells after 1 day. The labelling index of the limbal and conjunctival epithelial cells increased to the same extent after 2 days of incubation. The finding of a reduced total number of cells and an increased cell proliferation in un-abraded eyes may be explained by increased loss of mature cells normally producing growth-inhibitory substances (chalones). Alternatively, the culture medium may contain an excess of growth-stimulatory substances. The results also suggest that the proliferative response spreads in a centrifugal direction during in vitro healing of a central corneal abrasion.
