The occurrence of cell death during the remodelling of the chamber angle recess in the developing rat eye.

Prenatal and postnatal stages of the developing chamber angle in the rat eye were analysed qualitatively by light and electron microscopy. One eye of each of five weight-matched littermates was investigated at the following time points: prenatal days 14, 17, 18 and 21; day 0 = day of birth; postnatal days 5, 10, 15, 20, 40, 60, 100 and 200. From postnatal days 5 to 60, conspicuous amounts of necrotic cells were observed within the chamber angle area. At birth and at postnatal day 200, only a few scattered necroses were observed. Necrotic cells were found within the trabecular area, the region of Fontana's spaces and beams and the peripheral iris, the iris root, the ciliary body and the adjoining choroid. Large macrophages containing lysosomal dense bodies were found within the previously described areas and were frequently in close contact with necrotic cells. It is concluded that cell death within the developing chamber angle of the rat may represent an important event that may contribute to two morphogenetic effects: (1) the opening of large spaces of Fontana and (2) space formation within the trabecular area and uveoscleral outflow routes.