Ultrastructure of Bruch's membrane after krypton laser photocoagulation. II. Repair of Bruch's membrane and the role of macrophages
A. Pollack, G. E. Korte, W. J. Heriot and P. Henkind
The accompanying ultrastructural study showed that ophthalmoscopically
white krypton laser photocoagulation in rats is followed by cellular
invasion causing breakdown of Bruch's membrane (BM). We have expanded these
observations, using scanning electron microscopy, transmission electron
microscopy, and high-voltage transmission electron microscopy to describe
the healing process. The repair of BM involves regenerating retinal pigment
epithelial cells and choriocapillaris (CC) that form new basement membranes
and fibroblasts that secrete collagen and elastin. The reformation of the
CC is also associated with subretinal neovascularization. The involvement
of macrophages was evident throughout the process of BM repair and
formation of new vessels. We propose that the macrophages act as a common
factor linking the diverse diseases associated with choroidal subretinal
neovascularization, deduced from our evaluation of the healing process and
the reformation of choriocapillaris.
