Senile macular degeneration. The involvement of giant cells in atrophy of the retinal pigment epithelium.

Senile macular degeneration (SMD) is a leading cause of registered blindness in the United States and other Western countries. Loss of central vision develops as a result of atrophy of the retinal pigment epithelium or subretinal neovascularisation. The histopathology of the atrophic form of SMD has not been extensively studied. This paper illustrates at the light and electron microscope level the involvement the atrophic form of SMD. Additional features including pigment clumping and detachment of the retinal pigment epithelium at the advancing edge of the lesion are illustrated. Giant cells and MPS cells are typical features of granulomatous inflammation, and results suggest that they may play a role in the pathogenesis of SMD.