APOPTOSIS OF THE MAMMALIAN RETINA AND LENS

Although retinal neurons usually last the entire lifetime of an indivi dual, many innate genetic and developmental errors and external stimul i can reduce their longevity leading to loss of visual acuity or blind ness. Similarly, the lens, largely composed of denucleated fiber cells must remain transparent for life if vision is to remain clear. Apopto sis of retinal neurons and newly generated lens fiber cells contribute s to retinal degeneration and cataract formation, respectively, in bot h humans and experimental mammals. The apoptosis is triggered by many stimuli in addition to inherited mutations and may be amenable to phar macologic amelioration. These studies not only provide new clinical in sights but also the opportunity to investigate the molecular pathways leading to apoptosis in an organ that is not required for survival. Th e eye, becomes, therefore, an important organ for evaluation of theori es of apoptosis in vivo.