Purpose : Age-related macular degeneration (AMD) is the leading cause of blindness in elderly people. The early form is characterized by the presence of big subretinal deposits, named drusen. While small (hard) drusen are associated with age but not with AMD, sizeable drusen are an important risk factor to develop late stage AMD, characterized by neovascularization (wet AMD) and photoreceptor and retina pigment epithelium (RPE) atrophy (geographic atrophy, GA). Others and we have previously demonstrated that late AMD is characterized by the infiltration of pathogenic mononuclear phagocytes.
To evaluate the presence of subretinal mononuclear phagocytes in human donor eyes with and without different sized drusen.
Methods : Three retina samples from macular and mid periphery from six donors were dissected stained by immunohistochemistryfor the MP-marker Iba-1. MPs were counted on whole RPE flatmounts..
Results : Subretinal Iba-1+ MPs are absent in healthy age-matched control donors, seldom present in donors with small drusen (< 63 µ) not associated with AMD, but their number was significantly increased on the RPE overlaying large drusen (> 125 µ).
Conclusions : Our experiments demonstrated MPs infiltrate the subretinal space in eyes with large drusen, associated with AMD, but not in eyes with small drusen. These findings show that subretinal MP infiltration is associated with large Drusen, an important risk factor for the development of late AMD.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.