Abstract
Abstract: :
Purpose: The principal lesions in age–related macular degeneration (AMD) preferentially affect the macula for reasons that are not entirely understood. Inflammatory processes have been noted in early and late AMD, and it is plausible that macular–peripheral differences in the expression of proinflammatory molecules could place the macular region at higher risk than the periphery for immune–mediated injury in AMD. Since circulating leukocytes are targeted to tissue spaces by adhesion molecules such as ICAM–1 (CD54), we sought to evaluate ICAM–1 expression in macular and peripheral regions of human eyes. Methods: Sections of sucrose embedded human donor eyes that included the macula and ora serrata were evaluated for ICAM–1 immunoreactivity with monoclonal and polyclonal antibodies. Morphometric analyses of anti–ICAM–1 labeling intensity in the choriocapillaris were performed using Image J software on a series of temporal punches from 3 eyes. Results: ICAM–1 labeling of the macular choriocapillaris was typically more intense than in the peripheral choroid in human donor eyes. Morphometric measurements confirmed a significant macular–extramacular difference (p <.02). The opposite pattern was noted in the external limiting membrane, which exhibited more intense labeling in the far periphery than in the macula. Conclusions: The regional differences in ICAM–1 distribution in the choriocapillaris may impart greater susceptibility of the macula to immune cell–mediated damage in AMD, and/or may suggest a greater general pro–inflammatory challenge in the macular as compared with the extramacular choroid.
Keywords: choroid • age-related macular degeneration • inflammation