title: Choriocapillaris breakdown precedes retinal degeneration in age-related macular degeneration.
abstract: This work presents a combined light and electron microscopical approach to investigate the initial breakdown of the retinal pigment epithelium (RPE) and choriocapillaris (CC) in age-related macular degeneration (AMD). Perimacular sections of 12 dry and wet AMD eyes (82 ± 15 years) and 7 age-matched controls (75 ± 10 years) without retinal pathology were investigated. Disease progression was classified into 5 stages of retinal degeneration to investigate the concurrent CC breakdown. Special emphasis was laid on transitions where intact CC-RPE-retina complexes went over into highly atrophied areas. AMD sections showed elevated loss of photoreceptors, RPE and CC (p < 0.01), and thickened Bruch's membrane with increased basal laminar and linear deposits compared with controls. Up to 27% of the CC was lost in controls although RPE and retina were still intact. This primary loss of CC further increased with AMD (up to 100%). The data implicate that CC breakdown already occurs during normal aging and precedes degeneration of the RPE and retina with AMD, defining AMD as a vascular disease. Particular attention should be given to the investigation of early AMD stages and transitional stages to the late stage that reveal a possible sequence of degenerative steps with aging and AMD.
authors.affiliation: Section for Experimental Vitreoretinal Surgery, Center for Ophthalmology, University of Tuebingen, Tuebingen, Germany. Electronic address: antje.biesemeier@med.uni-tuebingen.de.
authors.forename: Antje
authors.initials: A
authors.lastname: Biesemeier
authors.affiliation: Section for Experimental Vitreoretinal Surgery, Center for Ophthalmology, University of Tuebingen, Tuebingen, Germany.
authors.forename: Tatjana
authors.initials: T
authors.lastname: Taubitz
authors.affiliation: Section for Experimental Vitreoretinal Surgery, Center for Ophthalmology, University of Tuebingen, Tuebingen, Germany.
authors.forename: Sylvie
authors.initials: S
authors.lastname: Julien
authors.affiliation: Cornea Bank, Center for Ophthalmology, University of Tuebingen, Tuebingen, Germany.
authors.forename: Efdal
authors.initials: E
authors.lastname: Yoeruek
authors.affiliation: Section for Experimental Vitreoretinal Surgery, Center for Ophthalmology, University of Tuebingen, Tuebingen, Germany.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Schraermeyer
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000473:pathology*; D002196:Capillaries / Q000473:pathology* / Q000648:ultrastructure*; D002829:Choroid / Q000098:blood supply*; D018450:Disease Progression; D005260:Female; D006801:Humans; D008268:Macular Degeneration / Q000473:pathology*; D008297:Male; D008853:Microscopy; D008875:Middle Aged; D055213:Retinal Pigment Epithelium / Q000473:pathology* / Q000648:ultrastructure*; D012720:Severity of Illness Index
keywords: Age related macular degeneration; Choriocapillaris; Retinal pigment epithelium; Transition between healthy and atrophied areas; Whole-section panorama images