Morphologic changes in age‐related maculopathy

Abstract

Age-related maculopathy (ARM) is a degenerative disorder of the central part of the retina with a rising prevalence in patients 50 years of age and older, and comprises different histopathological changes. The morphologic changes in ARM are described and illustrated with light-microscopical, electron microscopical, and fundus pictures. Furthermore, the most important biochemical data are given. The most prominent aging changes in early stages of ARM are drusen and basal laminar deposit (BLD), both extracellular deposits, that are assumed to be important in the development of ARM. Drusen accumulate within Bruch's membrane, whereas BLD is present between Bruch's membrane and the retinal pigment epithelium. Although the histopathologic characteristics of the deposits are well documented, the chemical composition has only been partly resolved. Biochemical analysis of these deposits is necessary to determine the source of the deposits and to find possible ways to avoid or treat them. The late stages of ARM, geographic atrophy, and neovascular (disciform) degeneration, are called age-related macular degeneration (AMD), and result in severe and irreversible visual impairment. Since there is still no adequate therapy for the majority of people disabled by AMD, and because of the aging population resulting in even more patients with this disease, it is necessary to intensify the research on ARM in order to prevent AMD or find a therapy for it.

Age‐related macular degeneration—emerging pathogenetic and therapeutic concepts

“…Basal laminar deposits (BLamD) that accumulate between the RPE basal plasma membrane and its basal lamina (Figures 21, 24 and 28) do not appear to be specific to or 'diagnostic' for AMD; however, there is a strong relationship between macular BLamD and exudative AMD, disciform scarring, and visual loss (74,84,(108)(109)(110)(111)(112)(113)(114). BLamD-like deposits are also seen in other macular disorders with a clinical appearance similar to what is observed in AMD.…”

Relationships between clinical measures of visual function and anatomic changes associated with bevacizumab treatment for choroidal neovascularization in age-related macular degeneration

“…If SRF is resolved by treatment, the vision may not necessarily improve if there is progressive RPE and choriocapillaris atrophy, or significant fibrosis that on pathology specimens is associated with overlying full-thickness retinal atrophy. 17,18 Visual acuity, even when measured with the improved logMAR-ETDRS chart, has been criticized as a poor evaluation of vision, especially in eyes with macular disease 19 for the reasons cited above. On central field perimetry using discriminated targets, acuities in normal eyes decline uniformly in all directions from fixation to approximately 20/100 at 101 eccentricity.…”

Genetic factors of age-related macular degeneration

“…Deposition of the lipofuscin fluorophore N -retinylidene-N -retinylethanolamine (A2E) is seen in the STGD RPE layer (Weng et al, 1999). Accumulation of lipofuscin in RPE cells is observed in several forms of macular degeneration including AMD (Kliffen et al, 1997;Weng et al, 1999). Slow accumulation of lipofuscin is also seen during normal aging (Kennedy et al, 1995).…”