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Fundus Autofluorescence and RPE Lipofuscin in Age-Related Macular Degeneration.

Sparrow JR, Duncker T - J Clin Med (2014)

Bottom Line: SW-AF imaging is currently used in the clinical management of retinal disorders and the advantages of NIR-AF are increasingly recognized.Here we visit the damaging properties of RPE lipofuscin that could be significant when expressed on a background of genetic susceptibility.To advance interpretations of disease-related patterns of fundus AF in AMD, we also consider the photochemical and spectrophotometric features of the lipofuscin compounds responsible for generating the fluorescence emission.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Ophthalmology, Columbia University Medical Center, 635 W. 165th Street, New York, NY 10032, USA ; Department of Pathology and Cell Biology, Columbia University Medical Center, 630 168th Street, New York, NY 10032, USA.

ABSTRACT
Genes that increase susceptibility to age-related macular degeneration (AMD) have been identified; however, since many individuals carrying these risk alleles do not develop disease, other contributors are involved. One additional factor, long implicated in the pathogenesis of AMD, is the lipofuscin of retinal pigment epithelium (RPE). The fluorophores that constitute RPE lipofuscin also serve as a source of autofluorescence (AF) that can be imaged by confocal laser ophthalmoscopy. The AF originating from lipofuscin is excited by the delivery of short wavelength (SW) light. A second autofluorescence is emitted from the melanin of RPE (and choroid) upon near-infrared (NIR-AF) excitation. SW-AF imaging is currently used in the clinical management of retinal disorders and the advantages of NIR-AF are increasingly recognized. Here we visit the damaging properties of RPE lipofuscin that could be significant when expressed on a background of genetic susceptibility. To advance interpretations of disease-related patterns of fundus AF in AMD, we also consider the photochemical and spectrophotometric features of the lipofuscin compounds responsible for generating the fluorescence emission.

No MeSH data available.


Related in: MedlinePlus

An area of geographic atrophy (GA) imaged with short-wavelength (SW) and near-infrared (NIR) autofluorescence (AF) imaging. GA appears dark with both modalities. The zone surrounding GA is hyperautofluorescent in the NIR-AF image while having relatively normal SW-AF signal. When vessel landmarks are used as a guide (arrows), total lesion size appears larger in the NIR-AF image.
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Figure 7: An area of geographic atrophy (GA) imaged with short-wavelength (SW) and near-infrared (NIR) autofluorescence (AF) imaging. GA appears dark with both modalities. The zone surrounding GA is hyperautofluorescent in the NIR-AF image while having relatively normal SW-AF signal. When vessel landmarks are used as a guide (arrows), total lesion size appears larger in the NIR-AF image.

Mentions: In the presence of retinal disease such as AMD, patterns and intensities of fundus autofluorescence are notably altered [88–93]. At locations of RPE and photoreceptor cell demise (atrophy) both the SW-AF and NIR-AF signals become strikingly deficient or absent [94, 95]. These areas of atrophy can take the form of discrete spots, isolated patches or large expanses (geographic atrophy, GA, USA). Loss of the RPE cell monolayer in GA has been confirmed by OCT [96]. While GA presents as areas of darkness in both SW and NIR-AF (Figure 7), the lesion size can sometimes appear larger with either the SW-AF or NIR-AF modality [84, 97] (Figure 7). Nevertheless, the rate of increase in GA area is the same whether measured in SW- or NIR-AF images [98]. In exudative AMD, the developing neovascular lesion can be discerned in SW-AF images early on as a focal hyperautofluorescence [99]. Later the SW-AF signal is reduced within the lesion [99, 100]. In some cases the edge of the neovascular lesion exhibits increased SW-AF signal [100].


Fundus Autofluorescence and RPE Lipofuscin in Age-Related Macular Degeneration.

Sparrow JR, Duncker T - J Clin Med (2014)

An area of geographic atrophy (GA) imaged with short-wavelength (SW) and near-infrared (NIR) autofluorescence (AF) imaging. GA appears dark with both modalities. The zone surrounding GA is hyperautofluorescent in the NIR-AF image while having relatively normal SW-AF signal. When vessel landmarks are used as a guide (arrows), total lesion size appears larger in the NIR-AF image.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4358814&req=5

Figure 7: An area of geographic atrophy (GA) imaged with short-wavelength (SW) and near-infrared (NIR) autofluorescence (AF) imaging. GA appears dark with both modalities. The zone surrounding GA is hyperautofluorescent in the NIR-AF image while having relatively normal SW-AF signal. When vessel landmarks are used as a guide (arrows), total lesion size appears larger in the NIR-AF image.
Mentions: In the presence of retinal disease such as AMD, patterns and intensities of fundus autofluorescence are notably altered [88–93]. At locations of RPE and photoreceptor cell demise (atrophy) both the SW-AF and NIR-AF signals become strikingly deficient or absent [94, 95]. These areas of atrophy can take the form of discrete spots, isolated patches or large expanses (geographic atrophy, GA, USA). Loss of the RPE cell monolayer in GA has been confirmed by OCT [96]. While GA presents as areas of darkness in both SW and NIR-AF (Figure 7), the lesion size can sometimes appear larger with either the SW-AF or NIR-AF modality [84, 97] (Figure 7). Nevertheless, the rate of increase in GA area is the same whether measured in SW- or NIR-AF images [98]. In exudative AMD, the developing neovascular lesion can be discerned in SW-AF images early on as a focal hyperautofluorescence [99]. Later the SW-AF signal is reduced within the lesion [99, 100]. In some cases the edge of the neovascular lesion exhibits increased SW-AF signal [100].

Bottom Line: SW-AF imaging is currently used in the clinical management of retinal disorders and the advantages of NIR-AF are increasingly recognized.Here we visit the damaging properties of RPE lipofuscin that could be significant when expressed on a background of genetic susceptibility.To advance interpretations of disease-related patterns of fundus AF in AMD, we also consider the photochemical and spectrophotometric features of the lipofuscin compounds responsible for generating the fluorescence emission.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Ophthalmology, Columbia University Medical Center, 635 W. 165th Street, New York, NY 10032, USA ; Department of Pathology and Cell Biology, Columbia University Medical Center, 630 168th Street, New York, NY 10032, USA.

ABSTRACT
Genes that increase susceptibility to age-related macular degeneration (AMD) have been identified; however, since many individuals carrying these risk alleles do not develop disease, other contributors are involved. One additional factor, long implicated in the pathogenesis of AMD, is the lipofuscin of retinal pigment epithelium (RPE). The fluorophores that constitute RPE lipofuscin also serve as a source of autofluorescence (AF) that can be imaged by confocal laser ophthalmoscopy. The AF originating from lipofuscin is excited by the delivery of short wavelength (SW) light. A second autofluorescence is emitted from the melanin of RPE (and choroid) upon near-infrared (NIR-AF) excitation. SW-AF imaging is currently used in the clinical management of retinal disorders and the advantages of NIR-AF are increasingly recognized. Here we visit the damaging properties of RPE lipofuscin that could be significant when expressed on a background of genetic susceptibility. To advance interpretations of disease-related patterns of fundus AF in AMD, we also consider the photochemical and spectrophotometric features of the lipofuscin compounds responsible for generating the fluorescence emission.

No MeSH data available.


Related in: MedlinePlus