Abstract
Purpose::
To compare fundus autofluorescence of melanin elicited with near-infrared light (NIA, 787 nm) to fundus autofluorescence of lipofuscin (FAF, elicited with 488 nm) in patients with retinitis pigmentosa.
Methods::
Thirteen consecutive patients diagnosed with retinitis pigmentosa based on clinical and electrophysiological findings underwent FAF and NIA imaging using a confocal scanning laser ophthalmoscope (Heidelberg Retina Angiograph 2) with either a 300 or wide-angle field-of-view.
Results::
12/13 patients presented with areas of homogeneously increased NIA at the posterior pole. These areas showed a sharp decline of NIA intensity towards the periphery. The border of homogeneously increased NIA intensity corresponded to rings of increased FAF. In contrast to the NIA findings, FAF intensity was relatively normal central and peripheral to the ring of increased FAF. In one patient, distribution of FAF and NIA was relatively normal at the posterior pole. In all patients, the area of ophthalmoscopically preserved retinal pigment epithelium (RPE) corresponded to detectable FAF.
Conclusions::
NIA imaging provides a non-invasive in vivo visualization of RPE abnormalities. Patterns of FAF and NIA indicate different pathophysiologic processes involving lipofuscin and melanin. Based on previous histologic reports in humans with retinitis pigmentosa, NIA may visualize areas with viable photoreceptors and RPE cells, whereas FAF may correspond to preserved RPE cells. Combined FAF and NIA imaging will provide further insight in the development of retinitis pigmentosa, may serve to distinguish different genetic entities and could help to monitor future therapeutic interventions.
Keywords: retinal degenerations: hereditary • retinal pigment epithelium • macula/fovea