Flecks in Recessive Stargardt Disease: Short-Wavelength Autofluorescence, Near-Infrared Autofluorescence, and Optical Coherence Tomography

作者：Sparrow Janet R^*; Marsiglia Marcela; Allikmets Rando; Tsang Stephen; Lee Winston; Duncker Tobias; Zernant Jana

来源：Investigative Ophthalmology & Visual Science, 2015, 56(8): 5029-5039.

DOI：10.1167/iovs.15-16763

• ABCA4
• lipofuscin
• optical coherence tomography
• fundus autofluorescence
• recessive Stargardt disease
• retinal pigment epithelium
• scanning laser ophthalmoscope

PURPOSE. We evaluated the incongruous observation whereby flecks in recessive Stargardt disease (STGD1) can exhibit increased short-wavelength autofluorescence (SW-AF) that originates from retinal pigment epithelium (RPE) lipofuscin, while near-infrared AF (NIR-AF), emitted primarily from RPE melanin, is usually reduced or absent at fleck positions.
METHODS. Flecks in SW-and NIR-AF images and spectral-domain optical coherence tomography (SD-OCT) scans were studied in 19 STGD1 patients carrying disease-causing ABCA4 mutations. Fleck spatial distribution and progression were recorded in serial AF images.
RESULTS. Flecks observed in SW-AF images typically colocalized with darkened foci in NIR-AF images; the NIR-AF profiles were larger. The decreased NIR-AF signal from flecks preceded apparent changes in SW-AF. Spatiotemporal changes in fleck distribution usually progressed centrifugally, but in one case centripetal expansion was observed. Flecks in SW-AF images corresponded to hyperreflective deposits that progressively traversed photoreceptor-attributable bands in SD-OCT images. Outer nuclear layer (ONL) thickness negatively correlated with expansion of flecks from outer to inner retina.
CONCLUSIONS. In the healthy retina, RPE lipofuscin fluorophores form in photoreceptor cells but are transferred to RPE; thus the SW-AF signal from photoreceptor cells is negligible. In STGD1, NIR-AF imaging reveals that flecks are predominantly hypofluorescent and larger and that NIR-AF darkening occurs prior to heightened SW-AF signal. These observations indicate that RPE cells associated with flecks in STGD1 are considerably changed or lost. Spectral-domain OCT findings are indicative of ongoing photoreceptor cell degeneration. The bright SW-AF signal of flecks likely originates from augmented lipofuscin formation in degenerating photoreceptor cells impaired by the failure of RPE.

• 出版日期2015-7