Near-infrared fundus autofluorescence-visualized melanin in the choroidal abnormalities of neurofibromatosis type 1

Tomoko Ueda-Consolvo, Akio Miyakoshi, Hironori Ozaki, Satoshi Houki, Atsushi Hayashi

Department of Ophthalmology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan

Purpose: To report a series of three cases of neurofibromatosis type 1 examined by near-infrared fundus autofluorescence (NIR-AF) with a scanning laser ophthalmoscope and spectral-domain optical coherence tomography (OCT) to show the characteristics of choroidal abnormalities.
Methods: Retrospective case series. Six eyes of three patients were examined by conventional fundus examinations, near-infrared monochromatic light reflectance (NIR-R) and NIR-AF, OCT, fluorescein angiography, and indocyanine green angiography.
Results: All eyes showed multiple bright patchy regions in the choroid of the posterior pole with NIR-R. NIR-AF revealed high fluorescent regions of similar sizes at fundus locations identical to those shown by NIR-R. In one case, hypofluorescent regions were shown by indocyanine green angiography in the bright fluorescent region shown by NIR-AF. The other two cases showed no abnormality under conventional fundus examination or fluorescein angiography. OCT images crossing the bright patchy region showed irregular hyper-reflectivity in the choroid in two cases and hyporeflectivity in one case.
Conclusions: NIR-AF demonstrated that dense melanin was included in the choroidal nodules of neurofibromatosis type 1. The choroidal nodules showed hyper- or hyporeflectivity in the choroid on OCT, which did not affect the retinal structure.

Keywords: near-infrared fundus autofluorescence, neurofibromatosis type 1, choroidal nodule, melanin