Choroidal abnormalities in neurofibromatosis type 1 with non-invasive infrared imaging
- Correspondence to: Fumihiko Mori, MD, PhD, Department of Ophthalmology, Asahikawa Medical College, Midorigaoka Higashi 2-1-1-1, Asahikawa 078-8510, Japan; morinao{at}d5.dion.ne.jp
- Accepted 5 October 2001
Retinal abnormalities have been reported worldwide in patients with neurofibromatosis type 1.1–3 However, there have been few reports of choroidal abnormalities.4 We report a patient with choroidal abnormalities, associated with neurofibromatosis type 1, using a scanning laser ophthalmoscope (SLO).
Case report
A 37 year old woman presented for an examination with hard contact lenses. Her best corrected visual acuity was 20/20 in both eyes. A diagnosis of neurofibromatosis type 1 was made on the basis of multiple cafe au lait spots, plexiform neurofibroma, and Sakurai-Lisch nodules in the iris in both eyes. The conventional ophthalmoscopic and biomicroscopic fundus examinations were unremarkable. A general medical examination showed no abnormalities except signs of neurofibromatosis type 1. SLO examination showed no abnormalities with a helium-neon laser (633 nm) and regions of multiple, bright patches with infrared imaging (780 nm) using the direct confocal mode4 (Fig 1) and dark patches with the indirect mode5 (Fig 2) at the corresponding regions in the posterior pole in both eyes. There were no scotomas in those regions using SLO microperimetry.
SLO image of the right eye using the infrared direct confocal mode.
SLO image of the right eye using the infrared indirect mode.
Comment
In this case, we observed choroidal abnormalities in a patient with neurofibromatosis type 1. The conventional fundus examination, including biomicroscopic examination and fundus colour photography, did not show remarkable changes. However, the SLO examination showed regions of bright patches with infrared imaging using the direct confocal mode and dark patches using the indirect mode at both posterior poles. Infrared light penetrates the retina into the choroid more than visible light.6 Therefore, the bright patchy regions seen with confocal infrared imaging and the absence of such regions under helium-neon light examination indicates that the patchy regions are of choroidal origin, as reported by Yasunari and colleagues.4 In addition, we observed dark patchy regions in the corresponding area using the indirect mode of infrared imaging (which also can obtain images of the deeper retinal layers non-invasively) instead of using indocyanine green fundus angiography. Yasunari and colleagues reported that choroidal abnormalities (100%) occurred more frequently than plexiform neurofibroma (29%) and Sakurai-Lisch nodules in the iris (76%).4 They also reported that bright patchy choroidal regions should be a new diagnostic criterion for neurofibromatosis type 1. The non-invasive SLO examination with confocal and indirect infrared imaging may be useful in the diagnosis of patients with neurofibromatosis type 1.
Footnotes
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The authors have no proprietary interest in any aspect of this report.
