Abstract

Background: Neurofibromatosis type 1 (NF1) is a common autosomal dominant disorder caused by mutations in the NF1 gene, often diagnosed using the National Institutes of Health (NIH) criteria. Recently, choroidal nodules detected via near-infrared reflectance (NIR) imaging have been proposed as a diagnostic marker. However, their prevalence in pediatric populations remains unclear, necessitating further investigation.
Methods: This study was conducted at King Fahd Armed Forces Hospital, recruiting patients diagnosed with NF1 based on NIH criteria. High-resolution spectral-domain optical coherence tomography with NIR imaging was used to assess choroidal structures. Choroidal abnormalities, including choroidal nodules, were documented and analyzed across age groups.
Results: A total of seven NF1 patients (four pediatric, three adult) were included. Choroidal nodules were absent in all pediatric cases (0/4) but present in all adult cases (3/3). Lisch nodules were absent in the youngest pediatric patient but present in all others. Cutaneous features such as café-au-lait macules and axillary freckling were consistent across all ages, while systemic manifestations varied.
Conclusion: Our findings have shown that there is an age-related trend in the detection of choroidal nodules in NF1 patients, with their absence in pediatric cases raising questions regarding their potential as an early diagnostic tool in NF1. The presence of delayed melanocytic maturation and limitations in imaging techniques may be contributing factors to this discrepancy. Although choroidal nodules have shown their potential as a diagnostic tool in adult NF1 patients, conventional NIH criteria and neuro-imaging have shown to be more useful in diagnosing NF1 in early childhood.

Key words: Neurofibromatosis type 1 (NF1), choroidal nodules, Lisch nodules, optic pathway glioma, near-infrared reflectance.