Optical coherence tomography imaging of choroidal abnormalities in neurofibromatosis type 1

Multispectral Imaging Analysis of Skin Lesions in Patients with Neurofibromatosis Type 1

Neurofibromatosis type 1 (NF1) is a rare disease, affecting around 1 in 3500 individuals in the general population. The rarity of the disease contributes to the scarcity of the available diagnostic and therapeutic approaches. Multispectral imaging is a non-invasive imaging method that shows promise in the diagnosis of various skin diseases. The device utilized for the present study consisted of four sets of narrow-band LEDs, including 526 nm, 663 nm, and 964 nm for diffuse reflectance imaging and 405 nm LEDs, filtered through a 515 nm long-pass filter, for autofluorescence imaging. RGB images were captured using a CMOS camera inside of the device. This paper presents the results of this multispectral skin imaging approach to distinguish the lesions in patients with NF1 from other more common benign skin lesions. The results show that the method provides a potential novel approach to distinguish NF1 lesions from other benign skin lesions.

Choroidal Abnormalities in Pediatric NF1: A Cohort Natural History Study

The purpose of this study was to assess the long-term natural history of choroidal abnormalities (CAs) in a large pediatric neurofibromatosis type 1 (NF1) population, quantifying their progression in number and dimensions. Pediatric patients (<16 years old) affected by NF1 with a minimum follow-up of 3 years with at least one CA in one eye were consecutively recruited. Near-infrared (NIR) imaging was performed to identify CAs, which were quantified in number and size. The CAs area and perimeter were normalized for the optic disc dimensions to avoid possible bias related to the growing process of the eye. Ninety-nine eyes of 53 patients were evaluated. The CAs number, area and perimeter significantly increased during follow-up (p < 0.0001 for each parameter). The patient age at baseline was inversely correlated with the CAs number over time (coefficient = −0.1313, p = 0.0068), while no correlation was found between the patient age and CAs progression in size. In conclusion, we provide evidence that, in NF1 pediatric patients, CAs change over time, increasing both in number and dimensions, independently from the physiological growth of the eye. While the increase of the CAs number occurs particularly at an earlier age, the increase in the CAs dimensions is a slow process that remains constant during childhood.

Near-infrared imaging: an in vivo, non-invasive diagnostic tool in neurofibromatosis type 1

PURPOSE

Only a few reports in the literature have investigated the presence of ocular abnormalities in neurofibromatosis type 1 (NF-1) patients. The aim of this study was to evaluate the prevalence of ocular abnormalities in a large population of NF1 patients, focusing on the choroidal changes.

METHODS

This study was conducted on 160 consecutive patients with NF1 and 106 sex- and age-matched healthy subjects (control). Each patient underwent a complete ophthalmological examination inclusive of best-corrected visual acuity, intraocular pressure measurement, slit-lamp biomicroscopy, indirect fundus biomicroscopy, and near-infrared reflectance (NIR) retinography by using the spectral domain OCT. Moreover, all patients underwent complete dermatological exam and 1.5-Tesla MRI scan of the brain to assess the presence of optic nerve gliomas.

RESULTS

Choroidal abnormalities were detected in 97% of patients, with a positive predictive value of 100% and a negative predictive value of 96.4%. Interestingly, a small number of patients (4/160; 2.5%) showed Lisch nodules without choroidal abnormalities, whereas a larger number of patents (22/160; 13.75%) presented choroidal lesions in absence of Lisch nodules. None of the patients showed the absence of both choroidal lesions and Lisch nodules. The number of choroidal lesions increased with age (r = 0.364, p = 0.0001) and with the severity of pathology (r = 0.23, p = 0.003). Any statistically significant correlation between choroidal lesions, visual acuity, and intraocular pressure was observed.

CONCLUSIONS

NIR imaging represents an in vivo, non-invasive, sensitive and reproducible exam to detect choroidal nodules in NF-1 patients, suggesting that choroidal changes may represent an additional diagnostic criteria for NF1.

Correlations between choroidal abnormalities, Lisch nodules, and age in patients with neurofibromatosis type 1

To evaluate correlations between choroidal abnormalities, Lisch nodules, and age in patients with neurofibromatosis type 1 (NF1), we examined ten cases with NF1 using near-infrared reflectance imaging. Patients ranged in age from 4 to 39 years. The angle used for near-infrared reflectance imaging was 55°. We counted the total number of choroidal abnormalities in an area within a 55° angle centered on the fovea and the total number of Lisch nodules on the iris by slit-lamp examination. No positive correlation was found between the number of Lisch nodules and patient age (Spearman’s rank correlation coefficient ρ=0.117, P=0.7414). Choroidal abnormalities tended to increase with age (ρ=0.6150), but this difference was not statistically significant (P=0.0650). A positive correlation was found between the number of choroidal abnormalities and Lisch nodules (ρ=0.783, P=0.0267). In conclusion, choroidal abnormalities tend to increase with patient age and are correlated with the number of Lisch nodules.