Purpose The aim of this study was to provide a classification of the different retinal vascular arrangements in neurofibromatosis 1 (NF1), with appropriate qualitative and quantitative information.

Methods This study was conducted on 334 consecutive patients with NF1 and 106 sex-matched and age-matched healthy control subjects. Each patient underwent a comprehensive ophthalmological examination inclusive of near-infrared reflectance retinography by using the spectral domain Optical coherence tomography (OCT), a complete dermatological examination and 1.5 T MRI scan of the brain to assess the presence of optic nerve gliomas. To evaluate the predictability and the diagnostic accuracy of our identified retinal microvascular arrangements, we calculated the diagnostic indicators for each pattern of pathology, with corresponding 95% CI. In addition, we evaluated the association between the microvascular arrangements and each National Institutes of Health diagnostic criteria.

Results Microvascular abnormalities were detected in 105 of 334 NF1 patients (31.4%), the simple vascular tortuosity was recognised in 78 of 105 cases (74.3%) and whether the corkscrew pattern and the moyamoya-like type showed a frequency of 42.8% (45 of 105 cases) and 15.2% (16 of 105 cases), respectively. We found a statistically significant correlation between the presence of retinal microvascular abnormalities and the patient age (p=0.02) and between the simple vascular tortuosity, the patient age and the presence of neurofibromas (p=0.002 and p=0.05, respectively).

Conclusions We identified microvascular alterations in 31.4% of patients and a statistically significant association with patient age. Moreover, the most frequent type of microvascular alterations, the simple vascular tortuosity, resulted positively associated with age and with the presence of neurofibromas.