Retinal Vascular Abnormalities in a Large Cohort of Patients Affected by Neurofibromatosis Type-1: a Study Using OCT-angiography

Abstract

Purpose : To evaluate the prevalence, the vascular features and the clinical diagnostic implication of Retinal Vascular Abnormalities (RVAs) associated with neurofibromatosis type-1 (NF1) in a large cohort of patients.

Methods : Three-hundred patients affected by NF1 were consecutively enrolled. The presence of RVAs was detected by means of infrared (IR) confocal scanning laser ophthalmoscopy images. Two masked ophthalmologists evaluated each image. Three hundred age and race matched healthy subjects were enrolled as a healthy control group. Fluorescein (FA), indocyanine green (ICGA) and OCT-angiography (OCT-A) were also performed in patients with RVAs.

Results : RVAs were detected in 18 patients with NF1 (6.0%) and none of the healthy subjects showed it. RVAs appeared in all cases as well defined, small, tortuous retinal vessels with a spiral aspect, originating from small tributaries of retinal veins. RVAs were unilateral in 17 cases (94%) and single in 15 (83.3%) cases, located at the posterior pole in 6 (33.3%) cases or along the temporal vascular arcades in 12 (66.6%) cases. The inter-operator agreement in the detection of RVAs was 1.0 (complete agreement). Presence of RVAs did not correlate with the presence of other specific ocular or systemic NF1 features (p>0.05). Eyes affected by RVAs showed a normal visual acuity. On OCT-A, RVAs appeared as an isolated tortuous vessel of the superficial vascular plexus in all cases, associated with localized anomalous crowded and congested capillary network of the deep vascular plexus in 75% of cases.

Conclusions : RVAs are present in a limited proportion of patients affected by NF1 and can be considered a new specific clinical entity and an additional distinctive sign of NF1.

This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.