Multimodal Imaging of Rift Valley Fever Outer Retinitis

To report a case of Rift Valley Fever retinitis studied with multimodal imaging.

A 50-years-old man from Sudan, diagnosed with Rift Valley fever, presented with complete loss of vision in the right eye and visual impairment in the left. Multimodal imaging was performed at baseline and follow-up.

Upon examination, the right eye showed complete optic nerve atrophy, diffuse dot-blot hemorrhages and patches of retinitis. The left eye had a visual acuity of 20/40 with no anterior chamber nor vitreous inflammatory cells. Fundus examination of the left eye showed diffuse patches of retinitis that on SD-OCT were confined to the outer retina, with a retinal pigment epithelium reactive thickening. These areas of active retinitis where hypofluorescent on fluorescein angiography (blockage) and the RPE hypertrophy cause hyperautofluorescence. The patient was treated empirically with oral and intravitreal steroid to stabilize the course of the retina infection. On the 3 months follow up the areas of retinitis had consolidated with RPE sub-atrophy that cause hypoautofluorescence. The left eye visual acuity was stable.

Rift Valley Fever etina lesions seem to be confined to the outer retina, and optic nerve involvement with RNFL loss seems to be the main cause of vision loss when the macula is spared.