To report a case of primary idiopathic frosted branch angiitis in a young boy.

This case report reviewed the follow-up observation of a patient who presented to us at Khatam-al-Anbia Eye Hospital, affiliated to Mashhad University of Medical Sciences, Mashhad, Iran. The patient was followed for one year. Laboratory examinations and magnetic resonance imaging (MRI) were done. Ophthalmoscopic findings, best corrected visual acuity (BCVA), Fluorescein Angiography (FAG), Indocyanine Green Angiography (ICGA) , Enhanced-depth Optical Coherence Tomography (EDI-OCT), and responses to treatments were evaluated.

Eye examination revealed symmetrical widespread retinal vasculitis, papillitis and severe macular edema, without any obvious retinal hemorrhages. All work up were negative. The patient was treated with 1mg/kg/day oral prednisolone and topical corticosteroid.There was significant improvement in vision,vascular sheathing and exudates.

The clinical and paraclinical findings were typical of frosted branch angiitis. It is important for ophthalmologists to rule out secondary causes of frosted branch angiitis.