BACKGROUND: Idiopathic retinal vasculitis, aneurysms, and neuroretinitis (IRVAN) 
syndrome presents with characteristic clinical manifestations such as aneurysms 
at arteriolar bifurcations and optic nerve and retinal vascular inflammation. 
Regression of such features on treatment with anti-tubercular therapy (ATT) 
combined with corticosteroids has not been reported in literature.
FINDINGS: A 30-year-old female with sudden painless decreased vision in the left 
eye was referred with a diagnosis of presumed tuberculous retinal vasculitis and 
a positive tuberculin skin test. Based on the clinical and angiographic features 
of the right eye, a diagnosis of IRVAN syndrome was made. In the left eye, the 
patient had vitreous hemorrhage for which pars plana vitrectomy was performed. 
The vitreous sample was positive for Mycobacterium tuberculosis using multiplex 
polymerase chain reaction, and the patient was started on standard four-drug ATT 
and oral corticosteroids. At 6-month follow-up, vanishing of retinal arterial 
aneurysms was observed.
CONCLUSIONS: The pathogenesis of IRVAN syndrome is uncertain. One of the 
postulates is that the features of arterial aneurysms and other retinal vascular 
alterations occur secondary to acquired inflammatory reaction. We hypothesize 
that IRVAN syndrome may be a morphological diagnosis possibly associated with 
various entities, one of which could be ocular tuberculosis. It may be prudent 
to rule out intraocular tuberculosis in cases labeled as IRVAN syndrome in an 
endemic population.