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The idiopathic retinal vasculitis, aneurysm, and neuroretinitis (IRVAN) syndrome is a rare clinical entity characterised by peripheral retinal vascular occlusion, retinal vasculitis, and multiple posterior retinal arterial aneurysms.1,2 In most reported cases, visual acuity was aggravated.2–4 We report a case of successfully treated IRVAN syndrome in which good long term visual acuity has been maintained.
A 36 year old woman visited the Kansai Medical University Hospital on January 1999, complaining of flies flying in her right eye for the past year. She also had visual disturbance and metamorphopsia for 2 months in her right eye. Her best corrected visual acuity was 20/40 in the right eye and 20/16 in the left eye. Inflammatory cells were noted in both the anterior chamber and vitreous cavity. There was mild rubeosis iridis in the left eye. In the right eye, there was a fibrovascular membrane in the epipapillary area accompanying tractional retinal detachment, thick hard exudates on nasal side of the fovea, and vitreous haemorrhage (Fig 1A). Her optic disc was mildly hyperaemic, and multiple aneurysms surrounded by perivascular exudation were observed at the posterior retinal artery in the left eye (Fig 1B). Extensive arterial and venous vascular occlusion and adjacent anomalous arteriovenous anastomosis were observed at the peripheral retina in both eyes (Fig 2).
Systemic examination and laboratory findings did not suggest systemic abnormality, and the family history was not contributory. Oral prednisolone was initiated at 50 mg/day and decreased gradually. In an attempt to prevent peripheral retinal neovascularisation, panretinal photocoagulation (PRP) was carried out to treat the peripheral retinal non-perfusion area. Since vitreous haemorrhage in the right eye did not improve, right eye vitrectomy was performed on March 1999, and tractional retinal detachment and vitreous haemorrhage subsequently improved. The aneurysms disappeared by 5 months and the hard exudates by 12 months. Her corrected visual acuity improved to 20/20 in the right eye and 20/16 in the left eye by February 2003 (Fig 1C and D).
The disappearance of retinal aneurysm in IRVAN has been reported in two cases.3,4 In both of these cases, scattered retinal photocoagulation was performed on the peripheral retinal non-perfusion area.3,4 In one case in which scattered retinal photocoagulation was not performed, it has been reported that some aneurysms enlarged, others became small, and new aneurysms appeared.5 In our case, all retinal arterial aneurysms vanished after PRP (Fig 1B and D). These results strongly suggest that PRP applied to the retinal non-perfusion area is useful and should be performed during the early phase. On the other hand, it has been reported that retinal lesions are unresponsive to oral steroids in most cases of IRVAN.2,4,5 In our case, systemic oral steroid was given to treat the retinal vasculitis. The effect of oral steroid in IRVAN will need further examination. The results in our case and past cases strongly suggest that PRP applied to the non-perfusion area is the most important treatment for IRVAN. We think vitrectomy must precede PRP, because PRP cannot be performed when there is vitreous haemorrhage and retinal detachment.