| Acute retinal necrosis syndrome (ARNS) is a clinically defined syndrome characterized by confluent peripheral necrotising retinitis, occlusive vasculitis and vitritis in otherwise healthy patient. Urayama first described it in 1971. Willerson recognized the bilaterality of this disease, and the term bilateral acute retinal necrosis was coined in 1978. In 1994, the Executive Committee of the American Uveitis Society published a consensus disease definition for ARNS. Eyes with ARNS must demonstrate one or more foci of retinal necrosis with discrete borders, located in the peripheral retina. The diseases must progress rapidly in the absence of therapy and spread circumferentially. Evidence of occlusive vasculopathy and arteriolar involvement must be seen, as well as a prominent inflammatory reaction in the vitreous and anterior chamber. Patients will frequently show optic neuropathy, and many will have scleritis with associated pain. Almost 70 percent or more of cases are complicated with retinal detachment.Multiple viruses have been shown to cause ARNS. Pathologic specimens, intraocular antibody production, and polymerse chain reaction analysis have identified varicella zoster virus (VZV), herpes simplex virus type 1(HSV-1), and type 2(HSV-2), and, rarely, cytomegalovirus(CMV) as potentially causative agents.Severe retinal ischemia and vitreous organization that accompanies widespread zones of necrotizing retinitis have been shown to have significant effect on the high incidence of retinal detachment in these cases. Retinal detachment secondary to ARNS has a complex nature and usually results in severe visual loss. Anatomic success of surgical repair with scleral buckling was achieved in only 22 percent of the eyes. Nevertheless, with the refinement of vitreoretinal surgical techniques, there was an increased rate of retinal reattachment. It was 80 percent or more.In this report, we reviewed retrospectively 15 patients (17 eyes) with ARNS who managed in our department in the past several years, presented the clinical features and described the anatomic and functional results.Of the 17 eyes, 16(94.1%) showed partial improvement in visual acuity after drugs and laser therapy. Prophylactic barrier laser photocoagulation was carried out in 4 eyes but retinal detachment occurred after 1-4 months despite previous laser therapy in 2 eyes. Retinal detachment was diagnosed in 12 eyes(70.5%). Tow patients gave up next therapy and lost their vision in the end. Three-port pars plana vitrectomy was carried out in 10 eyes. Barrier endolaser photocoagulation was applied around the retinal breaks. Silicone oil or C3F8 gas were used. Nevertheless, due to the progression of the PVR process and occurrence of reproliferation, redetachment of retina occurred in 2 eyes and multiple surgical procedures might be required, but they gave up and lost their vision in the end. Silicone oil removal was carried out and was followed by reinjection in 1 eyes. The patient enderwent silicone-oil removal associated with peeling of the epiretinal membrane. This resulted in the retina remaining stable but the visual acuity deteriorating obviously. Recurrent episodes of anterior uveitis occurred during the follow-up in 3 eyes after surgery and were treated with topical steroids. The majority of ARNS eyes obtained better visual improvement after integrated treatment of drugs, laser and surgery, but only 40.7% of eyes with ARNS maintained ambulatory vision (0.1 or better). 4 patients lost their visions completely after giving up next treatment.We can learn from above results that despite the high anatomic success rate, the functional results remain unfavorable due to extensive retinal damage secondary to infection and ischemia, and the presence of severe optic neuropathy. So it is very important for early diagnosis and treatment according to etiology and pathogenesis, which can assist to improve final visual acutity. |
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