Acute Retinal Necrosis
Acute Retinal Necrosis is an eye condition that occurs mainly in young, healthy, immunocompetent individual. It is caused by herpes simplex virus or varicella-herpes zoster virus (VZV) viral reactivation in the retina.
In young people it is caused mainly by Herpes Simplex Virus while in older patients it is caused mainly by varicella-herpes zoster virus. It can be a bilateral disease in which the second eye can be involved within 6 weeks.
Some patients complain of acute visual loss, within few days with red eye and ocular pain while other has gradual disease with mild decrease in visual acuity.
There are areas of ischemia and necrosis in the periphery of the retina due to occlusive retinal vasculitis that is associated with exudates, hemorrhages, vitritis and sometimes with anterior uveitis.
Diagnosis of Acute Retinal Necrosis
Diagnosis of this condition is usually done through clinical suspicion of the symptoms.
Laboratory tests such as Polymerase chain reaction (PCR) of vitreous and aqueous sample can be very helpful to identify viral antigen can also be used.
Fluorescein angiography can be helpful in identifying areas on ischemia and necrosis and also in follow up visits.
Treatment of Acute Retinal Necrosis
Treatment of Retinal Necrosis involves laser photocoagulation to areas of peripheral retinal necrosis which should be started early to prevent spreading of the disease towards the macular area and also to prevent retinal detachment.
Although Antiviral therapy as systemic medication such as acyclovir, valacyclovir ,valganciclovir and famciclovir. Usually we start through intravenous therapy for 2 weeks then we switch to oral medication.
Intravitreal foscarnet, valacyclovir, and famciclovir can also be used.
Corticosteroid, either systemic or Intravitreal injection can be used to decrease uveitis, optic nerve involvement and retinal vasculitis. It should be used with antiviral medications.