IV q12h) Valganciclovir (900 mg twice daily orally for 3 weeks induction, then 450 mg twice daily po for maintenance) Antiviral agents administered intravitreally can provide beneficial adjunctive therapy, especially if retinitis is threatening the macula [eyewiki.aao.org]

Physical examination Anterior segment involvement may include episcleritis, scleritis, corneal edema, keratic precipitates, and anterior chamber inflammation. [eyewiki.aao.org]

Laser may be difficult in view of painful red eye, severe media haze due to vitritis, posterior synechia, and cataract. Also, laser over the necrotic, swollen white retina may cause iatrogenic breaks. [eyewiki.aao.org]

An animal model of ARN suggests that involvement in the contralateral eye occurs via retrograde axonal transport to the hypothalamus and the contralateral retina. [eyewiki.aao.org]

Risk factors Genetics are believed to play a role in an individual’s risk for ARN with antigen expression of: HLA-DQw7, HLA-Bw62, and HLA-DR4 in American Caucasian populations and HLA-Aw33, HLA-B44, and HLA-DRw6 in Japanese populations. [eyewiki.aao.org]