Non-CMV Necrotizing Herpetic Retinitis
Both varicella-zoster virus (VZV) and herpes simplex virus (HSV) can cause necrotizing retinitis in patients, whether immunocompromised or not. Unlike CMV, these infections can progress rapidly and therefore should be treated aggressively. Two distinct clinical syndromes have been described: (1) acute retinal necrosis (ARN) syndrome and (2) progressive outer retinal necrosis (PORN) syndrome. Characteristic features of ARN include the presence of 1—or more typically, multiple—foci of retinitis, which usually occur in the periphery and are associated with occlusive retinal vasculitis and moderate to severe anterior chamber and vitreous inflammation (Fig 11-14).
PORN occurs in patients who are severely immunocompromised, usually as the result of AIDS, and consists of rapidly progressive, multifocal necrotizing retinitis with little or no anterior chamber or vitreous inflammation. Initial involvement of the peripheral retina is most common, with rapid progression and coalescence of lesions (Fig 11-15).
Evaluation for these infections should include serologic testing for syphilis as well as intraocular fluid aspiration for use in PCR analysis in order to identify DNA from VZV, HSV, CMV, and Toxoplasma gondii. Because ARN and PORN progress rapidly, treatment should commence immediately upon suspicion of either. Some specialists initiate therapy with intraocular injection of ganciclovir or foscarnet, particularly when the macula or optic nerve is threatened. High-dose antiviral therapy, using either intravenous acyclovir or oral valacyclovir (2 grams three times daily) for a minimum of 7 days, should be administered. Thereafter, immunocompetent patients should be treated with oral suppressive therapy; treatment duration can vary from several months to long-term, even lifelong treatment. Patients with HIV/AIDS should be treated at least until the CD4+ cell count exceeds 200/μL, or perhaps indefinitely (Table 11-3). Once antiviral therapy is initiated, systemic corticosteroids can be added in nonimmunocompromised patients and then tapered over 3–6 weeks.
Figure 11-14 Peripheral necrotizing herpetic retinitis (acute retinal necrosis). Color fundus photograph montage shows intraretinal hemorrhage and full-thickness opacification of the retina.
(Courtesy of Mark W. Johnson, MD, and Richard Hackel, CRA. Used with permission from Aizman A, Johnson MW, Elner SG. Treatment of acute retinal necrosis syndrome with oral antiviral medications. Ophthalmology. 2007;114(2):307–312.)
Figure 11-15 Progressive outer retinal necrosis (PORN) syndrome. The color fundus photograph montages show the rapid progression of retinitis from initial presentation (A), day 3 (B), and day 6 (C). An aqueous biopsy was positive for varicella-zoster polymerase chain reaction (PCR).
(Courtesy of Daniel F. Martin, MD and Stephen J. Kim, MD.)
Schoenberger SD, Kim SJ, Thorne JE, et al. Diagnosis and treatment of acute retinal necrosis: a report by the American Academy of Ophthalmology. Ophthalmology. 2017;124(3): 382–392.
Excerpted from BCSC 2020-2021 series: Section 10 - Glaucoma. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.