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Surgical repair of retinal detachment associated with viral retinitis
Published in A Peyman MD Gholam, A Meffert MD Stephen, D Conway MD FACS Mandi, Chiasson Trisha, Vitreoretinal Surgical Techniques, 2019
The PORN syndrome occurs in immunosuppressed patients with a median CD4 count of 21 cells/μl.9 Characteristic findings include multiple discrete areas of deep retinal opacification that develop in the macula in 33% of patients. There is extremely rapid progression to confluence, resulting in large areas of full-thickness necrosis. The PORN syndrome can be distinguished from CMV retinitis on the basis of multifocality, lack of hemorrhage, absence of vitreous cells, and rapid spread. Features that help distinguish PORN from ARN include early involvement of the outer retina, lack of arteritis, and absence of significant vitritis. Furthermore, ARN, even in patients with AIDS, typically presents with higher CD4 counts, as mentioned above.
Herpes Simplex Virus Infections in Immunocompromised Patients
Published in Marie Studahl, Paola Cinque, Tomas Bergström, Herpes Simplex Viruses, 2017
HSV retinitis: Retinal manifestations include the acute retinal necrosis (ARN) and the progressive outer retinal necrosis (PORN), also named rapidly progressive herpetic retinal necrosis (RPHRN). These entities are usually considered as two distinct syndromes, although they might represent different expressions of a spectrum of HSV manifestations. Both ARN and PORN can be caused by either HSV-1 or -2 or VZV, the latter being however much more frequent. HSV and VZV manifestations are clinically undistinguishable and PCR of aqueous or vitreous fluid is used to define their etiology (100).
Changes Associated with CNS Infections Caused by the Herpesvirus Varicella Zoster Virus (VZV) and Models of VZV Neurotropism
Published in Sunit K. Singh, Daniel Růžek, Neuroviral Infections, 2013
Zoster on the head, reflecting VZV reactivation from the third and fifth cranial nerves or the trigeminal nerve, frequently involves the anterior and posterior chambers of the eye (see reviews by Ghaznawi et al. 2011; Gupta et al. 2011; Kaufman 2008). A classical indicator of potential ocular involvement is “Hutchinson sign” in which a zoster lesion is on the nose or its tip. Virtually every ocular component can become affected by VZV: the cornea may develop a stromal keratitis, reflecting a virus-triggered immune-mediated disease similar to that seen for reactivating HSV-1. Zoster may cause optic neuritis (inflammation of the optic nerve) and ophthalmoplegia (paralysis of the eye muscles). Infection of the retinal tissues and subsequent inflammatory responses may trigger progressive outer retinal necrosis (PORN) and acute retinal necrosis (ARN) that can rapidly lead to blindness. Both PORN and ARN are more frequent in AIDS patients and need a differential diagnosis from HSV. VZV may also cause facial nerve palsies around the ocular globe, ocular pain, uveitis, and iridocyclitis, as well as disciform keratitis. A further problematic neurological issue is that up to 8% of herpes zoster ophthalmicus patients are associated with a neurotrophic cornea, in which there is partial to almost complete loss of sensory and nociceptive abilities. This leads to undetected iatrogenic damage, wounding, scarring, and increased risk of bacterial infection, particularly in elderly patients, which may impair or block the visual axis.
HIV-induced Retinitis
Published in Ocular Immunology and Inflammation, 2020
Juliana Wons, John Kempen, Justus G. Garweg
Upon the diagnosis of ARN or an atypical necrotizing retinopathy such as PORN, usual immediately treatment is with intravenous or oral antivirals such as acyclovir, valacyclovir, or foscarnet.5,68 The induction treatment for PORN may include a combination of both in order to improve the generally poor prognosis. If the disease is more aggressive a combination therapy with additional intravitreal ganciclovir or foscarnet appears to have greater therapeutic efficacy.5 However, intravitreal therapy should never be used without systemic treatment because of the risk to the fellow eye.5 If vitritis is significant, short-term oral corticosteroids may be added. Overall, there is little information in the ophthalmologic or infectious disease literature to guide management of PORN in the cART era. Whereas cART has led to more patients surviving beyond their initial diagnosis of AIDS and consequently suffering more frequently from associated opportunistic infections.68
Challenges in Treating Intraocular Inflammation in HIV Patients
Published in Ocular Immunology and Inflammation, 2020
Ilaria Testi, Safia Ahmed, Camrun Shah, Rupesh Agrawal
Ocular opportunistic infections can manifest with a recognized severe disease phenotype, which only occurs in immunocompromised subjects. Progressive outer retinal necrosis (PORN), first described by Forster in 1990 and caused by varicella zoster virus, affects profoundly immunocompromised individuals, such as HIV subjects with CD4 + T-lymphocytes count <200 cells/µL.5 Once diagnosed, PORN was associated with a bad visual prognosis with 2/3 of the eyes involved progressing to no light perception within 4 weeks of its onset.6,7,8,9 Retinal detachment occurs in nearly 70% of patients with PORN, and despite the anatomical success achieved surgically with pars plana vitrectomy and silicone oil tamponade, visual acuity remains often poor, mostly depending on extensive retinal necrosis and optic atrophy.18,19
Management of Intraocular Infections in HIV
Published in Ocular Immunology and Inflammation, 2020
Ilaria Testi, Sarakshi Mahajan, Rupesh Agrawal, Aniruddha Agarwal, Alessandro Marchese, Andre Curi, Moncef Khairallah, Yee Sin Leo, Quan Dong Nguyen, Vishali Gupta
Varicella-Zoster Virus (VZV), Herpes Simplex Virus (HSV), and Cytomegalovirus (CMV) belong to the family of Herpes viruses. Host immunity determines the clinical picture following reactivation from latency, which is usually characterized by acute retinal necrosis (ARN) in immunocompetent individuals and progressive outer retinal necrosis (PORN) or CMV retinitis in immunocompromised patients.69 Although initially thought to be associated with immune competence, authors have shown clinical features consistent with ARN even in HIV patients.707172–73 Diagnosis of ARN revolved around diagnostic criteria outlined by American Uveitis Society in 1994, which included one or more foci of retinal necrosis in the peripheral retina, rapid progression in the absence of treatment, occlusive vasculopathy, circumferential spread, and inflammatory reaction in vitreous and anterior chamber. PORN clinically presents as minimal ocular infection, involvement of outer retinal with inner retinal, and vasculature sparing, but rapid progressive course and poor response to intravenous therapy.74–76