Risk factors and prognostic factors associated with retinal detachment and visual outcomes in acute retinal necrosis.

OBJECTIVE: To investigate the risk factors and prognostic factors that affect the long-term clinical outcomes of acute retinal necrosis (ARN). METHODS: A retrospective study of patients with ARN who underwent treatment and completed follow-up in our ophthalmology department from 2011 to 2021 was conducted. The incidence and risk factors of retinal detachment (RD) and prognostic factors affecting long-term clinical outcomes, such as late-onset RD and final vision loss (< 20/200), were analyzed. RESULTS: Totally 59 ARN patients (65 eyes) with an average follow-up of 48.9 months were enrolled. During the follow-up period, RD occurred in 34 eyes (52.3%). The risk factors for RD included quadrants of involved retinal necrosis (odds ratio [OR], 4.181; 95% confidence interval [CI], 1.950-10.834) and initial intraocular viral load (OR, 1.721; 95% CI, 1.071-3.083). Early intravitreal antiviral treatment (OR, 1.204; 95% CI, 1.040-1.480) was independently associated with a decreased risk of late-onset RD. The factors independently associated with an increased risk of final vision loss were worse initial visual acuity (OR, 3.895; 95% CI, 1.551-13.662) and late-onset RD (OR, 8.043; 95% CI, 1.380-67.216). In addition, we utilized the fluctuating magnitude of viral load to quantify the extent of its reduction in comparison to its original value following the initial intravitreal antiviral injection (IAI). This ratio was strongly related to initial intraocular IL-8 concentration (Spearman correlation coefficient=-0.741, P = 0.000) and moderately related to the initial degree of aqueous flare (Spearman correlation coefficient=-0.508, P = 0.010). CONCLUSION: RD is a common and severe complication of ARN with multiple risk factors, such as initial retinitis involvement area and initial intraocular viral load. Active local antiviral therapy may reduce the risk of late-onset RD. The antiviral medication should be adjusted according to the inflammatory state. Therefore, timely detection of causative viruses and intensive systemic and local antiviral therapy is crucial for preserving visual function in ARN patients.

Acute Retinal Necrosis Caused by Varicella Zoster Virus and Cytomegalovirus Co-Infection.

PURPOSE: To report the clinical course of two cases of acute retinal necrosis (ARN) caused by varicella zoster virus (VZV) and cytomegalovirus (CMV) co-infection detected by polymerase chain reaction (PCR) on aqueous tap. METHODS: Observational case reports. RESULTS: Two patients presented to our services with unilateral panuveitis suggestive of ARN complicated by hemorrhagic vasculitis and started empirical therapy. Aqueous PCR was performed on the same day and showed double positivity for VZV and CMV, which guided treatment. At follow-up, wide-field color fundus imaging and high-resolution optical coherence tomography showed resolution of active retinitis. CONCLUSION: Our cases suggest that ARN complicated by hemorrhagic vasculitis may be secondary to CMV and VZV co-infection, both in patients with an unremarkable clinical history and in those with immunodeficiency. In our cases, aqueous PCR testing was of paramount importance to determine the aetiology of ARN and to adjust the antiviral therapy accordingly.

Use of intravitreal antiviral injection during vitrectomy in the treatment of acute retinal necrosis: anatomic and visual outcomes.

PURPOSE: To investigate whether intravitreal antiviral injection (IAI) during vitrectomy reduces the postsurgical retinal detachment (RD) rate and improves the visual prognosis of patients with acute retinal necrosis (ARN). METHODS: This retrospective cohort study included ARN patients treated at a tertiary hospital between January 2013 and December 2020. Patients who underwent pars plana vitrectomy (PPV) alone or combined with intraoperative IAI were classified in PPV-only group and PPV + IAI group, respectively. The incidence of postsurgical RD and the best corrected visual acuity (BCVA) between the groups was compared. A multivariate Cox hazard analysis was employed to explore the risk factors of postsurgical RD. A multivariate logistic regression analysis was applied to assess the impact of intraoperative IAI on preventing severe vision loss (SVL). RESULTS: Fifty-seven eyes with ARN with a median follow-up of 18.5 months were included in the study. There was no significant association between intraoperative IAI during vitrectomy and a reduced risk of postsurgical RD (hazard ratio [HR], 2.65; 95% CI, 0.71-9.89) or SVL at the 6-month follow-up visit (odds ratio [OR], 0.92; 95% confidence interval [CI], 0.25-3.35). Better baseline best-corrected visual acuity (BCVA) was identified to associate with a higher risk of postsurgical RD (HR, 0.33; 95% CI, 0.14-0.81) and a lower risk of SVL at 6 months (OR, 2.28; 95% CI, 1.10-4.89). CONCLUSION: We did not observe a significant effect of intraoperative IAI on the anatomic and visual outcomes of ARN patients in this study. Intraoperative IAI may not be a necessary treatment option for ARN patients who receive vitrectomy.

Reactivation of herpes simplex virus 2 presenting as recurrent acute retinal necrosis following COVID-19 vaccination.

PURPOSE: Acute retinal necrosis (ARN) is a vision-threatening uveitis caused by herpesviruses reactivation, which has recently been suggested to be associated with COVID-19 infection and after vaccination against it. CASE DESCRIPTION: We present the case of a 58-year-old Japanese woman with ARN in the left eye due to herpes simplex virus 2 (HSV2) two days after receiving the fifth dose of the BNT162b2 mRNA COVID-19 vaccine. The patient demonstrated an ARN history in the right eye and had been treated for it. The patient was administered oral steroids and immunosuppressive drugs for mixed connective tissue disease and organizing pneumonia. The patient was treated with intravenous acyclovir and foscarnet, and a vitrectomy was performed for retinal detachment. The lesion took approximately two months to scar. CONCLUSION: This report suggests that patients with an ARN history might be at risk of ARN recurrence because of the reactivation of the herpes simplex virus induced by COVID-19 vaccination.

Automated early detection of acute retinal necrosis from ultra-widefield color fundus photography using deep learning.

BACKGROUND: Acute retinal necrosis (ARN) is a relatively rare but highly damaging and potentially sight-threatening type of uveitis caused by infection with the human herpesvirus. Without timely diagnosis and appropriate treatment, ARN can lead to severe vision loss. We aimed to develop a deep learning framework to distinguish ARN from other types of intermediate, posterior, and panuveitis using ultra-widefield color fundus photography (UWFCFP). METHODS: We conducted a two-center retrospective discovery and validation study to develop and validate a deep learning model called DeepDrARN for automatic uveitis detection and differentiation of ARN from other uveitis types using 11,508 UWFCFPs from 1,112 participants. Model performance was evaluated with the area under the receiver operating characteristic curve (AUROC), the area under the precision and recall curves (AUPR), sensitivity and specificity, and compared with seven ophthalmologists. RESULTS: DeepDrARN for uveitis screening achieved an AUROC of 0.996 (95% CI: 0.994-0.999) in the internal validation cohort and demonstrated good generalizability with an AUROC of 0.973 (95% CI: 0.956-0.990) in the external validation cohort. DeepDrARN also demonstrated excellent predictive ability in distinguishing ARN from other types of uveitis with AUROCs of 0.960 (95% CI: 0.943-0.977) and 0.971 (95% CI: 0.956-0.986) in the internal and external validation cohorts. DeepDrARN was also tested in the differentiation of ARN, non-ARN uveitis (NAU) and normal subjects, with sensitivities of 88.9% and 78.7% and specificities of 93.8% and 89.1% in the internal and external validation cohorts, respectively. The performance of DeepDrARN is comparable to that of ophthalmologists and even exceeds the average accuracy of seven ophthalmologists, showing an improvement of 6.57% in uveitis screening and 11.14% in ARN identification. CONCLUSIONS: Our study demonstrates the feasibility of deep learning algorithms in enabling early detection, reducing treatment delays, and improving outcomes for ARN patients.

A Single-Center Case Series of Acute Retinal Necrosis at Teikyo University: Clinical Characteristics and Treatment Outcomes.

Aim To evaluate the clinical characteristics, treatment course, and prognosis of patients with acute retinal necrosis (ARN), which can rapidly progress and cause severe vision loss. Design Single-center retrospective case series. Subjects and methods Six patients and seven eyes diagnosed with ARN at Teikyo University Hospital were included in this study. The clinical presentation and treatment prognosis were investigated based on data obtained from medical records. Results The mean age of the patients at the initial diagnosis was 63.6 years. Although the mean Logarithm of the Minimum Angle of Resolution (LogMAR) visual acuity tended to decrease from 0.77 at the first visit to 1.29 at the last visit, the difference was not statistically significant. Intraocular manifestations observed during the study period included ocular hypertension (14.3%), anterior uveitis (100.0%), retinal hemorrhage (71.4%), vitreous opacity (100.0%), retinal exudative vasculitis (85.7%), optic nerve atrophy (85.7%), retinal vascular occlusion (85.7%), choroidal atrophy (85.7%), macular edema (100.0%), subretinal fluid in the macula (71.4%), and retinal detachment (85.7%). Treatment modalities included oral and intravitreal antivirals (85.7%), antiplatelet medications (85.7%), steroid eye drops (85.7%), subcapsular (57.1%) and vitreous (42.9%) steroid injections, oral steroids (71.4%), and surgical intervention (85.7%). Vitrectomy led to retinal recovery in all five eyes that underwent the procedure. Conclusions The visual prognosis of patients with ARN is poor, particularly in those with preexisting visual impairment. Early detection coupled with antiviral therapy and prompt surgical intervention have been identified as potential factors that influence visual outcomes. Given the severity of ARN, collecting data from multiple centers could aid in devising future diagnostic and therapeutic strategies.

Common Practice Patterns in the Diagnosis and Management of Acute Retinal Necrosis: A Survey Study of Uveitis Specialists.

PURPOSE: Due to lack of large randomized clinical trials to determine best practices in treating acute retinal necrosis (ARN), there is not a clear consensus amongst ophthalmologists on how to best manage this potentially blinding condition. The aim of this study is to survey common practice patterns and analyze the factors that affect ophthalmologists' management of ARN. METHODS: An anonymous survey was distributed to uveitis and retina specialists who are members of the American Uveitis Society (AUS) via email to query practice patterns regarding ARN. The survey included 22 questions with an additional 10 questions based on response. Survey question topics included demographic information, diagnostic testing, antiviral therapy, corticosteroids, and surgical procedures. RESULTS: 67 surveys were included for analysis. Most respondents (87%) always or frequently obtain intraocular aqueous fluid for diagnostic PCR testing. The majority of respondents would administer intravitreal antiviral injections to a unilateral immunocompetent ARN patient (67%), but would be even more likely to do so for a bilateral immunosuppressed ARN patient (87%). Respondents tend to treat ARN with systemic rather than local corticosteroids, with the majority (63%) of respondents initiating corticosteroid treatment 48 hours after treatment. Most respondents (79%) never perform a vitrectomy to manage ARN unless the patient has a retinal detachment or tear. The majority (63%) rarely or never perform prophylactic laser barricade, but may consider laser treatment if there is extensive retinal involvement. CONCLUSION: Current practice patterns for diagnosis and management of ARN among AUS members generally align with the suggested practices outlined by the American Academy of Ophthalmology.

Examining the etiological factors resulting in retinal detachment following prophylactic vitrectomy in the context of acute retinal necrosis syndrome.

OBJECTIVE: The aim of this study is to elucidate the factors contributing to the occurrence of retinal detachment (RD) following prophylactic vitrectomy in cases of acute retinal necrosis (ARN) syndrome. METHODS: A retrospective examination was undertaken, encompassing the medical records of patients diagnosed with ARN who underwent prophylactic vitreous intervention at the Ophthalmology Department of Wuhan University Renmin Hospital East Campus between October 2019 and September 2023. Subsequently, patients who manifested RD in the postoperative period were identified, and a comprehensive analysis was conducted to ascertain the factors underlying the occurrence of RD post-surgery. RESULTS: This study comprised 14 cases (involving 14 eyes) of patients diagnosed with ARN who underwent prophylactic vitreous intervention. The findings revealed that 4 patients experienced postoperative RD, resulting in an incidence rate of 28.57%. Notably, among these cases, 3 cases of RD manifested in the presence of silicone oil, while 1 case occurred subsequent to the removal of silicone oil. All 4 cases of RD exhibited varied degrees of proliferative vitreoretinopathy. Following the occurrence of RD, all patients underwent a secondary vitreous intervention coupled with silicone oil tamponade, leading to successful reattachment of the retina. However, despite these interventions, there was no significant enhancement observed in postoperative visual outcomes when compared to preoperative levels. CONCLUSION: RD following prophylactic vitrectomy in cases of ARN is not an infrequent occurrence and is primarily linked to the postoperative onset of proliferative vitreoretinopathy.

Varicella zoster virus-induced autophagy in human neuronal and hematopoietic cells exerts antiviral activity.

Autophagy is a degradational pathway with pivotal roles in cellular homeostasis and survival, including protection of neurons in the central nervous system (CNS). The significance of autophagy as antiviral defense mechanism is recognized and some viruses hijack and modulate this process to their advantage in certain cell types. Here, we present data demonstrating that the human neurotropic herpesvirus varicella zoster virus (VZV) induces autophagy in human SH-SY5Y neuronal cells, in which the pathway exerts antiviral activity. Productively VZV-infected SH-SY5Y cells showed increased LC3-I-LC3-II conversion as well as co-localization of the viral glycoprotein E and the autophagy receptor p62. The activation of autophagy was dependent on a functional viral genome. Interestingly, inducers of autophagy reduced viral transcription, whereas inhibition of autophagy increased viral transcript expression. Finally, the genotype of patients with severe ocular and brain VZV infection were analyzed to identify potential autophagy-associated inborn errors of immunity. Two patients expressing genetic variants in the autophagy genes ULK1 and MAP1LC3B2, respectively, were identified. Notably, cells of both patients showed reduced autophagy, alongside enhanced viral replication and death of VZV-infected cells. In conclusion, these results demonstrate a neuro-protective role for autophagy in the context of VZV infection and suggest that failure to mount an autophagy response is a potential predisposing factor for development of severe VZV disease.

Acute retinal necrosis.

Acute retinal necrosis (ARN) is a rare, progressive viral uveitis, with the majority of cases caused by herpesviruses. The diagnosis of ARN is often delayed, and most patients will have some degree of permanent visual loss. We report a case of ARN in a previously healthy 32-year-old patient.

Atypical Peripheral Retinal Necrosis Without Ocular Inflammation and Retinal Whitening in a Patient With Acute Myelogenous Leukemia: A Case Report.

Retinal necrosis is a severe condition that threatens visual function. It is caused by viruses that are known to cause acute retinal necrosis (ARN) and progressive outer retinal necrosis (PORN), which are called necrotizing herpetic retinopathies (NHR). ARN causes severe intraocular inflammation, including anterior chamber intravitreal cells, keratic precipitate, vitreous opacity, and retinal vasculitis, whereas intraocular inflammation in PORN is considered mild or virtually absent. In addition, PORN is a disease that manifests in immunosuppressive patients, such as those with acquired immunodeficiency syndrome. Here, we present a case of unilateral retinal necrosis after chemotherapy, allogeneic peripheral blood stem cell transplantation, and cord blood transplantation for acute myelogenous leukemia (AML) in a 31-year-old male patient. AML treatment resulted in metabolic remission, and oral steroids and tacrolimus were continued. After two days, the patient visited an ophthalmologist because he noticed a sudden onset of floaters and visual field disturbance in the left eye. The peripheral retina was already necrotic in all layers, causing total retinal detachment. Intraocular inflammation, retinal opacity, or hemorrhagic spots in the fundus were not observed. His previous CD4 count was 43 cells/µL. A polymerase chain reaction test of the anterior chamber fluid revealed varicella-zoster virus (VZV), and vitrectomy was performed four days after disease onset. The excised vitreous demonstrated minimal opacity. The peripheral necrotic retina was excised, photocoagulation was performed on the residual retinal limbus, and silicone oil was injected to maintain retinal attachment. The retinal restoration was maintained under silicone oil tamponade, and corrected visual acuity improved to 20/32 without strong inflammation after vitrectomy. However, two months postoperatively, he contracted coronavirus disease 2019 (COVID-19), his general condition rapidly deteriorated, and he died. This case of retinal necrosis without inflammatory results in an immunocompromised patient and VZV detection in an intraocular sample led us to suspect PORN. However, the patchy or spread retinal whitening characteristic of PORN was completely absent, whereas the well-defined, peripheral, full-layer retinal necrosis characteristic of ARN was present. Thus, this is a rare case of VZV-induced NHR with partial features of PORN and ARN that progressed very silently.

Cytomegalovirus-Associated Non-Necrotizing Retinopathy, Occlusive Retinal Vasculitis, and Neovascularization.

PURPOSE: To report a rare case of cytomegalovirus (CMV)-associated non-necrotizing viral retinopathy, occlusive retinal vasculitis, papillitis, and retinal neovascularization in a young 41-year-old woman. METHODS: Case report. RESULTS: The patient presented with features of papillitis, peripapillary cotton-wool spots, pre-retinal hemorrhages, and occlusive vasculitis. Her visual acuity was 20/100 in the left eye. She developed a worsening of the disease upon initiation of systemic corticosteroids. Her serum immunoglobulins (Ig) (both IgG and IgM) were highly positive for CMV. Anterior chamber paracentesis was positive for CMV DNA using real-time polymerase chain reaction. After stopping systemic corticosteroids, she was initiated on oral valganciclovir, with rapid resolution of the vasculitis and cotton-wool spots. After three months, the patient developed retinal neovascularization and underwent pan-retinal photocoagulation. However, her uveitis was inactive, and her visual acuity improved to 20/25. CONCLUSIONS: Non-necrotizing viral retinopathy has been associated with either varicella zoster virus (VZV) or herpes simplex virus (HSV). Our case highlights that CMV can also lead to non-necrotizing retinopathy and must be suspected in patients who may be negative for VZV and HSV. Appropriate anti-viral treatment can prevent severe vision loss in these patients.

Pachychoroid Associated With Acute Retinal Necrosis Secondary to Varicella Zoster Virus.

Purpose: To report a case of pachychoroid associated with acute retinal necrosis secondary to the varicella zoster virus (VZV). Methods: A retrospective review of a single case was performed. Results: The VZV-related acute retinal necrosis with pachychoroid resolved with quiescence of the acute infectious process. Conclusions: Acute retinal necrosis can result in choroidal thickening adjacent to retinitis. Previous reports have described choroidal sparing in these cases.

Unilateral Acute Retinal Necrosis with Contralateral Non-necrotizing Herpetic Uveitis.

PURPOSE: The objective of this study is to report a case of unilateral acute retinal necrosis (ARN) with contralateral eye presenting as non-necrotizing herpetic uveitis. CASE REPORTS: Case 1: A 48-year-old female presented at our clinic with blurred vision in the right eye for 7 days. She was diagnosed with ARN in the left eye 2 weeks ago. Ophthalmic examination revealed reduced visual acuity in the right eye (20/33) with the presence of optic disc swelling and macular exudation without peripheral necrotic lesions. With systemic antiviral therapy, optic disc swelling of the right eye vanished gradually, and the visual acuity improved to 20/20. Loss of retinal nerve fiber layer (RNFL) and decreased retinal thickness in the corresponding area occurred during follow-up. CONCLUSION: Non-necrotizing herpetic uveitis may occur in the contralateral eye of unilateral ARN under rare conditions. Structure abnormities, including loss of RNFL and focal decreased retinal thickness, are irretrievable.

Acute retinal necrosis in a patient with cervical malignant tumor treated with sintilimab: a case report and literature review.

Acute retinal necrosis (ARN) is an inflammatory disease that is primarily caused by herpesvirus infection, most commonly varicella-zoster virus (VZV), followed by herpes simplex virus (HSV) and occasionally cytomegalovirus (CMV). Sintilimab is an immune checkpoint inhibitor (ICI) that can enhance the body's anti-tumor immune response. However, treatment with ICIs may lead to reactivation of the VZV. Here, we present a case of ARN caused by VZV infection in a patient receiving sintilimab for cervical cancer. A 64-year-old female patient developed vision loss and floaters with left eye redness for one week after 22 cycles of sintilimab for cervical cancer. Based on clinical manifestations, ophthalmological examination, and vitreous humor biopsy, the patient was diagnosed with acute retinal necrosis syndrome secondary to VZV. After receiving systemic antiviral and anti-inflammatory therapy, retinal necrosis lesions and visual function improved. In conclusion, clinicians should be aware of the risk of ARN when using sintilimab and should actively monitor patients for prompt diagnosis and optimal management of this rare adverse drug reaction.

Antiviral treatment for acute retinal necrosis: A systematic review and meta-analysis.

Acute retinal necrosis is a progressive intraocular inflammatory syndrome characterized by diffuse necrotizing retinitis that can lead to a poor visual outcome, mainly from retinal detachment. The antiviral treatment approach for acute retinal necrosis varies as there are no established guidelines. We summarize the outcomes of acute retinal necrosis with available antiviral treatments. Electronic searches were conducted in PubMed/MEDLINE, EMBASE, Scopus, and Google Scholar for interventional and observational studies. Meta-analysis was performed to evaluate the pooled proportion of the predefined selected outcomes. This study was registered in PROSPERO (CRD42022320987). Thirty-four studies with a total of 963 participants and 1,090 eyes were included in the final analysis. The estimated varicella-zoster virus and herpes simplex virus polymerase chain reaction-positive cases were 63% (95% CI: 55-71%) and 35% (95% CI: 28-42%), respectively. The 3 main antiviral treatment approaches identified were oral antivirals alone, intravenous antivirals alone, and a combination of systemic (oral or intravenous) and intravitreal antivirals. The overall pooled estimated proportions of visual acuity improvement, recurrence, and retinal detachment were 37% (95% CI: 27-47%), 14% (95% CI: 8-21%), and 43% (95% CI: 38-50%), respectively. Patients treated with systemic and intravitreal antivirals showed a trend towards better visual outcomes than those treated with systemic antivirals (oral or intravenous) alone, even though this analysis was not statistically significant (test for subgroup differences P = 0.83).

False negative result of polymerase chain reaction in very early stages of acute retinal necrosis.

BACKGROUND: Viral nucleic acid testing of intraocular fluid using polymerase chain reaction (PCR) is a major laboratory examination in the diagnosis of acute retinal necrosis (ARN). Importantly, false negative PCR results may occur in several special situations. We reported a case of ARN with a negative PCR result in the aqueous humour in the very early stages of disease. CASE PRESENTATION: A female patient presented to the ophthalmologist with complaints of blurred vision and redness in her left eye. Her medical history included ARN in her right eye 10 years prior. Although the result of the aqueous viral analysis by PCR in her left eye was negative the first time (one day after the appearance of ocular symptoms), ARN in her left eye was presumed based on the clinical signs. With timely antiviral and anti-inflammatory treatments, the retinal lesions diminished. The viral load of herpes simplex virus (HSV) turned positive (7.25 × 103 copies/mL) one week later, increased to 2.49 × 105 copies/mL after three weeks, and finally turned negative about five weeks after the onset of disease. The initial HSV-IgG level in the aqueous humour was 0.01 U/mL and increased to 222.64 U/mL in the final sampling. CONCLUSIONS: The results of PCR analysis can be negative in the very early stages of ARN. Diagnosis of ARN should be made based on the clinical features, and antiviral treatments should not be delayed. Repeated PCR analysis of the aqueous humour is necessary to confirm the diagnosis and monitor the disease process.

Whole exome sequencing of patients with varicella-zoster virus and herpes simplex virus induced acute retinal necrosis reveals rare disease-associated genetic variants.

Purpose: Herpes simplex virus (HSV) and varicella-zoster virus (VZV) are neurotropic human alphaherpesviruses endemic worldwide. Upon primary infection, both viruses establish lifelong latency in neurons and reactivate intermittently to cause a variety of mild to severe diseases. Acute retinal necrosis (ARN) is a rare, sight-threatening eye disease induced by ocular VZV or HSV infection. The virus and host factors involved in ARN pathogenesis remain incompletely described. We hypothesize an underlying genetic defect in at least part of ARN cases. Methods: We collected blood from 17 patients with HSV-or VZV-induced ARN, isolated DNA and performed Whole Exome Sequencing by Illumina followed by analysis in Varseq with criteria of CADD score > 15 and frequency in GnomAD < 0.1% combined with biological filters. Gene modifications relative to healthy control genomes were filtered according to high quality and read-depth, low frequency, high deleteriousness predictions and biological relevance. Results: We identified a total of 50 potentially disease-causing genetic variants, including missense, frameshift and splice site variants and on in-frame deletion in 16 of the 17 patients. The vast majority of these genes are involved in innate immunity, followed by adaptive immunity, autophagy, and apoptosis; in several instances variants within a given gene or pathway was identified in several patients. Discussion: We propose that the identified variants may contribute to insufficient viral control and increased necrosis ocular disease presentation in the patients and serve as a knowledge base and starting point for the development of improved diagnostic, prophylactic, and therapeutic applications.

Metastatic squamous cell carcinoma masquerading as acute retinal necrosis.

Purpose: To describe a case of retinal and optic nerve metastases masquerading as acute retinal necrosis secondary to primary squamous cell carcinoma of the lung. Observations: A 66-year-old male with a history of Stage IV lung cancer, actively on chemotherapy, presented with right eye vision loss, an afferent pupillary defect, and partial visual field deficiencies. Exam revealed vitritis, macula-involving infiltrative retinitis, optic neuritis, and vasculitis of the right eye. The patient was treated empirically for acute viral retinitis with intravitreal foscarnet and ganciclovir injections and oral acyclovir and trimethoprim-sulfamethoxazole. A diagnostic pars plana vitrectomy with vitreous biopsy, intravitreal antivirals and silicone oil fill was performed. The resulting cytology was positive for malignant squamous cell carcinoma. Conclusions and importance: We present a unique case of primary squamous cell carcinoma metastasizing to the retina and optic nerve which masqueraded as an acute viral retinitis. To date, there have not been any reported cases on Pubmed or Google Scholar at publication time of known squamous cell carcinoma metastases to the retina that demonstrated interval growth leading to emergent elevations in intraocular pressure (IOP). This case demonstrates the importance of considering metastasis when encountering an atypical acute retinal necrosis case, as well as bring awareness to the possibility that elevated IOP may be the first sign of interval metastases, despite surgical debulking, in cases involving known tumor metastases to the retina.