Ophthalmic manifestations and management considerations for emerging chemical threats.

Chemical agents have been utilized for centuries in warfare and pose a health threat to civilians and military personnel during armed conflict. Despite treaties and regulations against their use, chemical agent exposure remains a threat and measures to understand their effects and countermeasures for systemic and organ-specific health are needed. Many of these agents have ocular complications, both acute and chronic. This mini-review focuses on key chemical agents including vesicants (mustards, lewisite), nerve agents (sarin, VX), knockdown gasses (hydrogen cyanide), and caustics (hydrofluoric acid). Their ophthalmic manifestations and appropriate treatment are emphasized. Acute interventions include removal of the source and meticulous decontamination, as well as normalization of pH to 7.2-7.4 if alteration of the ocular pH is observed. Besides vigorous lavage, acute therapies may include topical corticosteroids and non-steroid anti-inflammatory therapies. Appropriate personal protective equipment (PPE) and strict donning and doffing protocols to avoid healthcare provider exposure are also paramount in the acute setting. For more severe disease, corneal transplantation, amniotic membrane graft, and limbal stem cell transplantation may be needed. Orbital surgery may be required in patients in whom cicatricial changes of the ocular surface have developed, leading to eyelid malposition. Multidisciplinary care teams are often required to handle the full spectrum of findings and consequences associated with emerging chemical threats.

Ophthalmic implications of biological threat agents according to the chemical, biological, radiological, nuclear, and explosives framework.

As technology continues to evolve, the possibility for a wide range of dangers to people, organizations, and countries escalate globally. The United States federal government classifies types of threats with the capability of inflicting mass casualties and societal disruption as Chemical, Biological, Radiological, Nuclear, and Energetics/Explosives (CBRNE). Such incidents encompass accidental and intentional events ranging from weapons of mass destruction and bioterrorism to fires or spills involving hazardous or radiologic material. All of these have the capacity to inflict death or severe physical, neurological, and/or sensorial disabilities if injuries are not diagnosed and treated in a timely manner. Ophthalmic injury can provide important insight into understanding and treating patients impacted by CBRNE agents; however, improper ophthalmic management can result in suboptimal patient outcomes. This review specifically addresses the biological agents the Center for Disease Control and Prevention (CDC) deems to have the greatest capacity for bioterrorism. CBRNE biological agents, encompassing pathogens and organic toxins, are further subdivided into categories A, B, and C according to their national security threat level. In our compendium of these biological agents, we address their respective CDC category, systemic and ophthalmic manifestations, route of transmission and personal protective equipment considerations as well as pertinent vaccination and treatment guidelines.

Outcomes of Combination Systemic and Intravitreal Antiviral Therapy for Acute Retinal Necrosis.

PURPOSE: Determine the efficacy of combination intravitreal and systemic antiviral therapy for the treatment of acute retinal necrosis (ARN) and risk factors impacting visual acuity (VA) and retinal detachment (RD) outcomes. DESIGN: Single-center retrospective case series. PARTICIPANTS: Patients with an ARN diagnosis based on clinical features and polymerase chain reaction confirmation who were treated at a tertiary referral, university-based academic practice. METHODS: Patient records were reviewed for demographic information including age and gender. Snellen VA, disease findings including RD outcomes, optic nerve involvement, and treatments were recorded. Incidence rates of major VA and RD outcomes were calculated based on the number of events and exposure times. Cox proportional hazards regression modeling and survival analyses were used to identify factors related to VA and RD outcomes over time. MAIN OUTCOME MEASURES: Logarithm of the minimal angle of resolution VA, 2-line or more VA gain, severe vision loss (SVL) of 20/200 or worse, RD development, and fellow eye involvement. RESULTS: Twenty-three eyes of 21 patients (11 male, 10 female) were reviewed. Thirteen patients (62%) had herpes simplex virus and 8 patients (38%) had varicella zoster virus. The event rate for 2-line or more VA gain was 0.49 events/eye-year (95% confidence interval [CI], 0.26-0.86 events/eye-year), whereas the rate of SVL was 0.61 events/eye-year (95% CI, 0.34-1.02 events/eye-year). Retinal detachment development was observed at a rate of 0.59 events/eye-year (95% CI, 0.33-1.00 events/eye-year). Thirteen of 23 eyes (57%) demonstrated RD with a mean time of 120 days after ARN diagnosis. With each additional quadrant of retina involved, a greater risk of RD development over time was observed (hazard ratio, 2.21; 95% CI, 1.12-4.35). Nine percent of eyes progressed with additional quadrantic involvement, despite combination systemic and intravitreal antiviral therapy; however, none of the 19 patients demonstrating unilateral ARN showed fellow-eye involvement after initiation of therapy. CONCLUSIONS: Combination intravitreal and systemic antiviral therapy for ARN can be effective in improving VA and limiting retinitis progression. Each additional quadrant of retina involved was associated with a 2.2-fold greater risk of RD, which may impact monitoring, timing of intervention, and patient counseling.

Toxoplasmosis chorioretinitis mimicking acute retinal necrosis associated with local corticosteroid.

BACKGROUND: The cases discussed highlight the atypical presentation and diagnostic dilemmas of toxoplasmosis with fulminant retinal necrosis and the potentially devastating visual outcomes of toxoplasma chorioretinitis following local corticosteroid exposure. CASE PRESENTATION: We report a series of three patients who presented with toxoplasmosis mimicking severe acute retinal necrosis. Patients were between 59 and 77 years old and had been exposed to local corticosteroids preceding our evaluation. All patients demonstrated diffuse retinal whitening with severe vision loss on presentation. Polymerase chain reaction testing (PCR) was diagnostic in two patients, and histopathologic examination of a vitrectomy specimen was diagnostic in one patient. All cases of retinitis resolved with anti-parasitic medication; however, visual acuity failed to improve in all patients due to disease severity and presentation. CONCLUSIONS: Local corticosteroid injection may trigger or exacerbate toxoplasmosis chorioretinitis, leading to fulminant retinal necrosis and severe vision loss. Toxoplasma chorioretinitis should be considered in the differential diagnosis of patients presenting with clinical features of acute retinal necrosis, particularly following local corticosteroid injection regardless of their baseline systemic immune status. Diagnostic vitrectomy may be helpful in patients in whom PCR testing is negative and ocular toxoplasmosis is suspected.

Microsporidial stromal keratitis and endophthalmitis in an immunocompetent patient.

PURPOSE: The purpose of this study is to report a case of microsporidial endophthalmitis after penetrating keratoplasty in a healthy patient and discuss the management. METHODS: This is a case report. RESULTS: A 69-year-old healthy male underwent penetrating keratoplasty for corneal scar secondary to herpes stromal keratitis. He presented with features of acute graft rejection 3 years later. After failure of medical management, a repeat full thickness keratoplasty was performed. Pathologic examination of the corneal specimen showed microsporidia. The patient then developed a chronic endophthalmitis, and a vitreous tap and injection followed by pars plana vitrectomy were performed. Pathologic examination of tissue showed microsporidia. CONCLUSIONS: Microsporidia are being increasingly identified as the cause of stromal keratitis. This is the first report of microsporidial endophthalmitis in a patient without underlying systemic illness.