Bilateral Simultaneous Central Retinal Vein Occlusion Secondary to COVID-19: A Case Report.

Herein, we report a case of bilateral simultaneous central retinal vein occlusion (CRVO) secondary to coronavirus disease 2019 (COVID-19). A 48-year-old man, with hypertension, type 2 diabetes mellitus, and stage 4 chronic kidney disease, diagnosed with COVID-19 1 month ago presented to the ophthalmology department with blurred vision in both eyes for 2 weeks. Ocular examination revealed a classic clinical presentation of CRVO in both eyes. Optical coherence tomography revealed increased central macular thickness with intraretinal and subretinal fluid in both eyes. Laboratory data revealed elevated D-dimer and C-reactive protein (CRP) levels. The levels of other hypercoagulability markers were normal. The patient received intravitreal anti-vascular endothelial growth factor therapy in both eyes, followed by regular follow-up every month until complete resolution of symptoms and gradual improvement of the retinal vascular appearance. COVID-19 can cause a variety of coagulation abnormalities and thromboembolic complications such as bilateral simultaneous CRVO. Clinicians and patients should be aware of ocular symptoms and presentations that are probably associated with COVID-19.

Poloxamer-188 Adjuvant Efficiently Maintains Adaptive Immunity of SARS-CoV-2 RBD Subunit Vaccination through Repressing p38MAPK Signaling.

Poloxamer-188 (P188) is a nonionic triblock linear copolymer that can be used as a pharmaceutical excipient because of its amphiphilic nature. This study investigated whether P188 can act as an adjuvant to improve the immunogenicity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) receptor binding domain (RBD) subunit vaccine. BALB/c mice were vaccinated twice with the RBD antigen alone or in combination with P188 or MF59 (a commercial adjuvant for comparison purposes). The resulting humoral and cellular immunity were assessed. Results showed that P188 helped elicit higher neutralizing activity than MF59 after vaccination. P188 induced significant humoral immune response, along with type 1 T helper (Th1) and type 2 T helper (Th2) cellular immune response when compared with MF59 due to repressing p38MAPK phosphorylation. Furthermore, P188 did not result in adverse effects such as fibrosis of liver or kidney after vaccination. In conclusion, P188 is a novel adjuvant that may be used for safe and effective immune enhancement of the SARS-CoV-2 RBD antigen.