Acute-onset central serous retinopathy; This is a literature report   The authors presented a unique case of a healthy (ethnicity) male who presented with unilateral central serous retinopathy (CSR), temporally related to the administration of a COVID-19 vaccine. 2. Case report A 33-year-old healthy male was referred for ophthalmological evaluation due to blurry vision and metamorphopsia in his right eye. He denied flashes, floaters, ocular pain or redness. He did not have any visual symptoms in his left eye. Past ocular history was negative except for mild hyperopic refractive error. Past medical history was only significant for hip surgery post traumatic injury six years prior to presentation. He denied use of any medications including any remote history of corticosteroids. 69 hours before presentation he received the Pfizer-BioNTech mRNA COVID-19 vaccine, after which, he reported soreness at the injection site and fatigue for 24 hours. Since the inception of the pandemic, the patient has experienced no COVID-19 symptoms and had a negative PCR result in November 2020. On exam, his best corrected visual acuity (BCVA) was 20/63 and 20/ 25 in his right and left eye, respectively. Pupils were equally round and reactive to light and accommodation. Intraocular pressure was 10 mmHg in both eyes. Anterior segment exam was within normal limits. Dilated fundus examination was normal in the left eye but revealed loss of foveal reflex and swollen appearance of the macula in the right eye. No hemorrhages or vascular abnormalities were noted. Optical coherence tomography (OCT) of the right eye showed a macular serous detachment of the neurosensory retina with a central foveal thickness (CFT) of 457 um. OCT of the left eye was unremarkable. On fluorescein angiography (FA), a single point of leakage was noted following the classical ink-blot pattern, with progressive expansion of hyperfluorescence emanating from a single point. Consistent with previous reports of CSR,7 9 OCT angiography (OCTA) showed generally attenuated flow signal in the choriocapillaris that colocalized to the area of serous retinal detachment and foci of increased flow signal. After the initial evaluation, the patient was prescribed spironolactone 50mg daily and was evaluated two and three months later. At the two-month visit, BCVA improved to 20/40 and CFT decreased to 325 um. At the three-month visit, BCVA improved to 20/20, CFT decreased to 211 um, OCT showed complete resolution of subretinal fluid, and the patient was asymptomatic.   Discussion: The authors presented a case of acute unilateral CSR that developed shortly after immunization with the Pfizer-BioNTech mRNA COVID-19 vaccine. To the best of their knowledge, this is the first report of an intraocular complication associated with COVID-19 vaccination. They believe it is prudent to consider the immunization as a potential contributor to disease, given 1) the temporal association between immunization and symptom onset, 2) the relatively low incidence of CSR (9.9 per 100,000 individuals) and 3) their cases absence of classical risk factors for CSR development (including a history of exogenous steroid use, recent stressful social history, and type-A personality). while no cases of mRNA COVID-19 vaccine associated CSR have been reported to date, CSR has been associated with vaccinations against influenza, yellow fever, anthrax and smallpox. Still, these cases are rare. In fact, a search of the terms central serous,central serous retinopathy, central serous chorioretinopathy and CSR across all vaccine products by all vaccine manufacturers yielded no results from 1990 to date using the U.S. Centers for Disease Control and Preventions Vaccine Adverse Event Reporting System. Nevertheless, vaccines have also been associated with a host of chorioretinal pathologies beyond CSR. For example, vaccinations against influenza, yellow fever, hepatitis B, and Neisseria meningitidis have been associated with uveitis, acute idiopathic maculopathy, acute macular neuroretinopathy, Vogt-Koyanagi-Harada disease, and multiple evanescent white dot syndrome. The pathophysiology of CSR remains incompletely understood, but the current literature emphasizes the role of a hyperpermeable and thickened choroid, as a result of hydrostatic forces, ischemia, or inflammation. Further evidence suggests endogenous and exogenous glucocorticoids contribute to the development of the choroidal vasculopathy. The role of retinal pigment epithelium dysfunction remains uncertain. Furthermore, CSRs difficult to explain associations with additional risk factorssystemic hypertension, alcohol use, gastroesophageal reflux disease, and sympathomimetic agents offer additional questions about the pathophysiology of disease. There are several possible pathophysiologic mechanisms for the mRNA vaccine to cause CSR. Their hypotheses for possible pathophysiologic mechanisms are divided into three arms, related to increased serum cortisol, free extracellular mRNA, and polyethlene glycol. First, there is an association between CSR and high serum cortisol levels. The authors could not find any data related to serum cortisol levels after mRNA immunizations. However, in one study of a tetanus toxoid vaccination, serum cortisol levels increased acutely nearly two-fold after vaccination. Therefore, it seems reasonable that mRNA immunizations may similarly trigger endogenous glucocorticoid release. On the other hand, studies have consistently demonstrated that inflammatory cyto kines inhibit glucocorticoid receptor expression through decreased receptor translocation and binding affinity. Vaccines, including the extensively studied influenza virus vaccine, induce mild inflammatory responses. Another study showed that pain at injection site and increased body temperature were accompanied by a pro-inflammatory cytokine response.   Conclusions: Acute CSR may be temporally associated with mRNA Covid-19 immunization.; Sender's Comments: Apart from time association (visual symptoms in right eye occurred 69 hours after vaccination with BNT162B2),the information is not enough to establish a causal relationship between the occurrence of the event and the administration of the suspect vaccine in the individual case report.  More data from large population and laboratory research identifying pathophysiologic mechanisms are needed for fully medical assessment.  The impact of this report on the benefit/risk profile of the Pfizer product is evaluated as part of Pfizer procedures for safety evaluation, including the review and analysis of aggregate data for adverse events. Any safety concern identified as part of this review, as well as any appropriate action in response, will be promptly notified to Regulatory Authorities, Ethics Committees and Investigators, as appropriate