Authors: Chaisiri JumroendararasameSomboon PanyakornRittirak OthongAuraya JumroendararasameWorapot SrimananKun Tipparut12345678910 American Journal of Opthalmology

A B S T R A C T
Purpose: The first reported case of bilateral transient visual field defect, experienced by an ophthalmologist, which developed shortly after COVID-19 vaccination (CoronaVac, Sinovac Biotech Ltd., Beijing, China) and confirmed by computerized automated perimetry.
Observation: The patient is a 42-year-old Thai ophthalmologist. He developed blurred vision within an hour after the second dose of COVID-19 vaccination. We described his self-observed of sequential symptoms, chronologic events, and management steps. The visual field of left congruous hemianopia with respect to vertical midline was detected with computerized automated perimetry. The possible mechanism could be related to an acute vaso- spasm of the artery in the postchiasmatic visual pathway, triggered by COVID-19 vaccine,
Conclusion and importance: With increasing use of the COVID-19 vaccine in the near future, it would be prudent for medical staff and ophthalmologists to be considered and aware of this associated condition.

1. Introduction
   Since the global spreading of the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-
2. 2) in December 2019, the situation hasworsened, resulted in the pandemic declaration by the World Health Organization (WHO) on March 11th, 2020.1 The expedited development and approval of Covid-19 vaccine is an inevitable solution. Many possible side effects of the Covid-19 vaccine have been reported including fever, pain, weakness and paralysis.2 Vision related adverse
   effects can be found and had been reported after other vaccination such as influenza,3 measles, rubella,4 rabies,5 tuberculosis,6 hepatitis B,7 meningitis,8 anthrax9 and tetanus10 vaccine. However, to the best of ourknowledge, there was no report of visual field defect, developed shortly after COVID-19 vaccination (CoronaVac, Sinovac Biotech Ltd., Beijing, China) which was occurred and had been self-detected by an ophthal- mologist (CJ).
3. Case report
   A 42-year-old Thai male ophthalmologist (CJ), otherwise healthywith a history of good controlled dyslipidemia for 10 years, using nRosuvastatin 20 mg. daily. He received the first dose of Corona Vac(Sinovac Biotech Ltd., lot number A2021010041) on March 24th, 2021without serious adverse reactions, only mild muscle sore of the injection site at left deltoid muscle. The second dose of Coronac Vac (lot number J202103002) was injected on April 21, 2021. He developed blurred
   vision within an hour after vaccination. Sequential symptoms, chrono-logic events, and management steps were described as followed. At12.50 p.m., the patient had vaccination, and was closely observed in adesignated area of the hospital for 30 minutes without any adverse
   events. Ten minutes later he noticed having a blurred vision starting atthe center of his visual field, foggy in character. Scotoma enlargedwithin a couple of minutes before it obscured the left side of his visualfield. He reported as looking through the watery scene but it was notdark. There was no associated headache or any weakness. The patientwent back to the ophthalmology department 10 minutes after he had the