Visual Field Defect following CoronaVac (SinoVac) COVID-19 Vaccination : a case report

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Lerprat Mangkornkanokpong



Globally, as of 21 May 2021, According to official data published by the World Health Organization, more than 165 million cases have been confirmed to be infected with COVID-19 (coronavirus disease starting in 2019) , causing over 3.4 million deaths.1

CoronaVac, also known as the Sinovac COVID-19 vaccine,  2 is an inactivated virus COVID-19 vaccine developed by the Chinese company Sinovac Biotech. 3  It was Phase III clinical trials in Brazil,4 Chile,  5 Indonesia6 the Philippines7 and Turkey 8 and relies on traditional technology similar to BBIBP-CorV and BBV152, other inactivated-virus COVID-19 vaccines. 9 CoronaVac does not need to be frozen and both the final product and the raw material for formulating CoronaVac can be transported refrigerated at 2–8 °C (36–46 °F), temperatures at which flu vaccines are kept. 10  

In February, Thailand approved emergency use  11 and started its vaccination program on 27 February.  12 As of May, Thailand had received 3.5 million doses with another 2 million to arrive later that month.  13

          According to “Guildlines for adverse reactions after vaccination in case of reactions associated with vaccination stress stroke-like syndrome”, When vaccinating a large number of people at the same time there will have a chance to encounter adverse reactions. Due to various news reports of vaccine side effects cause a lot of anxiety and vaccinated process can cause stress. That called “Immunization Stress-Related Response (ISRR)”. The symptoms such as faint, Abdominal pain, nausea, blurred vision, high blood pressure and increase heartrate. It is more common in women than men, especially in young people. Normal neuroimaging study. Symptoms can be completely healed in 1-3 days.14

On April 25, 2021, the Institute of Neurology and the Neurology Society of Thailand learned about the side effects of vaccination against COVID-19, that the result would be numbness, weakness, blurred speech or blurred vision. Currently, the mechanism of symptoms is currently being examined, according to the World Health Organization (WHO). Symptoms can be completely healed in under 24 hours, while the least may be up to 72 hours.15

The adverse effects of the inactivated CoronaVac vaccine have not been fully characterized yet. Another strange side-effect is the one which has impaired some people's vision right now. According to some case studies, getting inoculated could leave some people with hazy or blurred vision for a couple of days. 16

             Therefore, the researcher interested in presenting Case report which have been followed for 1 week and 1 month with visual field defect without any pathology.


Case presentation

This study was performed in accordance with the tenets of the Declaration of Helsinki, The Council for International Organizations of Medical Sciences (CIOMS) and International Conference on Harmonization’s Good Clinical Practice Guidelines  (ICH GCP). Approval to conduct this study was obtained from the Institutional Review Board Royal Thai Army Medical Department No.IRBTA724/2564.

A 35 year old healthy male present with sudden painless blur vision both eyes 26 hours after received the second dose of CoronaVac (SinoVac) vaccine in May 2021. He has no history of drug use, alcohol drinking, caffeine intake or smoking. He drink 1.5 litres of water before and 0.5 litres after receive the vaccine. According to the records, the patient receive the first dose of vaccine 4 weeks before. After receiving the first dose of vaccine, he only feels a little bit itching about 30 minutes.

          Extensive ophthalmic examination were conducted. The best corrected visual acuity (BCVA) was 20/20 both eyes by EDTRS charts. Intraocular pressure (IOP) ,using noncontact airpuff tonometry, was 9 mmHg on right eye and 8 mmHg on left eye. Slit lamp eye examination, fundus examination, color vision test, Optical coherence tomography (OCT) macular were normal (Figure 1)

          On Computerized visual field (CTVF) 30-2, Humphy Field Analyzer HFA750i ,  we found Right incongruous homonymous hemianopia (Figure 2). Laboratory investigations include Complete blood count,  Blood urea nitrogen ,Creatinine blood, Blood electrolytes, Blood lipid profile, Dextrostix and Fasting blood sugar were normal. Echocardiogram, Brain Computerized Tomography Scan, Computed Tomographic Angiography, Brain Magnetic Resonance Imaging and Magnetic Resonance Angiography show normal study. The patient receive Aspirin(81mg),Plavix(75mg),Atorvastatin(40mg), Intravenous 0.9%Normal saline solution daily for 7 days. He was closely followed up daily. Seven days (Figure 2-8) and one month later (Figure 9)  CTVF 30-2 still Right incongruous homonymous hemianopia visual field defect.

              “Right incongruous homonymous hemianopia” consider a left postchiasmal lesion. The more posterior the cerebral lesion (occipital lobe), the more symmetric (congruous) the homonymous hemianopsia will be.17 In which in this patient no such pathology was found.             From such events, the researcher still cannot find an about the visual field defect in this patient because of1) Even though the first injection was fine, the visual field defect occurred after received the second dose of vaccine. This might show that it is not related to the patient himself.2) No risk or pathology was found on any investigation. (If it is caused by Vasospasm or ISRR, the symptoms will completely healed in 24 - 72 hours)3) On the day of vaccination, 159 persons who got this same vaccinated was no abnormal symptom. It was unlikely to be associated with abnormal vaccine storage or transportation.4) If it is caused by preexisting disease of the patient, there should be any pathology found on imaging study such as old infarction in brain.             This paper follow up about 7 days so we continued to monitor the CTVF 30-2 until changed which should be able to present academic work again.



The patients in this manuscript have given written informed consent to the publication of their case details. The author wishes to thank Dr. Pipat Kongsap for data management.


Conflict of interest

Nothing to disclose.



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Case Report


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