COVID-19 in eyes: New case study offers first proof of coronavirus infecting ocular tissue

The novel coronavirus, SARS-CoV-2, mainly spreads through droplet transmission when a person coughs, talks or sneezes. The virus can then enter your body through your mouth or nose. However, scientists have also suggested the eyes to be a possible route of entry and reservoir of the virus after SARS-CoV-2 RNA was found in the tears and conjunctival sac of some patients. Pink eye or mild conjunctivitis has also been seen in some patients with COVID-19. However, experts indicate that the presence of RNA does not mean that the virus was actively replicating inside the conjunctiva; it may have just been the person shedding the virus from the conjunctiva.So far, there hadn’t been any evidence to show that the COVID-19 causing virus indeed affects ocular tissue. But now, a case study done in Wuhan, China, indicates that the COVID-19 causing virus can indeed multiply inside and affect ocular tissue.The study is published in the open-access peer-reviewed journal JAMA Ophthalmology.The studyThe case study involved a 64-year-old woman who had been admitted to the hospital for COVID-19 on 31 January 2020. The woman had typical symptoms of the disease including a dry cough, a fever of 37.8 degree Celsius along with diarrhoea. Her oxygen saturation levels had been 98 percent and she did not show any respiratory or ocular complications during her hospital stay.The woman was discharged around 20 February but by 28 February, she started experiencing pain in the left and then right eye along with loss of visual acuity (ability to clearly discern details and shapes).The woman was diagnosed with acute angle-closure glaucoma and cataract and had to undergo two different surgeries to get her eye pressure under control. During the surgeries, doctors collected samples from the woman’s conjunctiva (tissue that covers the white part or sclera of the eye and the inside of eyelids), iris (the coloured part of the eye) and trabecular meshwork (tissue in the eye that is responsible for draining away aqueous humor from the anterior chamber of eye) and tested them for the presence of the virus.The same samples from another COVID-19 patient were collected. This patient had also recovered from the disease (evident from two negative RT-PCR tests) but he did not have any eye problems.On comparing the two specimens, SARS-CoV-2 nucleocapsid protein was found in the eye samples taken from the glaucoma patient but not from the control patient even though both patients had ACE2 receptors in their eyes.This study shows that SARS-CoV-2 can infect inner ocular tissue too along with the surface of eyes.The authors suggested two possible mechanisms of entry into the eye. First, through the ACE2 receptors present on the surface of the conjunctiva and second, through systemic infection. However, since the patient was already in the recovery stage and did not show IgM antibody or NP antigen in her plasma, the authors indicated that the second route was less likely to be the case.Protecting your eyes Though it may not be possible to stop SARS-CoV-2 from reaching your eyes if you contract COVID-19, there are some ways to prevent the entry of the virus through the eyes. The American Academy of Ophthalmology suggests the following ways to protect your eyes:

• Follow good hygiene and practice social distancing. 
• Avoid touching your face or mouth and do not rub your eyes. If you absolutely have to rub your eyes, use a clean tissue to do it. 
• Avoid the use of contact lenses as it can increase your risk of getting the infection every time you touch your eyes. 
• Make sure to wash your hands if you wear contact lenses or want to rub your eyes. 
• Wearing protective glasses can help you avoid touching your eyes and prevent the entry of virus in your eyes. 

For more information, read our article on Eye symptoms in COVID-19.