What is Ophthalmic Manifestations of Coronavirus (COVID-19)?
Starting in December 2019, COVID-19, caused by the highly contagious virus SARS-CoV-2, turned into a worldwide pandemic. Early reports suggested that eye redness and irritation were common symptoms in COVID-19 patients, pointing towards conjunctivitis (inflammation of the eye’s outermost layer) as a possible effect of the virus. More recent observations show links between COVID-19 and various eye diseases dependent on the uvea (the middle layer of the eye), the retina vessels, and diseases affecting the optic nerve.
During the SARS outbreak of 2003, a similar type of virus was found in tear samples from patients in Singapore. Lack of eye protection was seen as a main risk factor for passing on the SARS virus from patients to healthcare workers in Toronto, suggesting that respiratory illnesses can potentially be spread through tears or other eye secretions. There are similar worries for SARS-CoV-2, especially among eye doctors and other healthcare workers who are usually the first to evaluate potential COVID-19 symptoms.
Dr Li Wenliang, an eye doctor, was one of the first to air concerns about the spread of the coronavirus among Chinese patients. Sadly, he died from COVID-19. It is believed that he caught the virus from a patient with glaucoma (an eye condition) who showed no symptoms of the virus.
What Causes Ophthalmic Manifestations of Coronavirus (COVID-19)?
SARS-CoV-2, the virus that causes COVID-19, is a type of coronavirus with a unique structure. It began spreading in Wuhan, a region in China. The virus can be spread through direct contact with mucous membranes, like the ones found in your eyes.
Coronaviruses have been known to cause serious eye diseases in animals, such as inflammation of the uvea (the middle layer of the eye), retinitis (inflammation of the retina), vasculitis (inflammation of blood vessels), and optic neuritis (inflammation of the optic nerve) in cats and mice. However, in humans, eye problems due to coronaviruses like SARS-CoV-2 are usually mild and not very common, but the number of people with eye issues who also have COVID-19 is increasing.
No eye problems have been reported in people who had Middle East respiratory syndrome (MERS) or the original SARS. However, the SARS virus was found once in eye fluids. Additionally, other types of coronaviruses have been noted to cause viral conjunctivitis (pink eye) in humans.
Risk Factors and Frequency for Ophthalmic Manifestations of Coronavirus (COVID-19)
On April 4, 2020, the World Health Organization (WHO) informed that there were over 1.2 million confirmed cases and nearly 70,000 deaths worldwide from COVID-19. In the previous 24 hours alone, there were approximately 80,000 new confirmed cases. The Centers for Disease Control and Prevention (CDC) reported nearly 340,000 cases and about 9600 deaths in the United States by that date.
Around a year later, on April 16, 2021, the global death toll surpassed 3 million. The severity of the pandemic became clear when considering the rate at which lives were lost. The first million deaths occurred over 8.5 months since the first fatality in China. It took 3.5 months to reach 2 million deaths and just 3 months to exceed 3 million deaths.
By December 23, 2021, the US had reported over 51 million confirmed cases of COVID-19 and more than 800,000 deaths. The WHO documented over 276 million confirmed cases and about 5.4 million deaths globally. Additionally, more than 8.6 billion vaccine doses were given globally. The top countries with the highest COVID-19 infections were the United States, India, Brazil, the United Kingdom, Russia, Turkey, and France.
Various mutations of the SARS-CoV-2 virus occurred worldwide, leading to different variants, including but not limited to:
- The B.1.1.7 variant found in the United Kingdom in early 2020
- The B.1.526 variant discovered in the United States in November 2020
- The B.1.525 variant located in the United Kingdom and Nigeria in December 2020
- The B.1.351 variant in South Africa in late 2020
- The Delta variant (B.1.617.2), which spread across over 60 countries and became the predominant strain worldwide by August 2021
- Most recently, the Omicron variant (B.1.1.529) was designated a variant of concern in November 2021 after cases emerged from Botswana and South Africa, which showed rapid and exponential spread.
At the beginning of the pandemic, it was believed that eye-related symptoms of COVID-19 were less common. Only 0.8% out of 1099 patients displayed signs of conjunctival congestion from December 2019 through January 2020. However, recent data shows a noticeably higher instance of eye symptoms. A 2021 study reported that over 11% of 7300 COVID-19 patients displayed eye symptoms. The most common among these symptoms was conjunctivitis.
Another study involving 38 COVID-19 patients found 12 individuals reporting eye symptoms. These symptoms were redness of the eyes (3 patients), swelling (7 patients), excessive tearing (7 patients), or increase in eye secretions (7 patients). Among those with eye symptoms, 2 were found to have SARS-CoV-2 in their eye secretions. Patients displaying eye-related symptoms had higher white blood cell and neutrophil counts, higher C-reactive protein, and elevated levels of procalcitonin and lactate dehydrogenase.
In another study with 30 COVID-19 patients, one patient had SARS-CoV-2 in their eye secretions as confirmed through a swab test. This patient, however, did not show severe fever or respiratory symptoms during testing. Out of the eye-related symptoms of COVID-19, conjunctivitis and keratoconjunctivitis were the most common in adults. The most common eye-related issues were irritation of the conjunctiva, followed by double vision and cotton wool patches.
Signs and Symptoms of Ophthalmic Manifestations of Coronavirus (COVID-19)
The impact of COVID-19 on the eyes can vary a lot, with studies showing that between 2% and 32% of COVID-19 patients have eye-related problems. This highlights the need for more research into how COVID-19 can affect the eyes.
Firstly, some people with COVID-19 might experience red eyes, irritation, a foreign body sensation, tearing, and a discharge from the eyes, among other symptoms. These can be early signs of acute conjunctivitis. This condition is more common in severe cases of COVID-19 but can also be one of the first indicators of the disease. In some cases, conjunctivitis can be the only symptom.
On examination, signs of mild follicular conjunctivitis might be noticed, such as redness, a discharge, and slight eyelid swelling. There have also been reports of severe hemorrhagic conjunctivitis and formation of a pseudomembrane. Other eye conditions, like epsicleritis, uveitis, and scleritis, can also occur in people with COVID-19.
Regarding the back of the eye, several diseases have been linked to COVID-19, including retinal vein and artery occlusions. There are also reports of acute macular neuroretinopathy, purtscher-like retinopathy, and changes at the inner plexiform and ganglion cell layer. Some researchers have suggested that monitoring the retinal vein diameter could help track the inflammatory response or damage to the endothelial layer in COVID-19.
The optic nerve, which transmits visual information from the retina to the brain, can also be affected by COVID-19. It’s been suggested that this can happen due to direct invasion of the nerve by the virus, damage to the endothelial cells resulting in ischemia and coagulopathy, or a widespread inflammatory reaction caused by the virus. In more severe cases, strokes affecting the visual pathways have been reported.
Finally, other reports have mentioned the orbital tissues and the ocular adnexa as being affected by COVID-19, often in conjunction with bacterial infection. There haven’t been any reports of the virus directly affecting the nasolacrimal system. Moreover, infants born to mothers with COVID-19 can also have eye-related signs and symptoms.
Testing for Ophthalmic Manifestations of Coronavirus (COVID-19)
Getting a detailed medical history is very important for diagnosing your condition. Your doctor will ask about the symptoms you’ve been experiencing, when they started, and how long they’ve been going on. Following this, an examination of the front part of your eyes would be done using a special instrument known as a slit lamp. This test can confirm if you have conditions such as conjunctivitis (inflammation or infection of the outer membrane of your eyeball and the inner eyelid) or episcleritis (inflammation that happens in the thin layer of tissue that covers the white part of the eye).
Your doctor will also check your visual acuity (the sharpness of your vision), the pressure within your eyes, and your eye’s interior by dilating your pupils. These checks are done to ensure you do not have other severe eye conditions.
Then, they will carefully evaluate the response of your pupils to light and how well you can identify colors. This is crucial to check for potential damage to the optic nerve (the bundle of nerve fibers that transmits visual information from your eye to your brain). Evaluations would also be conducted on your eye movements, which could reveal conditions like nystagmus (an involuntary movement of the eyes) or cranial neuropathies (damaged cranial nerves, which are very important for the functioning of your eye muscles).
Another test you might do is the visual field testing, which can help identify problems related to your field of view, commonly associated with strokes.
The presence of the SARS-CoV-2, the virus that causes COVID-19, can be determined by a test known as reverse transcription polymerase chain reaction (RT-PCR). This test involves using a swab to gently sweep your lower eyelid and collect tear samples as well as secretions from your conjunctiva (the inside of your eyelids). This is the most reliable way to collect tear samples and perform viral testing.
Additional tests may be done on your blood or cerebrospinal fluid (the fluid found within your brain and spine) to check for conditions related to inflammation, autoimmunity, or demyelinating entities (conditions that damage the protective covering of nerve fibers in your brain, optic nerves, and spinal cord). Neuroimaging, which involves taking detailed images of your brain, could supply helpful information, particularly if you have optic neuritis (inflammation that damages the optic nerve), visual field deficits, cranial neuropathies, or other related neurological symptoms.
Your doctor will additionally ask if you’ve recently had a fever, respiratory symptoms, exposure to infected individuals, or any travel history, to determine whether further evaluation is necessary for COVID-19. A thorough examination like this help doctors identify potential cases and ensure the suitable management and precautions are in place.
Treatment Options for Ophthalmic Manifestations of Coronavirus (COVID-19)
According to a report by Chen et al, the condition of a patient suffering from COVID-19 related conjunctivitis (also known as pink eye), improved after treatment with a medication called ribavirin. While this shows potential, it is important to note that this approach has not been widely studied yet. Typically, conjunctivitis due to viral infections, including COVID-19, is believed to get better on its own. Patients usually control symptoms with care at home, using things like artificial tear drops, cold compresses, and ophthalmic ointment. Sometimes, gentle antibiotics are given to avoid bacterial infections, especially for those who wear contact lenses.
The American Academy of Ophthalmology (AAO) has advised eye doctors to only provide urgent or emergency eye care during this COVID-19 period, to lessen the chances of spreading the virus and to save on medical supplies. They have outlined criteria to help make this decision based on how urgently the patient needs care.
At present, studies show that the risk of spreading the virus through eye secretions is low, but we are still learning about the virus. Therefore, it’s strongly recommended that healthcare providers take care to protect their eyes, nose, and mouth when examining patients. Eye care professionals in particular need to be careful due to the close proximity to their patients during examinations.
Eye doctors are advised to use equipment such as the slit lamp breath shields, and also ask their patients to limit their speaking during the examination to minimize the risk of the virus spreading. It’s also essential that any shared equipment is cleaned thoroughly and disposable barriers are used wherever possible.
According to the AAO’s guidelines, routine eye check-ups for chronic conditions and annual exams should be postponed until the COVID-19 situation improves. Urgent cases are instead evaluated through phone interviews with the doctor and/or the patient. Patients who do come in for a clinic visit are checked for fever, cough or breathlessness, recent travel history, and any contact with a COVID-19 patient.
If a patient shows two out of the three symptoms, they are referred for a full medical check-up. If they have COVID-19 or symptoms like fever, cough or breathlessness, they’re examined in a separate room by one healthcare professional. This person should be equipped with full personal protective equipment (PPE) and strictly follow hand hygiene practices.
During the SARS-CoV crisis in 2003, healthcare workers made up about 20% of all infected patients. With COVID-19 as well, healthcare workers are at a high risk. As of April 2021 in Italy, over 100 healthcare workers, including more than 60 doctors, died due to the virus. In the United States, over 3699 healthcare workers died due to COVID-19 by April 7, 2021.
It is vital that frontline healthcare workers wear appropriate protective equipment and that they are monitored regularly for signs of the disease. Patients who don’t exhibit significant symptoms are seen by healthcare workers wearing surgical masks, face shields, gloves, who are also practicing good hand hygiene. If a patient meets any of the risk criteria, healthcare workers should wear full PPE.
Due to the potential risk of droplet spread during eye examinations such as through sneezing, extra precautions are taken to protect healthcare workers. Techniques developed include slit-lamp shields made from laminated plastic sheets, and limiting conversation during consultations. Some institutions have also explored options for reusing surgical masks due to shortages.
In Singapore, healthcare workers were required to report their temperatures twice a day using an online system, in order to track potential symptoms. All overseas or out-of-state travels were required to be reported for review. If any healthcare workers developed symptoms, they were urged to get tested, and based on results, necessary isolation and contact tracing measures were put into place.
Any equipment used during examinations, including the slit-lamp shields, is cleaned with a 70% solution of ethyl alcohol after each patient, as it has been found to help inactivate the coronavirus. If a tool can’t be cleaned with alcohol, a 10% solution of sodium hypochlorite (a type of bleach) is used, as it’s also effective against coronaviruses.
What else can Ophthalmic Manifestations of Coronavirus (COVID-19) be?
The eye symptoms of COVID-19 often show up as conjunctivitis, which can look like conjunctivitis caused by other viruses. There are several other conditions with similar eye symptoms that doctors also consider when diagnosing a patient. These include:
- Conjunctivitis caused by viruses other than COVID-19 (for example, adenovirus)
- Bacterial conjunctivitis
- Allergic conjunctivitis
- An eye condition caused by herpes simplex virus (known as keratitis)
- Anterior uveitis, an inflammation on the middle layer of the eye wall
- Corneal abrasion, which is a scratch or scrape on the eye’s surface
- Foreign body in the eye
- Dry eye syndrome
- “Exposure keratopathy”, a condition seen in patients on a breathing machine (intubated) where the eye’s surface doesn’t get enough protection
- Chemosis, a swelling of the white part of the eye that can occur in very ill patients
What to expect with Ophthalmic Manifestations of Coronavirus (COVID-19)
COVID-19 can sometimes cause conjunctivitis, also known as pink eye, but it usually gets better on its own. However, scientists still don’t fully understand how the virus might affect the eyes in other, potentially long-lasting ways. Some research has indicated that COVID-19 patients who test positive for the virus in samples taken from their eyes might have a worse overall disease outcome.
Looking more closely at the data, researchers found that patients with a higher amount of the virus in their body or more severe initial symptoms were more likely to test positive for COVID-19 in eye samples. These patients also tended to have other health problems, which studies have linked to a worse survival rate over the next ten years.
Researchers have concluded that, although eye-related symptoms of COVID-19 don’t necessarily mean a patient is more likely to die from the disease, they could be an early sign that the patient’s disease severity could shift from moderate to severe. However, more research is needed to fully understand this relationship.
Data also suggests that the virus is unlikely to spread through tears from infected patients. In a recent series of case studies, only one out of 30 confirmed COVID-19 patients had a positive test result from tears. This was supported by another study where, despite testing tear and nose-throat samples at the same time, only the nose-throat swabs came back positive. Still, some data suggests that virus spread through the eyes is possible, especially in patients with a high amount of viruses in their body and active pink eye.
Possible Complications When Diagnosed with Ophthalmic Manifestations of Coronavirus (COVID-19)
Most information about the eye-related symptoms of COVID-19 comes from small groups while studying specific cases over a period of time. Generally, these symptoms go away on their own, but it’s still unclear what potential long-term effects or rate of complications are associated with COVID-19. Some studies have found that a serious fungal infection called mucormycosis could develop in these patients. This is due to the imbalance in the immune system caused by COVID-19 and the use of steroids in its treatment. This risk is particularly high for those who have diabetes.
Another potential complication of COVID-19 is poor tear film quality, which is an essential part of maintaining healthy eyes. This could lead to dry eye syndrome and damage to the surface of the eye. This is particularly likely in patients who have been hospitalized due to COVID-19. It is crucial to quickly recognize and treat any eye-related complications, such as dry eye syndrome in COVID-19 patients. This can prevent any long-term vision problems and can help improve overall comfort and well-being.
Common Eye-Related Symptoms:
- Poor tear film quality
- Dry eye syndrome
- Eye surface damage
- Risk of mucormycosis (fungal infection)
Preventing Ophthalmic Manifestations of Coronavirus (COVID-19)
Keeping diseases from spreading is still very important. This can be done by keeping a safe distance from others, washing hands regularly, and making sure not to touch the eyes and face too much. Even though there are vaccines available and some places are seeing fewer people getting sick, these steps are still critical to stop an increase in cases of COVID-19 and other infectious diseases.
Here are some other things to keep in mind:
- It’s better not to use contact lenses.
- Limit the amount of makeup you apply around your eyes.
- Wear glasses or sunglasses instead.
- Change your sheets, pillowcases, and towels often to keep everything clean and healthy.
