SARS-CoV-2 Also Targets the Nervous System of Eyes, Causing Ocular Neuroinflammation

Medical News: Since the emergence of COVID-19, the world has primarily focused on its respiratory complications. However, mounting evidence suggests that SARS-CoV-2 does not restrict itself to the lungs. It can infiltrate various organs, including the nervous system of the eyes, leading to neuroinflammation and other ocular complications. Recent research from the Department of Glaucoma, The Second Hospital of Jilin University, Changchun, China, highlights this alarming aspect of the virus, shedding light on its impact on intraocular tissues. This Medical News report explores the latest findings, the mechanisms involved, and the broader implications for eye health.


SARS-CoV-2 Also Targets the Nervous System of Eyes, Causing Ocular Neuroinflammation

The Link Between SARS-CoV-2 and Ocular Neuroinflammation
Scientists have long been aware that SARS-CoV-2 exhibits neurotropism, meaning it can target nerve tissues. A key player in this invasion is the angiotensin-converting enzyme 2 (ACE2) receptor, which is widely present in various ocular structures, including the retina, cornea, conjunctiva, and aqueous humor. When the virus binds to ACE2 receptors in the eyes, it can trigger a cascade of inflammatory responses, leading to conditions such as optic neuritis, glaucoma, retinal inflammation, and vascular occlusions.
 
The study conducted by Chinese researchers outlines how ocular neuroinflammation stems from persistent immune activation. It is not just a localized effect but part of a larger systemic response that can lead to prolonged eye-related symptoms even after recovery from COVID-19.
 
Key Findings: How COVID-19 Affects Eye Health
The study provides compelling evidence on the variety of ocular complications linked to SARS-CoV-2 infection:
 
1. Ocular Surface Manifestations
One of the earliest and most reported ocular symptoms of COVID-19 is conjunctivitis, also known as pink eye. It presents as eye redness, excessive tearing, burning sensations, itching, and discomfort. Studies have shown that the virus can be found in tear fluid, indicating that the eyes can serve as both an entry and exit route for SARS-CoV-2. Some patients develop prolonged conjunctival irritation even after clearing the virus, suggesting a lingering inflammatory response.
 
In addition to conjunctivitis, COVID-19 patients have reported foreign body sensations, photophobia (light sensitivity), and dry eye syndrome. These symptoms arise due to the virus-induced inflammation affecting the tear-producing glands and ocular surface.
 
2. Retinal and Optic Nerve Involvement
SARS-CoV-2’s ability to cross the blood-retinal barrier allows it to infiltrate the retinal tissues, leading to a series of inflammatory events. Some of the reported retinal complications include optic neuritis, retinal vasculitis, and microvascular occlusions. These conditions can cause partial or complete vision loss if left untreated.
 
Fundoscopic e xaminations in COVID-19 patients have revealed alarming signs of optic nerve swelling, hemorrhages, and retinal ischemia. In some cases, patients develop persistent vision impairment, blind spots, or reduced color perception.
Studies have also detected SARS-CoV-2 RNA in the retinas of deceased patients, providing concrete evidence that the virus directly invades these tissues. The inflammatory damage inflicted by the virus can mimic that seen in autoimmune diseases like multiple sclerosis and lupus, further complicating diagnosis and treatment.
 
3. Glaucoma and Elevated Intraocular Pressure (IOP)
Post-COVID-19 cases of acute angle-closure glaucoma have raised concerns among ophthalmologists. The inflammatory response triggered by the virus can cause swelling and fluid buildup in the eye, leading to increased intraocular pressure (IOP). If untreated, this can result in permanent optic nerve damage and blindness.
 
Furthermore, research suggests that COVID-19 patients on corticosteroid treatments may be at an increased risk of developing steroid-induced glaucoma. High doses of steroids, often used to manage severe COVID-19 cases, can disrupt the eye’s drainage system, exacerbating IOP-related issues.
 
4. Long-Term Ocular Effects and Post-COVID Syndrome
Even after recovery, some individuals experience lingering ocular discomfort, visual disturbances, and neuroinflammatory responses in the retina. Post-COVID syndrome (Long COVID) has been linked to persistent eye issues such as blurred vision, prolonged dryness, excessive floaters, and difficulty focusing on objects.

Optical Coherence Tomography (OCT) scans of recovered patients have revealed structural changes in the retinal and optic nerve layers, suggesting long-term damage. These findings are concerning as they indicate that COVID-19 could contribute to the development of neurodegenerative eye diseases in the future.
 
Mechanisms Behind Ocular Neuroinflammation
The study explains that the virus’s effects on the nervous system of the eyes result from several interrelated mechanisms:
 
-Direct Viral Invasion - SARS-CoV-2 can travel through the trigeminal and optic nerves, reaching the eyes from the nasal cavity and brainstem.
 
-Cytokine Storm - The inflammatory response to COVID-19 involves excessive release of pro-inflammatory cytokines (IL-6, TNF-α, IFN-γ), which can exacerbate damage to ocular tissues.
 
-Blood-Retinal Barrier (BRB) Disruption - Similar to the blood-brain barrier, the BRB protects the eyes from harmful substances. However, SARS-CoV-2 can break through this barrier, leading to retinal inflammation and microvascular damage.
 
-Immune Dysregulation - Autoimmune reactions triggered by COVID-19 may contribute to chronic inflammatory conditions like uveitis and optic neuritis.
 
Clinical Implications and Future Research
These findings emphasize the need for routine eye examinations in COVID-19 patients, especially those with prolonged symptoms. Ophthalmologists should consider COVID-19 as a potential underlying cause of new or worsening ocular conditions.
 
The study also calls for further research into long-term eye complications, particularly in individuals experiencing Long COVID. Scientists are exploring targeted anti-inflammatory treatments and neuroprotective therapies that could mitigate the damage caused by SARS-CoV-2.
 
Conclusion
The notion that COVID-19 primarily affects the lungs is outdated. This study from Jilin University, China, provides critical insights into how SARS-CoV-2 targets the nervous system of the eyes, leading to ocular neuroinflammation, optic nerve damage, and lasting visual complications. As research advances, the medical community must integrate ocular health into post-COVID care strategies to ensure early detection and intervention.
 
The study findings were published in the peer-reviewed journal: Frontiers in Immunology.
https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2025.1515768/full
 
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