Retinal Vessel Analysis: A Potential Tool for Detecting Long COVID

Recent studies have indicated a significant connection between COVID-19 and changes in retinal blood vessels.

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Eye health can reflect one’s overall physical condition, and recent studies have indicated a significant connection between COVID-19 and changes in retinal blood vessels. Since the onset of the COVID-19 pandemic, many individuals have been affected by various long-COVID symptoms, especially concerning cardiovascular issues.

In July, the Angiogenesis journal published a study in which researchers conducted a retinal vessel analysis on 41 long-COVID patients to assess microvascular endothelial function. The body’s endothelium lines blood vessels and lymphatic vessels.

The results revealed that long-COVID patients exhibited persistent endothelial dysfunction compared to a healthy control group without a COVID-19 infection. Typically, the retinal vessels would dilate when exposed to flickering light. However, this response significantly diminished in patients with a prolonged COVID-19 infection, particularly in the microvascular reaction to light stimulation. Additionally, the researchers found through retinal microvascular analysis of long-COVID patients that, in comparison to the healthy control group, their retinal arterioles were significantly narrower.

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The researchers also found that changes in endothelial function were linked to inflammation; the higher the levels of inflammatory biomarkers measured in participants’ blood, the more pronounced these changes.

One of the effects of COVID-19 is vascular alterations, specifically the impact on the inner lining of blood vessels, resulting in inadequate blood supply to organs. The researchers noted that 90 percent of endothelial cells reside in the microcirculation, and the blood vessels within the eyes can offer insights into the condition of the body’s microvasculature, providing a noninvasive way to assess endothelial health.

Dr. Chieh-Yu Chen, a cardiovascular specialist at Taiwan’s Cathay General Hospital, stated in an article that the omicron variant of the COVID-19 virus currently presents a lower mortality rate. Nevertheless, it exhibits a higher transmission rate than previous strains and demonstrates a more pronounced phenomenon of immune evasion. This implies that there is still a risk of infection even after vaccination. While the majority of cases result in mild symptoms, some individuals may experience lingering symptoms, referred to as long COVID, which can affect various organ systems, including the respiratory, cardiovascular, neurological, renal, endocrine, musculoskeletal, gastrointestinal, and integumentary, and can even result in multisystem inflammatory syndrome.

9 Repercussions of Long COVID on Different Body Systems

1. Respiratory

A systematic review of 6,770 long-COVID patients indicated that many COVID-19 survivors experience pulmonary sequelae. These may include impaired lung function and diffusion capacity. When examined with CT scans, 34 percent of the patients exhibited ground-glass opacities, referring to the hazy, white, dense areas in the lungs in a CT scan, and 32 percent exhibited lung scarring. Furthermore, the prevalence of these conditions did not decrease over time.

2. Cardiovascular

A study published in Nature Medicine in 2022 analyzed data from over 150,000 COVID-19 patients in the U.S. Department of Veterans Affairs and found that individuals who had contracted COVID-19 one year prior had a significantly increased risk of developing 20 different cardiovascular diseases. This increased risk was evident even among patients not hospitalized for COVID-19.

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The results revealed that, compared to a control group composed of veterans who had not contracted the virus during the same period, there was an increase of 45.29 cases of cardiovascular complications per 1,000 COVID-19 patients within 12 months. This increase included 23.48 cases of major adverse cardiovascular events, 19.86 cases of arrhythmia, 11.61 cases of heart failure, 9.88 cases of thromboembolic disorders, and 5.48 cases of cerebrovascular disorders.

Dr. Ziyad Al-Aly, the author of the study and a clinical epidemiologist at Washington University, stated in an email to the Journal of the American Medical Association that the increased risks for heart failure and atrial fibrillation were especially apparent, but the scope of cardiovascular disease involvement was “eye-opening.” The risk was significant across various demographics, including young and older people, males and females, smokers and nonsmokers, and people with or without diabetes. COVID-19 can result in serious long-term cardiovascular disease consequences, most of which are “lifelong conditions.”

Dr. Al-Aly also pointed out: “The risks reported in our paper may appear small but given the large number of people with COVID-19 in the US and globally, these numbers will likely translate into millions of people with heart disease in the US and many more around the world. We need to realize this now and make sure we are prepared and ready to address the needs of these patients.”

3. Nervous

A comprehensive population study published in the renowned Lancet’s eClinicalMedicine journal in 2021 conducted an online survey involving 3,762 long-COVID patients. Among the participants, a striking 85.1 percent experienced brain fog and cognitive dysfunction, 72.8 percent reported both short-term and long-term memory loss, and 78.6 percent of the patients had difficulty with sleep. Other psychological symptoms include language issues (48.6 percent), headaches (77 percent), emotion and mood issues (88.3 percent), and hallucinations (23.2 percent). Notably, many patients had not recovered even after seven months.

4. Renal

A study published in the Journal of the American Society of Nephrology in 2021 revealed a significantly increased risk of kidney disease among COVID-19 survivors. Researchers analyzed data from over 1.72 million individuals within the U.S. Department of Veterans Affairs, and the results indicated that patients who had recovered from COVID-19 were nearly three times more likely to develop end-stage renal disease (requiring kidney transplant or outpatient dialysis) compared to those who had not been infected.

5. Endocrine

The menstrual cycle in women is a marker of health and fertility. A study from Krakow University in Poland suggested that women who reported more COVID-19 symptoms were more likely to report changes in their menstrual cycles. Among 113 women who had contracted COVID-19, approximately 10 percent reported prolonged and disrupted cycle regularity, along with abdominal pain and menstrual headaches.

The researchers believe that COVID-19 virus infection may lead to hypothalamic dysfunction, consequently resulting in menstrual irregularities.

6. Musculoskeletal

Research has found that COVID-19 infection may trigger arthritis, including rheumatoid arthritis. COVID-19 promotes the secretion of inflammatory factors, leading to an overactive immune system and causing arthritis.

7. Gastrointestinal

In December 2022, the BMJ’s Gut published a study that revealed, during a 12-month follow-up period, 59.3 percent of COVID-19 patients previously hospitalized exhibited gastrointestinal symptoms, such as nausea and diarrhea. In contrast, among patients in the control group who had been hospitalized but were not infected with COVID-19, only 39.7 percent experienced gastrointestinal symptoms. As for irritable bowel syndrome, the incidence rate among COVID-19 patients was 3.2 percent, while the control group had an incidence of only 0.5 percent.

Irritable bowel syndrome is a common gastrointestinal disorder characterized by symptoms that include spasms, abdominal pain, bloating, flatulence, diarrhea, and/or constipation. It is a chronic condition that requires long-term management.

8. Skin, Hair, Nails, and Glands

A comprehensive literature review summarized 27 different skin lesions associated with COVID-19 infection, including pernios (16.56 percent), morbilliform exanthema (13.5 percent), vesicular eruption (13.19 percent), urticaria (9.82 percent), erythematous exanthema (7.98 percent), papulosquamous-eruption (5.52 percent), retiform purpura (3.68 percent), and livedo-reticularis lesions (2.76 percent). The appearance of skin lesions after COVID-19 infection is not uncommon and can be attributed to microvascular changes.

9. Multisystem Inflammatory Syndrome (MIS)

A study published in JAMA Network Open in 2022 found that among nearly 170,000 children who contracted COVID-19, 707 developed multisystem inflammatory syndrome in children (MIS-C), with 261 of these cases being severe. The study revealed that male African American children under 12 had higher odds of developing MIS-C. Additionally, obesity was identified as one of the risk factors for multisystem inflammatory syndrome.

6 Habits for Preventing Long COVID

A study published in JAMA Internal Medicine in February indicated that adhering to a healthy lifestyle can significantly reduce the risk of contracting COVID-19. Having five or all six of the following health factors can decrease the risk of long COVID by 49 percent:

1. A healthy body mass index (BMI) between 18.5 and 24.9 (calculated as weight in kilograms divided by height in meters squared).
2. Abstinence from cigarette smoking (including electronic cigarettes).
3. At least 150 minutes of moderate to vigorous physical activity per week, such as running, jogging, cycling, squash, tennis, swimming, resistance training, and brisk walking.
4. High diet quality: Dr. Yuhong Dong, a European virology expert, emphasized in an interview with The Epoch Times that a high-quality diet should primarily consist of whole foods, which are minimally processed. Consuming food in its most natural state ensures the preservation of its full nutritional value.
5. Moderate alcohol consumption (5 to 15 grams per day).
6. Adequate sleep (seven to nine hours per night).