- If you experienced a similar response to Pfizer's COVID-19 vaccine, send an email to chris.melore@https://www.mountaintravel.my.id/ sharing your experience.
Scientists have discovered that Pfizer's COVID-19A vaccine could potentially raise the chances of eye injury, resulting in loss of vision.
The latest research focused particularly on how the vaccine influenced patients' corneas, thefront part of the eyewhich permits illumination to come in
Among 64 individuals, researchers in Turkey examined changes in the cornea's inner layer, known as the endothelium, prior to receiving the first Pfizer vaccination and again two months following the second dose.
Findings showed that receiving both doses of the vaccine resulted in increased corneal thickness, a lower number of endothelial cells in the eye, and greater variability in the size of these specialized cells that make up the endothelium.
In the near term, these modifications indicate that the Pfizer vaccine could briefly impair the endothelium, even though participants did not experience noticeable visual issues throughout the study.
For individuals with healthy eyes, these minor changes are unlikely to impact sight immediately.
Nevertheless, if researchers discover that these changes persist for several years, they might result in corneal edema or impaired vision, particularly in individuals with existing eye conditions or those who have undergone a corneal transplant.
A denser cornea and lower cell count may play a role in eye disorders such as corneal edema, bullous keratopathy, or corneal failure, which can lead to irreversible vision damage in advanced stages, particularly when not addressed.
The scientists cautioned in the research, released on Wednesday in the publicationOphthalmic EpidemiologyThe endothelium needs to be carefully observed in individuals with a low endothelial cell count or those who have undergone a corneal transplant.
An ophthalmologist may employ a specific microscope known as specular microscopy to determine if an individual has a reduced number of endothelial cells.
If you experience blurred vision or eye irritation, this test can also assess the health of your corneal cells.
A reduced number of cells may occur due to aging, eye conditions such as Fuchs’ dystrophy, previous eye surgeries, trauma, or infections. These issues harm the cells responsible for maintaining a clear cornea, and they are not replaced once lost.
More specifically, the research team observed that the Pfizer-BioNTech vaccine led to a patient's cornea increasing in thickness from 528 to 542 micrometers, which is approximately 0.0208 inches to 0.0213 inches. This represents an approximate two-percent rise in thickness.
A cornea that is somewhat thicker is not necessarily dangerous. The cornea may become temporarily thicker because of inflammation, accumulation of fluid, or stress on the endothelium caused by minor illnesses or eye injuries.
If it remains excessively thick for an extended period, such as months or years, it may cause the cornea to become less transparent, possibly impacting eyesight.
The group did not advise against immunization and will continue to perform extended monitoring of individuals to determine if these alterations persist for several months or even years following the injections.
The typical count of endothelial cells, responsible for maintaining the cornea's clarity by removing extra fluid, decreased from 2,597 to 2,378 cells per square millimeter in the research, representing a reduction of approximately eight percent.
Normal levels of endothelial cells vary between 2,000 and 3,000 cells per square millimeter in adults who are in good health, meaning 2,378 falls within a generally safe range for the majority.
Nevertheless, for individuals who initially have a low cell count because of prior eye surgery, an infection, or a medical condition, this loss might pose a greater threat to their eyesight.
Scientists also found that these cells became less consistent following the vaccine, with their variation coefficient—representing each cell's size difference—rising from 39 to 42.
As cells die, surrounding cells expand to occupy the empty spaces, resulting in greater variations in size.
This might indicate that the endothelium is in poorer condition. If this pattern persists over many years, it could impact the cornea's transparency.
Following vaccination, the research observed a reduction in the number of cells maintaining their normal six-sided structure, with the overall percentage decreasing from 50 to 48 percent in the eye's cells.
Normally, healthy endothelial cells have a hexagonal shape, enabling them to fit closely together, similar to a honeycomb structure.
Even though the two-percent decrease was not an obvious indication of harm, it led the group to believe that the cells could be responding to some form of stress during that period of two to three months.
Experts mentioned that their findings also indicated signs that the changes were very likely connected to receiving the vaccine, suggesting it was not merely an incidental result in the testing.
If the indicators of stress and inflammation decrease quickly following the Pfizer vaccine, the effect of these small changes would not be significantly damaging.
To achieve these findings, the team examined 128 eyes, comprising 64 pairs, prior to each individual receiving their COVID vaccine.
They checked in with the group about 75 days following their second dose of the Pfizer-BioNTech vaccine.
The group employed a machine known as Sirius corneal topography to assess the thickness and contour of the corneas, along with another instrument, the Tomey EM-4000 specular microscope, to capture high-resolution images of the endothelial cells in order to evaluate their quantity, size, and form.
Every individual also underwent a comprehensive eye examination, which included assessments of visual clarity, intraocular pressure, and imaging of both the front and back sections of the eye to confirm general ocular well-being.
By analyzing the data collected prior to vaccination versus that obtained afterward, the scientists were able to determine whether the Pfizer vaccine was affecting eye health.
New information regarding possible adverse effects associated with Pfizer's COVID-19 vaccine has contributed to an increasing number of worries that the Trump administration has previously pointed out.
In May, the U.S. Food and Drug Administration (FDA) mandated that Pfizer and Moderna implementexpanded warning labelsconcerns regarding potential heart-related side effects associated with COVID-19 vaccinations.
The previous doses came with warning labels highlighting the uncommon possibility of patients experiencing myocarditis, which is inflammation of the heart muscle, and pericarditis, an inflammation of the protective lining around the heart.
The updated labels extended the caution to specific age groups, especially males aged 16 to 25.
Scientists discovered that this apparently healthy group seemed to face the greatest risk of the rare side effects.
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