The COVID-19 pandemic introduced widespread public health concerns, prompting questions about its potential effects on various bodily systems. Eye health, in particular, has been a focus of public interest. This article explores the current understanding of cataracts and COVID-19, examining whether a connection exists between the two.
Understanding Cataracts
Cataracts involve the clouding of the eye’s natural lens, which is normally clear and helps focus light onto the retina for sharp vision. This clouding causes vision to become hazy or dim, similar to looking through a frosted window. The lens primarily consists of proteins and fibers, and when these begin to break down, they clump together, leading to the cloudy patches that define a cataract.
Common symptoms of cataracts include blurred or foggy vision, increased sensitivity to light and glare, and difficulty seeing at night. Colors may also appear faded or yellowish, and some individuals might experience double vision in one eye or see “halos” around lights. While aging is the most frequent cause, cataracts can also result from eye injury, certain medical conditions like diabetes, or prolonged use of specific medications, such as steroids.
Common Eye Symptoms of COVID-19
COVID-19 can manifest with various eye symptoms, affecting approximately 10% to 32% of infected individuals. The most commonly reported ocular manifestation is conjunctivitis, often referred to as “pink eye.” This condition involves inflammation of the conjunctiva, the membrane lining the inside of the eyelids and covering the white part of the eye.
Conjunctivitis associated with COVID-19 presents with symptoms such as eye redness, itching, excessive tearing, and a watery or sometimes yellow or green discharge. Other reported eye symptoms include light sensitivity, eye pain, and a feeling of having something in the eye. These eye symptoms are temporary and tend to resolve on their own within a few days to two weeks.
Exploring the Link Between COVID-19 and Cataracts
Current scientific understanding does not indicate a direct causal link between the SARS-CoV-2 virus itself and the development of cataracts. The virus primarily affects the respiratory system, and while it can cause acute eye symptoms like conjunctivitis, these are distinct from the gradual clouding of the eye’s lens seen in cataracts. Research is ongoing, but direct viral infection of the lens leading to cataract formation has not been established.
However, indirect considerations relate to certain treatments for severe COVID-19. Corticosteroids, such as dexamethasone, are often administered to hospitalized patients with severe COVID-19 to reduce systemic inflammation and prevent lung damage. Prolonged or high-dose use of these steroids is a known risk factor for developing specific types of cataracts, particularly posterior subcapsular cataracts. This risk is dependent on both the dose and duration of steroid exposure.
While severe systemic inflammation from COVID-19 could theoretically contribute to various ocular issues, a direct pathway to cataract formation due to this general inflammation has not been clearly demonstrated. One reported case described rapid cataract formation in a young individual following a COVID-19 vaccination, which was attributed to systemic inflammation. However, this remains a rare occurrence, and the vast majority of COVID-19 cases do not lead to cataract development.