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What is Keratoconus?

What is Keratoconus?


What is keratoconus? In simple terms, keratoconus is a progressive eye disease that impacts the shape of the cornea. The cornea is the clear, front window of the eye, and in those with keratoconus, it thins and gradually bulges outward into a cone shape. This abnormal shape can cause blurred vision, light sensitivity, and glares. In this article, we will delve deeper into what keratoconus is, how it affects the eye, its causes, symptoms, diagnosis, treatment options, and the importance of regular eye examinations for those with the condition.

Understanding the Eye: Where and What is Keratoconus?

The cornea, where keratoconus occurs, is the eye's clear, protective outer layer. It serves two significant functions: protecting the eye from dust, germs, and other harmful matter, and refracting light that enters the eye to help focus it onto the retina.

Keratoconus manifests when the cornea, typically round and dome-shaped, begins to thin and gradually bulge into a cone-like shape. This deformation deflects light entering the eye on its way to the light-sensitive retina, leading to distorted vision. It generally affects both eyes and can lead to a significant decrease in the quality of one's vision, making daily tasks like reading, driving, or watching television difficult.

Causes of Keratoconus

The causes of keratoconus are not completely understood, but it is believed that a combination of genetic, environmental, and hormonal factors contribute to the disease. Some research suggests that keratoconus is linked to a reduction in protective antioxidants in the cornea. Without these antioxidants, the collagen weakens and the cornea bulges out.

Genetics also seem to play a role in keratoconus. It is more common in individuals with a family history of the condition. Additionally, certain systemic disorders, such as Down syndrome, Ehlers-Danlos syndrome, and osteogenesis imperfecta, are associated with a higher incidence of keratoconus. Environmental factors, such as excessive eye rubbing and prolonged exposure to ultraviolet rays, can also contribute to the thinning of the cornea and the progression of the disease.

Symptoms of Keratoconus

The symptoms of keratoconus typically start to appear in the late teens or early twenties, and may vary depending on the stage and severity of the disease. In the early stages, individuals may experience slight blurring and distortion of vision, increased sensitivity to light and glare, and frequent changes in eyeglass prescriptions.

As the condition progresses, the cornea bulges and thins, leading to increased distortion of vision, along with increased astigmatism and nearsightedness. Individuals may find that their prescription changes frequently. In advanced stages, they may also see streaks, halos around lights at night, and a white or a grayish ring around the cornea.

How is Keratoconus Diagnosed?

Keratoconus is diagnosed through a comprehensive eye exam. If keratoconus is suspected, the eye doctor may perform a number of tests to confirm the diagnosis. These tests may include a slit-lamp examination, which involves using a low-power microscope with a high-intensity light source to examine the front and back of the eye.

The eye doctor may also use a corneal topographer to obtain a detailed image of the curved surface of the cornea. This can help identify the characteristic patterns of keratoconus. In addition, the eye doctor may measure the thickness of the cornea, as keratoconus often results in a thin cornea.

Treatment Options for Keratoconus

The treatment for keratoconus depends on the severity of the condition and how quickly it is progressing. In the early stages, vision problems can often be corrected with eyeglasses or soft contact lenses. As the disease progresses and the cornea becomes increasingly thin, rigid gas permeable contact lenses may be recommended to create a smooth, clear surface for light to enter the eye.

In more advanced cases, a procedure known as corneal cross-linking may be performed to slow or halt the progression of keratoconus. This procedure involves applying a vitamin B solution to the eye followed by treatment with ultraviolet light. In the most severe cases, a corneal transplant may be necessary.

The Importance of Regular Eye Examinations in Keratoconus

Regular eye examinations are crucial for individuals with keratoconus. Because the disease can progress quickly, frequent check-ups can help ensure that the condition is being managed effectively and that any changes in vision are corrected as soon as possible. Regular eye exams also allow the eye doctor to monitor the health of the cornea and the progression of the disease.

During these examinations, the eye doctor can also provide advice on managing symptoms and avoiding activities that could worsen the condition. For example, they may recommend avoiding eye rubbing, wearing UV-protecting sunglasses, and using lubricating eye drops to help manage dry eyes.


Keratoconus is a complex eye disease that causes the cornea to thin and bulge into a cone-like shape, leading to distorted vision. While the exact causes of keratoconus are not fully understood, it is believed that a combination of genetic, environmental, and hormonal factors are involved. Regular eye examinations are crucial for managing the condition and ensuring the best possible vision outcomes.

If you suspect you may have keratoconus, contact Maple Eye and Laser Center at our office in White Plains or Manhattan, New York. Call (914) 948-5157 to book an appointment today.