What Is Keratoconus?

Keratoconus is a rare eye disorder that affects 1 in 1,000 people. In this article, we'll look into its causes, symptoms, and treatment options, shedding light on this rare condition.

Whether you're newly diagnosed or seeking more information, this guide will provide valuable insights to help you navigate your eye health journey.

What is Keratoconus?

Keratoconus is a rare eye disorder that occurs when the transparent outer layer of the eye (cornea) becomes thin and bulges outward like a cone. It causes blurry vision, light sensitivity, double vision, glares, halos, and bad night vision.

Keratoconus usually starts slowly, often in one's teens or 20s. It usually occurs in both eyes and progresses slowly over 10 years or longer before stabilizing.

Although keratoconus can’t be cured or reversed, it can be managed or slowed down. If left untreated, it can lead to permanent vision loss.

What Causes Keratoconus?

Keratoconus occurs when collagen protein fibers in the eye become weak and thin. However, we don’t know exactly why this happens.

Experts believe it’s caused by genetic and environmental factors, including:

• Family history. About 1 in 10 people with keratoconus have a relative who also has it. However, having the genes doesn’t guarantee you’ll get keratoconus.
• Eye rubbing. Physical stress to the cornea weakens the corneal tissue and increases the risk of keratoconus.
• Allergies. Allergic reactions can lead to eye rubbing and increase oxidative stress in the eye, which may contribute to corneal damage.
• Inflammation. Chronic eye inflammation from conditions like allergies, asthma, or atopic eye disease may contribute to the breakdown of corneal tissue.
• Other conditions: Keratoconus is more common in people with Down syndrome, sleep apnea, Ehlers-Danlos syndrome, etc. The reasons why aren't clear.

Treatment Options for Keratoconus

Treatment for keratoconus depends on the stage, severity, and rate of progression. The overall goal is to prevent keratoconus from getting worse and help you find the best way to see. 

Here are the available treatment options for keratoconus, depending on the severity of your condition:

Mild to Moderate Keratoconus

In the early stages of keratoconus, many people can achieve excellent vision with soft contact lenses or eyeglasses. However, as the condition progresses, glasses and contacts may no longer work. 

Another method of slowing the progression of keratoconus is corneal collagen cross-linking (CXL). This is a minimally invasive procedure that involves the following steps:

1. The doctor numbs your eye with special drops before removing part of your cornea’s outer layer.
2. They’ll administer vitamin B (riboflavin) drops into your eye for 30 minutes or more. 
3. The doctor shines an ultraviolet light onto your eye for 30 minutes while they keep adding more drops.

CXL works by reinforcing collagen bonds in the cornea, making them stiffer and stopping them from bulging outward. Although CXL can slow the progression of the disease, it cannot reverse keratoconus or improve vision.

Intermediate and Advanced Keratoconus

When eyeglasses and soft lenses are no longer effective, your doctor may recommend special contact lenses to improve your vision, these include:

• Rigid gas permeable contact lenses. Rigid contact lenses don’t conform to the cornea’s shape, allowing them to correct visual distortions caused by a cone-shaped cornea.
• Piggyback lenses. These consist of a hard contact lens on top of a soft lens for comfort and optical clarity.
• Hybrid lenses. These lenses have a hard middle and soft edges for comfort.
• Scleral lenses. These rest on the white part of the eye (sclera) instead of directly on the cornea. They’re usually used for severely misshapen corneas.
• PROSE contact lenses. PROSE (prosthetic replacement of the ocular surface ecosystem) is a prosthetic device. It’s often a last resort before surgery.

Intrastromal corneal ring segments (Intacs®) may also be used to manage keratoconus. These are plastic, crescent-shaped rings that flatten the corneal surface.

Intacs help re-focus light onto the retina for clearer vision. Your doctor may combine it with corneal collagen cross-linking to further slow the progression of keratoconus.

Lastly, if other treatments prove ineffective, your doctor may recommend corneal transplant surgery. This involves removing the corneal tissue and replacing it with a donor cornea.

How is Keratoconus Diagnosed?

Keratoconus is diagnosed through a comprehensive eye exam conducted by a licensed ophthalmologist.

These are the general steps of a diagnosis:

1. During the exam, the doctor will examine the physical appearance of the eye to check for a cone-shaped cornea. 
2. They’ll use a slit-lamp microscope to check for corneal thinning and use corneal topography to determine the cornea’s health.
3. They’ll test for visual acuity.
4. Your doctor will combine the results of your symptoms to confirm the diagnosis.

From here, you’ll need to work together with your doctor to find ways to preserve your vision and corneal health.

Remember, early detection and intervention are crucial in managing this condition effectively. If you suspect you or a loved one may have keratoconus, don't hesitate to consult an eye specialist for a comprehensive evaluation.