Keratoconus – Diagnosis, Treatment, & Prevention

Keratoconus (ker-uh-toe-KOH-nus)

Keratoconus is a serious eye condition where the cornea, the dome-shaped surface of your eye, begins to thin and gradually bulges outward, like a cone. 

It often results in astigmatism, nearsightedness, distorted or hazy vision and potentially legal blindness. 

Treatment options vary depending on the severity of the disease. It can be as basic as prescribing special glasses or contact lenses, to more advanced treatments like corneal crosslinking or a full cornea transplant. 

Improving keratoconus vision requires patience and persistence so it’s important you have the right eye care team in place to help you manage this disease and improve your sight.

Let's explore Keratoconus a little deeper to help you understand why people get it and what we can do to treat it. 

What Is Keratoconus?

Keratoconus is when the cornea, the clear dome in the front of your eye, starts to grow outwards with a steep tip so it looks like a little cone. As the cornea bulges outwards, it causes blurry vision and sensitivity to light and glare. 

Keratoconus commonly appears in late adolescence, but it can also begin at a later stage, particularly in your 20s or early 30s.

Severe keratoconus can result in corneal hydrops, a rare complication that occurs when the back membrane of the cornea splits, causing eye fluids to flow unnaturally into your cornea. This might result in pain, swelling, cloudiness, and even vision loss if not treated.

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Why Do People Get Keratoconus?

The specific cause of keratoconus is currently unknown. However, the weakening of corneal tissue that leads to keratoconus could be caused by an enzyme imbalance within the cornea.

The cornea becomes more vulnerable to oxidative damage from free radicals as a result of this imbalance, weakening and bulging forward. Here are some other factors that are often linked with the condition.

• Genetics: Keratoconus may be hereditary. Having a family history of Keratoconus gives you a higher chance of developing the disease. *For parents living with keratoconus, we strongly recommend having your children's eyes checked for indications around the age of ten.
• Underlying Conditions: An underlying autoimmune condition in the body itself that's leading to weaker corneas could be another reason. A side effect of this altered autoimmune state is allergies, leading to dry skin and itchy eyes, which causes people to rub their eyes more.‍
• Excessive Eye Rubbing: Rubbing your eyes excessively can wear down the cornea over time and can also speed up the progression of keratoconus if you already have it.‍
• Inflammation: Allergies, asthma, and atopic eye disease can cause inflammation in the cornea, which in turn can break down the tissue. Keratoconus may develop as a result. ‍
• Improper Use of Contact Lens: A history of poorly fitted contact lenses and chronic eye discomfort may be linked to keratoconus. This makes it important to learn more about contact lens irritation and take measures to avoid it. 

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How Is It Diagnosed?

Diagnosis involves measuring the shape of the cornea. This is called Corneal topography, and is essentially imaging of your cornea to map its curve. 

It is currently the most accurate way to diagnose early keratoconus and follow its progression. 

What Are The Treatment Options?

Eyeglasses or soft contact lenses are often recommended for the mildest form of keratoconus. However, alternate measures like Corneal Crosslinking may be required to prevent the condition from worsening as the cornea becomes more irregular in shape. 

The following are some of the treatments for progressive keratoconus:

Corneal Crosslinking

The current favoured technique to treat keratoconus is Corneal Collagen Crosslinking. This is where drops containing riboflavin (vitamin B2) are instilled into the cornea to reinforce the corneal tissue and prevent it from degrading over time.

If you catch the disease early on, you’re able to lock the cornea in the state in which you found it. However, if you find it too late,  cross-linking will be less effective and you'll likely need a corneal transplant.

Corneal crosslinking may reduce the requirement for corneal transplants in keratoconus patients dramatically. It's also being looked into as a technique to cure or avoid issues after LASIK or other vision correction procedures.

Contact Lenses

Fitting contact lenses on a keratoconus eye can be difficult and time-consuming. Return appointments to your eye doctor are likely, especially if your keratoconus progresses. 

Contact lenses can effectively help correct vision in many cases. Here are the different kinds of contact lenses that your eye doctor may consider.

• Custom Soft lenses: Custom soft contact lenses are specifically developed to address mild-to-moderate keratoconus. They're wider in diameter than conventional soft lenses for more stability on the affected eye. 
• Rigid Gas Permeable(RGP) lenses: When soft contact lenses aren't working to control keratoconus, gas permeable contact lenses are usually the best option. RGP lenses can help mask the irregularities in the corneal shape and are able to correct most corneal astigmatism.
• Hybrid Lenses: Hybrid contact lenses have a hard centre that is highly oxygen-permeable and a soft peripheral "skirt." These lenses were created with keratoconus in mind and the central GP zone arches over the cone-shaped cornea for added comfort. Hybrid lenses combine the clarity of a GP contact lens with the comfort of soft lenses. 
• Prosthetic Scleral Lenses: Patients with severe keratoconus often require a scleral lens, designed to manage very irregular shape changes. Instead of resting on the cornea like traditional contact lenses do, scleral lenses sit on the white part of the eye (sclera) and vault over the cornea without touching it. 
  

Intacs

Intacs are used when a person with keratoconus can no longer achieve functional vision with contact lenses or eyeglasses. These clear, arc-shaped “corneal rings” are surgically implanted into the cornea to reshape the eye's front surface for improved vision, or to make it easier to fit a patient with contact lenses.

The implants have the added benefit of being replaceable and detachable. It takes around 10 minutes to complete the surgery.

Corneal Transplant

A cornea transplant, also known as penetrating keratoplasty, is the only effective therapeutic option in some cases of severe keratoconus. After a cornea transplant, your eyesight may take many months to stabilize, and you will most likely need eyeglasses or contact lenses to see effectively.

It is a relatively safe surgery with an over 90% success rate. However, after a transplant, there is also the danger of infection and graft rejection. Owing to these risks and factors, a cornea transplant is usually only suggested if all previous keratoconus treatments have failed.

How Can We Prevent Keratoconus?

Unfortunately, there is not a whole lot we can do to prevent Keratoconus.

You might be able to lower the risk of developing keratoconus by following the tips below.

• Use sunglasses to protect your eyes from UV rays.
• Ensure that your contact lenses are comfortable.
• Seek treatment for any eye allergies or other ailments.
• Avoid rubbing your eyes.

The Government Supports People With Signs of Keratoconus

Good news for those who catch keratoconus in the early years.  

In BC, if you're under 25 and you have any signs of keratoconus, you're automatically approved for cross-linking. If you're over 25, the risk of it progressing is fairly low, so cross-linking procedures tend to be less common. 

You'll need approval from the B.C. government to get it done. The people in the 25 to 30 year-old range tend to be left frustrated because there's still progression within that specific age group, but the government won't automatically approve it. 

We need to show that there is quite a significant amount of change, and usually at 25 to 30, they'll lose quite a bit of their vision before the government will approve the surgery.

Summary

Keratoconus is a condition not to be taken lightly. 

The most important thing you can do to keep your condition from worsening is to follow the advice your eye doctor gives you regarding best treatment options and follow-up care. 

If you think you or someone you know is showing signs of keratoconus, you should contact your local eye doctor and have an examination done.

And remember the Sigma Eyecare team is here to help. Reach out today to ask us a question or make a booking online.

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