Keratoconus
Overview
Keratoconus is an eye condition where the cornea, the clear front part of your eye, gets thinner and bulges outward, like a cone. This change in shape makes your vision blurry and sometimes distorted. You might also notice more sensitivity to light and glare. Usually, both eyes are affected, but one eye may be more affected than the other. This condition typically starts in people between their late teens and early 30s, and its progression can take 10 years or more.
Early on, glasses or soft contact lenses may be enough to correct the vision problems. As the condition gets worse, you might need special rigid contact lenses (sometimes called gas permeable lenses), or even scleral lenses. If the keratoconus progresses significantly, a cornea transplant might become necessary.
A treatment called corneal collagen cross-linking (CXL) can sometimes slow or stop the progression of keratoconus. This could help avoid the need for a transplant in the future. CXL is sometimes offered along with other vision correction options.
Symptoms
Keratoconus symptoms can get different as the condition develops. Common signs include:
- Blurred or distorted vision: Things might look fuzzy or out of shape.
- Sensitivity to light and glare: Bright lights or reflections can be very uncomfortable, especially at night when driving. This can make it harder to see clearly at night.
- Frequent eyeglass changes: You may need to get new prescriptions more often as your eyesight changes.
- Sudden vision problems: Your vision might get worse quickly, or become cloudy. This could be a sign of a problem with the eye's shape, like astigmatism. This could also mean something more serious, like keratoconus.
It's important to see an eye doctor if your vision changes quickly. They can check for signs of keratoconus during regular eye exams, as well as other possible causes of vision problems. An irregular curve in the eye's surface (astigmatism) can also cause blurry vision, but keratoconus is a more serious condition.
When to see a doctor
If your vision is getting worse quickly, see an eye doctor. This could be a sign of astigmatism, a condition where the front surface of your eye isn't perfectly smooth, like a slightly uneven football. During regular eye exams, your doctor will also check for keratoconus, a more serious condition where the cornea (the clear front part of your eye) thins and becomes cone-shaped. Early detection is important for both conditions.
Causes
Keratoconus is a condition where the cornea, the clear front part of the eye, thins and changes shape. Scientists don't fully understand what causes it, but they think a combination of genetics and things in the environment might play a role. If you have keratoconus, there's about a 10% chance one of your parents also has it.
Risk factors
Keratoconus is a condition where the cornea (the clear front part of your eye) thins and becomes cone-shaped. Several things can make you more likely to get it.
One important factor is a family history of keratoconus. If your parents or other close relatives had it, you have a higher chance of developing it yourself.
Another thing that can increase your risk is frequently rubbing your eyes hard. This can put extra stress on your cornea, potentially leading to changes that could cause keratoconus.
Certain health conditions can also raise your risk. These include:
- Inherited eye conditions: Conditions like retinitis pigmentosa, which affects the light-sensitive cells in the eye, can sometimes be linked to keratoconus.
- Genetic disorders: Down syndrome, Ehlers-Danlos syndrome, and Marfan syndrome are genetic conditions that may increase the risk of keratoconus. These conditions can affect the connective tissues throughout the body, potentially impacting the eye as well.
- Allergies: Conditions like hay fever and asthma, while not directly related to the cornea, can sometimes be linked to increased eye rubbing or other factors that might contribute to the development of keratoconus.
Understanding these risk factors can help you talk to your eye doctor about your individual risk and take steps to protect your eyes.
Complications
Sometimes, your cornea (the clear front part of your eye) can swell up quickly, making your vision blurry and causing permanent damage. This happens when the inner layer of your cornea, called Descemet's membrane, gets damaged. This damage lets fluid seep into the cornea, a condition called hydrops. Usually, the swelling goes away on its own, but a scar might develop, which can affect your vision.
A more serious eye condition called keratoconus can also lead to scarring on the cornea, especially in the area where the cornea is bulging outward. This scarring makes vision problems worse. In severe cases, a cornea transplant might be needed.
Diagnosis
To figure out if you have keratoconus, your eye doctor will first ask about your health history and any family history of eye problems. They'll then do an eye exam. Further tests may be needed to precisely understand the shape of your cornea. Here are some common diagnostic tests:
-
Eye Refraction: Your doctor uses special tools to measure how your eyes focus light. You might look through a device with different lenses (called a phoropter) to see which lens gives you the clearest vision. Some doctors use a handheld tool called a retinoscope for the same purpose. This helps determine the correct prescription for glasses or contact lenses.
-
Slit-Lamp Examination: A special light and microscope are used to look closely at the surface of your eye. Your doctor will carefully examine the shape of your cornea and look for any other potential eye issues. This is a standard part of any eye exam, and your doctor will look for any signs of keratoconus.
-
Keratometry: The doctor directs a light onto your cornea and measures how that light reflects. This measurement helps determine the precise curve and shape of your cornea. This is valuable in identifying changes in the cornea's shape.
-
Computerized Corneal Mapping: Specialized photography, such as corneal tomography and topography, takes detailed pictures of your cornea. These pictures are used to create a detailed map of the cornea's shape. Corneal tomography can also measure the thickness of the cornea. This type of testing is often very helpful in detecting early keratoconus, sometimes before it's noticeable with a regular eye exam. These tests provide a comprehensive view of the cornea's structure.
Treatment
Treating Keratoconus: Options for Better Vision
Keratoconus is an eye condition where the cornea, the clear front part of the eye, thins and bulges out, causing blurry or distorted vision. Treatment depends on how severe the condition is and how quickly it's getting worse. The goals of treatment are to slow the progression of the disease and improve vision.
Slowing the Progression:
If the keratoconus is getting worse, a procedure called corneal collagen cross-linking (CXL) might be recommended. This involves putting special eye drops in the cornea and then using ultraviolet light to strengthen the cornea's structure. This can help stop the cornea from bulging further and sometimes even reverse some of the bulging. This can help you avoid needing a cornea transplant later on.
Improving Vision:
How vision is improved depends on the severity of the keratoconus.
-
Early Stages: For mild to moderate keratoconus, eyeglasses or soft contact lenses can often correct the blurry vision. As the cornea changes, you may need to adjust your eyeglass or contact lens prescription more often, especially if the condition stabilizes after CXL.
-
More Advanced Stages: As the disease progresses, other types of contact lenses may be necessary.
- Hard contact lenses: These lenses are often a good option for more advanced cases, offering excellent vision correction. They come in different types, including rigid gas permeable lenses. They might feel uncomfortable at first, but many people adjust. They can be custom-fitted to your cornea.
- Piggyback lenses: If hard lenses are too uncomfortable, a soft contact lens can be worn underneath a hard lens.
- Hybrid lenses: These lenses combine a hard center with a softer outer ring for added comfort.
- Scleral lenses: In very advanced cases with significant corneal changes, scleral lenses are used. These lenses rest on the white part of the eye (sclera) and vault over the cornea, providing a stable fit. This is a good alternative to surgery for many people.
Important Note: If you're using rigid or scleral contact lenses, it's crucial to have them fitted and regularly checked by an eye doctor experienced in keratoconus. Poorly fitting lenses can damage your cornea. Scleral lenses cover the white part of your eye, and a protective layer of saline solution sits between the lens and your eye.
Surgery:
Surgery may be needed if there's significant corneal scarring, thinning, or if you can't achieve good vision with contact lenses or if contact lenses are no longer comfortable. Some surgical options include:
-
Intrastromal Corneal Ring Segments (ICRS): Small rings are inserted into the cornea to flatten it, improving vision and making contact lenses more comfortable. This may be combined with CXL.
-
Cornea Transplant (Keratoplasty): A cornea transplant is often the last resort. In this procedure, a damaged part of your cornea is replaced with healthy tissue from a donor. This surgery has a high success rate, but like any surgery, there are potential complications including rejection, infection, or poor vision outcomes. Astigmatism, a common eye condition, can sometimes be managed by wearing hard contact lenses again after a transplant, which is often more comfortable than after the initial surgery.
It's important to discuss all treatment options with your eye doctor to determine the best approach for your specific case.
Disclaimer: August is a health information platform and its responses don't constitute medical advise. Always consult with a licenced medical professional near you before making any changes.