What is Keratoconus

Introduction

Keratoconus is a progressive eye condition that affects the cornea—the clear, dome-shaped front surface of the eye responsible for focusing light. Instead of maintaining its normal rounded shape, the cornea gradually becomes thin and bulges outward into a cone-like structure. This distortion leads to blurry vision, light sensitivity, and difficulty seeing clearly, especially at night. Although keratoconus can sound intimidating, early diagnosis and modern treatments can significantly protect vision and improve quality of life.

Understanding What is Keratoconus

The cornea works like a natural lens, helping focus light onto the retina. In keratoconus, the internal structure of the cornea weakens. As a result, it becomes thinner over time. This thinning allows the cornea to protrude forward, forming a cone-like shape instead of a smooth curve. When the cornea loses its regular shape, light entering the eye becomes scattered. This leads to visual disturbances such as distorted images, increased glare, and double or ghost vision. Keratoconus typically starts in the teenage years or early adulthood and progresses slowly over several years, although the rate of progression varies from person to person. Some may experience rapid worsening, while others have mild and stable symptoms for a long time.

What Causes Keratoconus?

The exact reason why keratoconus develops is still not fully understood. However, several contributing factors have been identified:

1. Genetics :- Keratoconus tends to run in families. If a parent or sibling has it, the chances increase. Research shows that genetic mutations affecting collagen and corneal strength can play a role.
2. Eye Rubbing :- Frequent or aggressive eye rubbing, especially due to allergies, is one of the strongest risk factors. Continuous pressure on the cornea can weaken its structure.
3. Allergies & Atopic Conditions :- Conditions like asthma, eczema, and allergic conjunctivitis are associated with keratoconus, mostly due to chronic inflammation and increased eye rubbing.
4. Connective Tissue Disorders :- Marfan syndrome, Ehlers-Danlos syndrome, and other connective tissue diseases may increase the likelihood of keratoconus.
5. Oxidative Stress :- The cornea is constantly exposed to UV rays and environmental irritants. Excess free radicals may weaken collagen fibers in the cornea, making it more prone to thinning.

Although these factors contribute, anyone can develop keratoconus even without a family history or allergies.

Common Symptoms of Keratoconus

The symptoms depend on how advanced the condition is. In the early stages, signs may be mild and often mistaken for simple vision issues. Over time, they become more noticeable.

Typical symptoms include

1. Blurry or distorted vision
2. Increased sensitivity to bright lights
3. Halos or glare around lights
4. Difficulty seeing clearly at night
5. Frequent changes in eyeglass prescriptions
6. Double vision (even with one eye open)
7. Sudden worsening of vision due to corneal swelling

As the cornea becomes more cone-shaped, fitting regular glasses becomes harder, and many patients require specialized contact lenses.

How Keratoconus is Diagnosed

Early detection is crucial. Eye doctors use several advanced tests to detect even the earliest signs of corneal thinning.

1. Corneal Topography :- This is the gold standard for diagnosing keratoconus. It maps the cornea’s surface and detects irregularities long before symptoms appear.
2. Pachymetry :- This test measures corneal thickness. Thinner-than-normal corneas are a key indicator of keratoconus.
3. Slit-Lamp Examination :- The doctor checks for changes in the cornea’s shape, clarity, and structural integrity.
4. Keratometry :- This measures the curvature of the cornea and helps monitor progression.

Regular eye checkups especially for teenagers with frequent prescription changes can help catch keratoconus early.

Stages of Keratoconus

Keratoconus is often described in three stages

1. Early Stage :- Mild blurring, slight corneal steepening, and frequent changes in eyeglass power.
2. Moderate Stage :- Increasing distortion, need for rigid lenses, and more noticeable irregularities.
3. Advanced Stage :- Significant thinning, scarring, and inability to use contact lenses comfortably. Vision may be severely affected.

Not all patients progress to severe stages, especially if treated early.

Treatment Options for Keratoconus

Treatment depends on the stage of the condition and how quickly it is progressing. Thankfully, modern technology has made managing keratoconus highly effective.

1. Eyeglasses & Soft Contact Lenses :- Useful in early stages. They help correct mild refractive errors.
2. Rigid Gas Permeable (RGP) Lenses :- These hard lenses provide a smooth optical surface and are commonly used in moderate keratoconus.
3. Scleral Lenses :- Larger lenses that rest on the sclera (white part of the eye). They are comfortable and excellent for advanced cases.
4. Corneal Cross-Linking (CXL) :- This is the most crucial treatment to stop keratoconus from getting worse. It strengthens collagen fibers in the cornea using UV light and riboflavin (vitamin B2). CXL does not reverse keratoconus, but it prevents future progression.
5. Intracorneal Ring Segments (ICRS) :- Small plastic rings are inserted into the cornea to flatten its shape and improve vision.
6. Corneal Transplant :- Used only in severe or scarred corneas. Either a partial-thickness (DALK) or full-thickness transplant may be performed.

Early treatment, especially cross-linking, can often prevent the need for transplant surgery.

Living with Keratoconus

With proper care, regular follow-ups, and timely treatment, most people with keratoconus lead normal lives with good vision. Here are helpful tips

1. Avoid rubbing your eyes
2. Manage allergies to reduce irritation
3. Wear sunglasses outdoors
4. Follow up regularly with your eye specialist
5. Use prescribed contact lenses properly
   

Keratoconus can’t be cured permanently, but it can be successfully managed with modern medical options.

Conclusion

Keratoconus is a progressive eye condition that causes the cornea to become thin and cone-shaped, leading to distorted vision. While the exact cause is uncertain, genetic factors, eye rubbing, allergies, and connective tissue disorders play important roles. Early symptoms may be subtle, but regular eye checkups allow timely detection.