What is Keratoconus? Symptoms, Causes, & Treatment

Keratoconus is a progressive eye condition where your cornea gradually thins and bulges outward into a cone-like shape. Think of your cornea as the clear, dome-shaped front surface of your eye that helps focus light for clear vision.

This gradual change in shape affects how light enters your eye, leading to blurred and distorted vision that worsens over time. While keratoconus might sound scary, understanding what's happening and knowing your treatment options can help you feel more confident about managing this condition.

What is keratoconus?

Keratoconus occurs when the normally round, dome-shaped cornea weakens and begins to bulge forward. Your cornea is made up of tiny fibers of protein called collagen, and when these fibers weaken, the cornea can't maintain its proper shape.

The condition typically affects both eyes, though one eye is usually more severely affected than the other. It most commonly develops during your teens or twenties and can progress for 10 to 20 years before stabilizing.

The good news is that keratoconus rarely causes complete blindness. With proper treatment and monitoring, most people maintain functional vision throughout their lives.

What are the symptoms of keratoconus?

The early signs of keratoconus can be subtle and may feel like you just need a new glasses prescription. Here's what you might notice as the condition develops:

Early symptoms often include:

• Slight blurring of vision that glasses don't seem to fully correct
• Increased sensitivity to bright lights and glare
• Eye strain and headaches, especially after reading or computer work
• Frequent changes in your eyeglass prescription

As keratoconus progresses, you may experience:

• Significantly distorted vision, where straight lines appear wavy or bent
• Multiple images or "ghosting" when looking at objects
• Difficulty driving at night due to glare and halos around lights
• Sudden worsening of vision in one eye
• Eye rubbing that provides temporary relief but may worsen the condition

These symptoms develop gradually, which is why keratoconus is sometimes missed in routine eye exams during its early stages. If you're experiencing any combination of these symptoms, it's worth discussing them with your eye care provider.

What are the types of keratoconus?

Keratoconus is classified based on how severe the corneal changes are and where they occur. Understanding these classifications helps your doctor determine the best treatment approach for your specific situation.

By severity, keratoconus is staged as:

• Mild keratoconus: Slight corneal steepening with minimal vision changes
• Moderate keratoconus: More pronounced corneal distortion affecting daily activities
• Severe keratoconus: Significant corneal thinning and scarring with major vision impairment

By location, keratoconus can be:

• Central keratoconus: The cone develops in the center of your cornea
• Paracentral keratoconus: The cone forms slightly off-center
• Peripheral keratoconus: Less common type where changes occur toward the edge of the cornea

Your eye doctor will use specialized equipment to measure these changes precisely. This staging helps predict how your condition might progress and guides treatment decisions.

What causes keratoconus?

The exact cause of keratoconus isn't fully understood, but researchers believe it results from a combination of genetic, environmental, and behavioral factors. Your cornea's structure depends on a delicate balance of proteins and enzymes, and when this balance is disrupted, weakening can occur.

Genetic factors play a significant role:

• About 1 in 10 people with keratoconus have a family member with the condition
• Certain genetic variations affect collagen production in the cornea
• Having parents or siblings with keratoconus increases your risk

Environmental and lifestyle factors may contribute:

• Chronic eye rubbing, especially vigorous rubbing over many years
• Poorly fitted contact lenses that cause repeated eye irritation
• Chronic eye allergies that lead to frequent rubbing and inflammation
• Excessive UV light exposure without proper eye protection

Associated medical conditions include:

• Down syndrome
• Ehlers-Danlos syndrome
• Marfan syndrome
• Severe atopic dermatitis (eczema)

While you can't control genetic factors, understanding these connections helps explain why some people develop keratoconus while others don't. The important thing is early detection and proper management once it's identified.

When to see a doctor for keratoconus?

You should schedule an eye exam if you're experiencing vision changes that interfere with your daily activities. Early detection of keratoconus can make a significant difference in managing the condition effectively.

Schedule an appointment if you notice:

• Vision that seems blurry or distorted despite wearing current glasses or contacts
• Increasing sensitivity to light that affects your comfort
• Frequent headaches or eye strain during normal activities
• Difficulty seeing clearly for driving, reading, or work tasks

Seek prompt medical attention if you experience:

• Sudden, significant worsening of vision in one or both eyes
• Severe eye pain accompanied by vision changes
• Sudden onset of intense light sensitivity
• Any trauma to the eye followed by vision problems

If you have a family history of keratoconus, mention this to your eye care provider during routine exams. They can perform specialized tests to monitor for early signs even before symptoms develop.

What are the risk factors for keratoconus?

Several factors can increase your likelihood of developing keratoconus, though having risk factors doesn't guarantee you'll develop the condition. Understanding these factors helps you and your doctor stay vigilant for early signs.

Age and demographics:

• Most commonly develops between ages 10 and 25
• Affects people of all ethnicities, though some populations show higher rates
• Occurs equally in men and women
• Rarely develops after age 40

Family and genetic history:

• Having a parent or sibling with keratoconus increases your risk significantly
• Certain genetic syndromes are associated with higher keratoconus rates
• Family history of other corneal conditions may indicate increased risk

Behavioral and environmental factors:

• Chronic, vigorous eye rubbing over many years
• History of poorly fitted contact lenses
• Severe allergies that cause frequent eye rubbing
• Excessive sun exposure without UV protection

Medical conditions that increase risk:

• Severe asthma or allergies
• Connective tissue disorders
• Sleep apnea (which may increase eye rubbing during sleep)
• Certain autoimmune conditions

While you can't change genetic factors, you can reduce controllable risks by avoiding excessive eye rubbing, managing allergies properly, and protecting your eyes from UV damage.

What are the possible complications of keratoconus?

Most people with keratoconus maintain good functional vision with proper treatment, but it's helpful to understand potential complications so you know what to watch for. Your eye care team will monitor for these issues during regular check-ups.

Common complications include:

• Progressive vision loss that becomes difficult to correct with standard glasses or contacts
• Corneal scarring that can permanently affect vision clarity
• Inability to wear contact lenses comfortably due to corneal irregularity
• Increased risk of eye infections from specialized contact lens wear

Less common but serious complications:

• Acute corneal hydrops, where fluid suddenly enters the cornea causing severe vision loss
• Corneal perforation in very advanced cases (extremely rare)
• Severe corneal scarring requiring corneal transplantation
• Development of other eye conditions due to chronic eye rubbing

Rarely occurring complications:

• Complete corneal breakdown requiring emergency treatment
• Severe dry eye syndrome from contact lens complications
• Chronic eye pain that interferes with daily life
• Development of cataracts at an earlier age than typical

The key to preventing complications is regular monitoring and following your treatment plan. Most complications can be managed effectively when caught early, and severe complications are uncommon with modern treatment approaches.

How can keratoconus be prevented?

While you can't prevent keratoconus entirely, especially if you have genetic risk factors, you can take steps to reduce your risk and slow its progression. These preventive measures focus on protecting your corneas from damage and maintaining overall eye health.

Protect your eyes from damage:

• Avoid rubbing your eyes, especially vigorously or frequently
• Wear sunglasses with UV protection when outdoors
• Use protective eyewear during sports or activities with eye injury risk
• Ensure contact lenses fit properly and replace them as directed

Manage underlying conditions:

• Treat allergies effectively to reduce the urge to rub your eyes
• Use artificial tears if you have dry eyes
• Address sleep issues that might increase nighttime eye rubbing
• Follow treatment plans for any connective tissue disorders

Maintain regular eye care:

• Schedule comprehensive eye exams, especially if you have family history
• Report vision changes promptly to your eye care provider
• Follow up as recommended if you're at higher risk
• Learn proper eye hygiene and contact lens care

If you already have keratoconus, these same practices can help slow its progression. The most important preventive measure is avoiding eye rubbing, as this mechanical stress can accelerate corneal weakening.

How is keratoconus diagnosed?

Diagnosing keratoconus involves several specialized tests that measure the shape, thickness, and health of your cornea. Your eye doctor will combine these test results with your symptoms and medical history to make an accurate diagnosis.

Initial examination includes:

• Visual acuity testing to measure how well you see at various distances
• Refraction testing to determine your current glasses prescription
• Slit-lamp examination to look at your cornea under magnification
• Keratometry to measure the curvature of your cornea's front surface

Specialized diagnostic tests:

• Corneal topography, which creates a detailed map of your cornea's surface
• Corneal pachymetry to measure corneal thickness at multiple points
• Optical coherence tomography (OCT) for detailed corneal imaging
• Wavefront analysis to measure how light travels through your eye

Advanced testing when needed:

• Corneal biomechanical testing to assess corneal strength
• Genetic testing if family history suggests hereditary factors
• Tear film analysis if dry eye symptoms are present
• Allergy testing if chronic eye rubbing is suspected

These tests are typically painless and provide your doctor with precise measurements to stage your keratoconus and plan appropriate treatment. Early detection through these advanced testing methods often leads to better long-term outcomes.

What is the treatment for keratoconus?

Keratoconus treatment depends on the severity of your condition and how it affects your daily life. The goal is to provide you with the clearest, most comfortable vision possible while preventing further progression of the condition.

Early-stage treatments:

• Eyeglasses with updated prescriptions for mild vision changes
• Soft contact lenses designed for irregular corneas
• Rigid gas permeable (RGP) contact lenses that create a smooth surface over the irregular cornea
• Hybrid contact lenses combining rigid centers with soft edges for comfort

Progressive keratoconus treatments:

• Corneal cross-linking (CXL) to strengthen corneal tissue and slow progression
• Intacs corneal ring segments inserted to reshape the cornea
• Specialty contact lenses like scleral lenses that vault over the cornea
• Combination treatments using multiple approaches

Advanced treatment options:

• Corneal transplantation for severe cases unresponsive to other treatments
• Deep anterior lamellar keratoplasty (DALK) preserving your own corneal back layer
• Penetrating keratoplasty (full-thickness corneal transplant) for severe scarring
• Artificial cornea implants in rare cases where transplants aren't suitable

Your treatment plan will be tailored to your specific needs and may evolve as your condition changes. Most people achieve good functional vision with non-surgical treatments, and surgical options are reserved for more advanced cases.

How to manage keratoconus at home?

Managing keratoconus at home involves daily habits that protect your eyes and support your treatment plan. These self-care measures can help slow progression and improve your comfort with the condition.

Daily eye care practices:

• Resist the urge to rub your eyes, even when they feel itchy or irritated
• Use artificial tears as recommended to keep eyes moist and comfortable
• Clean and care for contact lenses exactly as prescribed
• Wear sunglasses outdoors to protect against UV damage and reduce glare

Managing symptoms and discomfort:

• Use cool compresses for eye irritation instead of rubbing
• Take frequent breaks from computer work or reading to reduce eye strain
• Adjust lighting in your home and workspace to minimize glare
• Consider using lubricating eye drops before and after contact lens wear

Lifestyle adjustments:

• Treat underlying allergies to reduce eye itching and the urge to rub
• Use a humidifier if you live in a dry climate
• Avoid smoky or dusty environments when possible
• Get adequate sleep to reduce eye strain and fatigue

Monitoring your condition:

• Keep track of vision changes and report them to your eye doctor
• Note any new symptoms or discomfort patterns
• Maintain a schedule for regular eye exams and follow-up appointments
• Stay informed about your treatment options and ask questions

Remember that home management works best when combined with professional medical care. These practices support your treatment but don't replace regular monitoring by your eye care team.

How should you prepare for your doctor appointment?

Preparing for your keratoconus appointment helps ensure you get the most from your visit and that your doctor has all the information needed to provide the best care. A little preparation can make your appointment more efficient and productive.

Gather your medical information:

• Bring your current glasses and contact lenses, even if they're not working well
• List all medications you're taking, including eye drops and supplements
• Note any family history of eye conditions, especially keratoconus
• Bring previous eye exam records if you're seeing a new doctor

Track your symptoms:

• Write down specific vision problems you've noticed and when they occur
• Note any activities that are becoming difficult due to vision changes
• Record any eye discomfort, sensitivity, or pain you're experiencing
• Mention any habits like eye rubbing or specific triggers for symptoms

Prepare questions to ask:

• What stage is my keratoconus and what does that mean for my future vision?
• What treatment options are available for my specific situation?
• How often should I have follow-up appointments?
• Are there activities I should avoid or modify?
• What warning signs should prompt me to call your office?

Plan for your appointment:

• Arrange transportation if your eyes will be dilated
• Bring sunglasses for after the exam
• Allow extra time for specialized testing
• Consider bringing a family member to help remember information

Your eye care provider wants to help you maintain the best possible vision, so don't hesitate to ask questions or express concerns during your visit.

What's the key takeaway about keratoconus?

Keratoconus is a manageable condition that rarely leads to blindness when properly treated and monitored. While receiving this diagnosis might feel overwhelming, understanding that effective treatments exist and that most people maintain good functional vision can provide reassurance.

The most important factor in managing keratoconus successfully is early detection and consistent follow-up care. Modern treatments can slow or stop progression, and various vision correction options can help you maintain an active, fulfilling life.

Remember that keratoconus affects everyone differently, and your treatment plan will be tailored to your specific needs and lifestyle. Working closely with your eye care team, following your treatment plan, and avoiding eye rubbing are the keys to the best possible outcomes.

Stay informed about your condition, but don't let it define your limitations. Many people with keratoconus continue to drive, work, play sports, and enjoy all their usual activities with appropriate vision correction and care.