Keratoconus is an eye condition in which the cornea, the clear front surface of the eye, gradually thins and bulges into a cone-like shape. This irregular shape can cause blurry vision, distorted vision, light sensitivity, glare, and frequent prescription changes.
Keratoconus is not extremely common, it affects approximately one in two thousand patients. However it is serious enough to affect vision when it is not detected and managed early. It can permanently impair vision if not detected and addressed in its early stages.
What is Keratoconus?
Keratoconus (keh-rah-toh-KOH-nus) is a progressive eye condition where the cornea, the clear, dome-shaped front part of the eye, thins and bulges outward into a cone shape. When light enters through this irregular shape, it does not focus properly, which can cause blurry, distorted vision.
As the condition progresses, the cone shape may become more noticeable, making it harder to see clearly. Keratoconus is considered a progressive corneal disease because it changes the shape and strength of the cornea over time. This eye condition often begins in the late teens to 30s. About 1 in 10 people with keratoconus have a family member who also has the condition.
Symptoms of Keratoconus
Keratoconus symptoms vary from person to person, but recognizing early signs is essential.
The issue often starts subtly and may be mistaken for nearsightedness or astigmatism. Symptoms may progress over time and begin to affect daily activities, such as reading, driving, or working on a screen.
Patient symptoms can include:
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The eye feels irritated or gritty, with obvious signs of redness.
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Objects may look blurry or distorted, even with glasses or contact lenses.
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Because keratoconus can progress, your prescription may change more often than expected.
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Bright light may cause discomfort or glare.
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A single object may appear doubled, shadowed, or overlapped, even when only one eye is open.
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Patients often struggle to see clearly in low-light conditions.
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Bright lights may have glowing rings or halos around them, especially at night.
Patients may also notice these symptoms in advanced stages:
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Corneal scarring can occur in more advanced keratoconus. This causes blurry vision that does not clear up.
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Continuous eye strain can lead to headaches after the prolonged effort to focus, creating a constant feeling of eye fatigue.
Sudden clouding or fogging of vision, or a rapid change in vision should be evaluated promptly by your optometrist.
What Causes Keratoconus?
The exact cause of keratoconus is not fully understood. However, research suggests that it is due to a combination of environmental, genetic, and biochemical factors. Around 1 in 10 people who have this condition have a family member with keratoconus.
The following are contributing factors.
Eye Rubbing
Chronic eye rubbing is a known risk factor and may contribute to keratoconus progression, especially in people with allergies or frequent eye irritation. This is especially true for individuals with conditions such as eczema or other allergies.
Genetics
Family history can increase risk, so it is important to mention keratoconus in your family during an eye exam. This makes family history important to discuss during an eye exam.
Health Conditions Linked to Keratoconus
Individuals with the following issues are more likely to develop keratoconus:
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Downs syndrome
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Asthma or other chronic allergies
Oxidative Stress
Some research has looked at oxidative stress as a possible factor in keratoconus, but this is not something patients can diagnose or manage on their own.
When to See a Your Optometrist
If blurry vision doesn't go away even with glasses, or if your prescription is changing rapidly, you should consult an optometrist. Early detection can help protect vision and provide guidance to the appropriate treatment plan.
Keratoconus Diagnosis
During an eye exam, these diagnostic methods may be used:
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Keratometry to determine the curvature of the cornea.
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Pachymetry to measure the corneal thickness.
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Corneal topography creates a detailed map of the cornea’s surface shape, highlighting abnormalities.
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Slit-lamp examination to closely inspect the cornea for signs of scarring or thinning.
Keratoconus Treatment Options
Treatment for keratoconus depends on severity and whether the condition is still progressing. The following are some proven ways to improve your condition, the effectiveness of which depends on what stage of the disease you are in.
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Soft Contact Lenses or Eyeglasses
Soft toric lenses or regular glasses can correct mild nearsightedness and astigmatism caused by keratoconus.
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Rigid Gas Permeable (RGP) Contact Lenses
Rigid gas permeable lenses can create a smoother focusing surface over the irregular cornea to improve vision.
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Scleral Lenses
For patients who cannot tolerate RGP lenses, scleral lenses are a viable alternative. They may provide better comfort and clearer vision for some patients.
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Corneal Cross-Linking (CXL)
CXL is an FDA-approved treatment that stabilizes the corneal tissue by using UV light and riboflavin (vitamin B2). It then creates new collagen bonds. Although corneal cross-linking does not reverse keratoconus, it may slow or stop progression in appropriate patients.
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Intacs
Intrastromal corneal ring segments, sometimes called Intacs, may be considered for some patients with mild to moderate keratoconus. Your optometrist can refer you to a corneal specialist if this option may be appropriate for you.
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Corneal transplant
A corneal transplant may be considered in severe cases with advanced scarring, thinning, or poor vision that cannot be corrected with specialty contact lenses. Your optometrist can refer you to a corneal specialist if this becomes necessary.
Living With Keratoconus
Feeling overwhelmed after a keratoconus diagnosis is natural. With regular monitoring and the appropriate treatment plan, most people with keratoconus can maintain functional vision. Corneal cross-linking may slow or stop progression in many patients.
Here are some practical tips to manage life with keratoconus:
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Avoid eye rubbing.
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Use protective eyewear during sports or outdoor activities.
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Talk openly with your optometrist about symptoms and treatment options.
Vision Source Rio and Vision Source Heights Can Evaluate Keratoconus Symptoms
Treatment depends on how advanced the condition is and whether it is still progressing. Early keratoconus may be managed with glasses or soft contact lenses.
More advanced cases may require rigid gas permeable or scleral lenses. If keratoconus is progressing, your optometrist may refer you to a corneal specialist to discuss corneal cross-linking or other procedures.
Vision Source Rio and Vision Source Heights provide comprehensive eye exams, advanced diagnostic imaging, and personalized guidance for keratoconus symptoms.
Schedule an eye exam with your optometrist.
