Keratoconus – Symptoms and Causes

Overview

Keratoconus is an eye disorder. It causes the cornea to thin and bulge into a cone-like shape. This abnormal shape prevents light from focusing properly on the retina, causing vision problems.

This condition typically affects both eyes. However, one eye may experience more severe symptoms than the other. Keratoconus usually begins during the late teenage years or early twenties. It may continue to worsen for about 10 years or more.

Common symptoms include:

• Blurred vision
• Increased sensitivity to light and glare
• Frequent changes in eyeglass prescriptions
• Difficulty seeing at night

Treatment options depend on the severity and progression of the condition:

1. Early Stages: Glasses or soft contact lenses.
2. Moderate Stages: Rigid gas permeable contact lenses or scleral lenses.
3. Advanced stages: Corneal transplant may become necessary.

A treatment called corneal collagen cross-linking has shown promise in stopping or slowing the progression of keratoconus. This procedure strengthens the corneal tissue and may prevent the need for transplant surgery in many patients.

Signs and Symptoms

Keratoconus causes several vision changes that may progress over time:

• Blurry or warped vision
• Light sensitivity and trouble with glare, especially when driving at night
• Frequent eyeglass prescription changes
• Unexpected vision changes or clouding

Vision problems often start slowly but can worsen as the condition advances. Many people notice they need stronger glasses more often than usual.

When You Should Contact an Eye Specialist

Contact your eye doctor right away if you notice your vision getting worse quickly. This rapid change might be caused by astigmatism, which is an irregular curve in your eye.

Eye specialists often check for keratoconus during regular eye exams. Getting checked early can help manage the condition before it causes more serious vision problems.

Causes

Keratoconus develops from a mix of genetic and environmental factors. About 10% of people with this eye condition have a parent who also has it, suggesting a hereditary link.

While the exact triggers remain unknown, family history plays a significant role in determining risk.

Risk Factors

Several factors may raise your chance of developing keratoconus:

• Family history – The condition often runs in families.
• Eye rubbing – Vigorous or frequent rubbing of eyes can increase risk.
• Health conditions – People with certain conditions face higher risk, including:
  • Down syndrome
  • Ehlers-Danlos syndrome
  • Marfan syndrome
  • Retinitis pigmentosa
  • Hay fever and asthma

Complications

Keratoconus can lead to serious eye problems in some cases:

Sudden Corneal Swelling (Hydrops)

• This occurs when the inner corneal lining (Descemet’s membrane) breaks.
• The break allows fluid to enter the cornea, which causes rapid swelling and sudden vision loss.
• Usually, hydrops resolves on its own, but it may leave vision-affecting scars.

Corneal Scarring

Severe keratoconus often leads to scarring, especially at the most prominent part of the cone. This scarring worsens vision problems over time.

When these complications become severe enough to significantly impact vision, corneal transplant surgery might become necessary. Regular eye exams help detect these complications early, potentially preventing permanent vision damage.