Keratoconus – Diagnosis and Treatment
Diagnosis
A doctor can find keratoconus early through a thorough eye examination. The doctor starts by asking about your personal and family medical history, focusing on vision problems, allergies, or frequent eye rubbing.
Key signs and symptoms that may mean you have keratoconus include:
- Blurred or distorted vision
- Difficulty seeing at night
- Sudden changes in vision
- Increased nearsightedness or astigmatism
- Eye irritation
- Sensitivity to light
Eye care professionals use several tests to check for these problems.
| Test Name | Purpose |
|---|---|
| Eye Refraction | Measures vision strength using a phoropter or retinoscope to find the best lens correction. |
| Slit-Lamp Exam | Uses a bright light and microscope to look for corneal thinning or cone-like shape. |
| Keratometry | Shines a circle of light onto the cornea to measure its basic curve and shape. |
| Corneal Mapping | Uses corneal topography or tomography to make a detailed map of the cornea and its thickness. |
Corneal mapping helps by showing small changes in the cornea early, even before a doctor can see them under the microscope.
Regular eye exams help people with a family history of keratoconus get diagnosed early. Noticing symptoms like vision changes, sensitivity to light, or discomfort should prompt testing.
Treatment
Glasses and Contact Lens Choices
People with keratoconus often start vision correction with eyeglasses or soft contact lenses. These options work well in mild or early stages but may need frequent prescription changes as the cornea changes shape.
When glasses or soft contacts stop working, doctors recommend other types of lenses.
| Lens Type | Description | Best For |
|---|---|---|
| Eyeglasses | Simple prescription glasses | Early-stage keratoconus |
| Soft Contact Lenses | Soft material, comfortable for daily wear | Mild vision issues |
| Rigid Gas Permeable (RGP) | Hard lenses offering clear vision by covering irregular corneas | Moderate to advanced cases |
| Piggyback Lenses | RGP lens worn over a soft lens for extra comfort | Those who find RGPs uncomfortable |
| Hybrid Lenses | Rigid center (like RGP) and soft outer ring for better comfort | Those sensitive to hard lenses |
| Scleral Lenses | Large lenses rest on sclera and arch over cornea, filled with saline solution | Severe or irregular corneas |
Eyeglasses and soft contacts offer quick solutions, but they help less as keratoconus gets worse.
Rigid gas permeable lenses provide more stable vision, but they can be uncomfortable at first. Piggyback lenses combine hard and soft lenses for added comfort.
Hybrid lenses have a hard center and a soft edge, making them easier to wear. Scleral lenses rest on the white part of the eye and avoid touching the cornea, which helps when the cornea is very uneven.
Tips:
- Have lenses fitted by a specialist who knows keratoconus.
- Get regular checkups to make sure lenses fit well and do not harm your eyes.
Medical Treatments for Stabilizing the Cornea
Doctors use certain therapies to slow or stop keratoconus from getting worse. One main option is corneal collagen cross-linking.
Corneal Collagen Strengthening
Corneal collagen cross-linking makes the cornea stronger. The doctor applies vitamin B2 (riboflavin) eye drops and shines ultraviolet (UV) light on the cornea. This creates new bonds between collagen fibers, helping the cornea stay stable.
This therapy does not restore lost vision, but it can slow or stop keratoconus from progressing.
| Step | Details |
|---|---|
| Vitamin Drops Applied | Riboflavin drops placed on the cornea |
| UV Light Exposure | The cornea is exposed to UV light to activate the drops. |
| Cross-links Formed | New bonds between collagen fibers stiffen the cornea. |
Benefits:
- Prevents further thinning and bulging.
- Reduces the chance of needing a corneal transplant.
- May help other treatments, like lenses, work better.
Some patients receive both cross-linking and ring implants for better results.
Surgical Procedures for Advanced Cases
People with scarring, severe corneal thinning, or vision loss that lenses or therapies cannot help may need surgery. The main surgical options focus on improving vision and corneal health.
Corneal Ring Implants (Intrastromal Devices)
A surgeon places small plastic or synthetic rings (Intacs) inside the cornea. These rings flatten and reshape the cornea, improving vision and making contact lenses fit more easily.
Doctors often pair this surgery with cross-linking to stabilize the cornea.
Key Points about Corneal Ring Surgery:
- Works best for mild to moderate keratoconus when the cornea is not scarred.
- Offers quick recovery and is often reversible.
Cornea Transplantation
If other treatments do not help or if there is advanced scarring and thinning, a doctor may suggest a cornea transplant (keratoplasty).
Types of Corneal Transplant:
| Type of Transplant | What is Replaced | When Used |
|---|---|---|
| DALK | Front layers of cornea only | Scarring/irregularities, clear endothelium |
| Penetrating Keratoplasty | Entire corneal thickness | Severe cases or damaged endothelium |
- Deep Anterior Lamellar Keratoplasty (DALK): Only the front layers are replaced.
- Penetrating Keratoplasty: The surgeon replaces the full thickness of the cornea.
Cornea transplants usually work well. Risks include graft rejection, infection, or astigmatism, which may need glasses or hard lenses after surgery.
Summary List of Surgical Steps:
- The doctor checks vision and corneal health.
- The best type of transplant is chosen.
- The surgeon replaces damaged tissue with a donor cornea.
- Regular follow-up appointments are needed.
Additional Notes:
Some people need contact lenses after a transplant, but these lenses are often more comfortable on the new cornea.
Doctors use surgery as a last resort for advanced disease.
Getting Ready for Your Visit
Steps You Should Take Beforehand
Prepare for your eye care appointment by making a list of:
- Current symptoms and when they started
- Any big changes or stressors in your life
- Medications, eye drops, vitamins, or supplements you take (include how much and how often)
- Questions you want to ask, especially about causes, testing, treatments, options, and managing other health issues with keratoconus
| Question | Purpose |
|---|---|
| What might be causing my vision changes? | Understand possible diagnoses |
| Are there other reasons for these symptoms? | Consider all possibilities |
| Will I need special tests? | Prepare for next steps |
| Are there treatment choices, and what do you suggest? | Learn about options |
| Can I get information to read at home? | Continue learning after the visit |
If you have a family history of keratoconus or other eye conditions, write that down, as it may help your doctor assess your risk.
What Your Eye Specialist Might Ask
During your visit, the optometrist or ophthalmologist will usually ask about:
Details of Your Visual Symptoms: What type they are, how long you have had them, and how severe they feel.
Pattern of the Symptoms: Are they always there, or do they come and go?
Eye Rubbing Habits: Do you often rub your eyes? This can affect the cornea.
Factors that make symptoms better or worse.
Medical history: Your current and past health conditions.
Family history: Whether your relatives have keratoconus or similar eye problems.
The doctor will review your answers and talk with you about them. This helps the doctor decide which tests or treatments you might need.
