Keratoconus Treatment

Keratoconus is a progressive corneal disease that causes corneal thinning and cone-shaped deformation, resulting in distorted vision and loss of visual acuity. Treatment depends on the severity and speed of progression. Below are the available options based on the stage of the disease.

1. Non-Surgical Treatments (Early Stages)

Spectacles, Soft Lenses, or Phakic Intraocular Lenses (ICLs)

Useful in very early stages, when irregular astigmatism is mild.

They do not slow progression, but they do temporarily improve vision.

Rigid Gas Permeable Contact Lenses (RGP)

These are the gold standard for vision correction in moderate keratoconus.

They provide a smooth surface that neutralizes corneal irregularity.

Types:

Conventional RGP lenses: Adapted to the conical shape.

Hybrid lenses: Rigid center with soft edge for greater comfort.

Scleral lenses: Cover the entire cornea and rest on the sclera, ideal for advanced cases.

Nocturnal Orthokeratology (Ortho-K)

Use of special rigid lenses at night to temporarily reshape the cornea.

Limited effect in keratoconus and requires strict supervision.

2. Treatments to Halt Progression (Corneal Crosslinking)

Corneal Crosslinking (CXL)

Goal: To strengthen corneal collagen fibers to halt the progression of keratoconus.

Procedure:

Riboflavin (vitamin B₂) is applied to the cornea.

It is exposed to ultraviolet (UVA) light to create new molecular bonds.

Types:

Epi-on CXL: Less invasive (without removing the epithelium), but less effective in advanced cases.

Epi-off CXL: More effective (the epithelium is removed), requires a longer recovery time.

Efficacy: Successful in >90% of cases to stabilize the disease.

3. Surgical Treatments (Advanced Cases)

Intracorneal Rings (ICRS) in the Treatment of Keratoconus

Intracorneal rings (ICRS), also known as corneal ring segments (Intacs®, Keraring®, Ferrara®, MyoRing®), are medical plastic devices (PMMA or biocompatible materials) that are implanted within the thickness of the cornea to flatten the conical area, improve vision, and delay the need for a corneal transplant.

How Do Intracorneal Rings Work?

Mechanical Effect: The rings redistribute corneal tension forces, flattening the bulging area (cone) and improving the shape of the cornea.

Optical Effect: They reduce irregular astigmatism, which can improve visual acuity and facilitate contact lens wear.

They do not stop the progression of keratoconus, but can be combined with Crosslinking (CXL) for greater stability.

In What Cases Are They Recommended?

✅ Patients with progressive keratoconus who no longer improve with glasses or contact lenses.

✅ Intolerance to rigid lenses due to discomfort or poor fit.

✅ Moderate-stage keratoconus (without central scarring).

✅ Combination with Crosslinking (CXL) to slow progression.

Contraindications:

❌ Excessively thin cornea (<400 µm).

❌ Central corneal scarring.

❌ Very advanced keratoconus (transplant may be a better option).

Expected Results

Improvement of 2-4 lines in visual acuity (in 60-80% of cases).

Reduction of irregular astigmatism (up to 50%).

Delaying or avoiding a corneal transplant.

Can the rings be removed?

Yes, if there is no improvement or there are complications.

The cornea usually returns to its original shape.

Corneal Transplant

Indicated for advanced keratoconus with scarring or lens intolerance.

Types:

Penetrating Keratoplasty (PKP): Complete replacement of the cornea (more common in the past).

Lamellar Keratoplasty (DALK): Replacement of only the affected layers (lower risk of rejection).

Recovery: May take up to 1 year, with the need for postoperative contact lenses.

4. Emerging Alternatives

Topoguided PRK + Crosslinking:

Excimer laser for corneal reshaping along with CXL (in selected cases).

Biosynthetic corneal collagen:

Under investigation for regenerating corneal tissue.

Importance of Avoiding Eye Rubbing in Keratoconus

One of the key factors in the development and progression of keratoconus is constant eye rubbing, especially in patients with eye allergies (such as allergic conjunctivitis).

Why does rubbing worsen keratoconus?

It weakens the cornea: The mechanical pressure from repetitive rubbing thins and deforms the corneal tissue, accelerating the formation of the "cone."

It increases inflammation: It releases enzymes (such as collagenases) that degrade corneal collagen.

It reduces the effectiveness of treatments: Even with crosslinking (CXL) or intracorneal rings, if the patient continues rubbing, the disease can progress.

Allergy Management and Habits to Slow Progression

1. Control of Ocular Allergies

Topical antihistamines (drops such as olopatadine or ketotifen) to reduce itching.

Preservative-free lubricants (cold artificial tears) to relieve irritation.

Avoid allergens (mites, pollen, pets) and wear sunglasses outdoors.

2. Patient Education

Do not rub your eyes! It is crucial to replace rubbing with alternatives:

Apply cold compresses to soothe itching.

Use lubricating drops instead of scratching.

In children/adolescents (at-risk group), monitor nighttime habits (sleeping with hands near the face).

3. Combined Treatments with CXL

If keratoconus is already advanced due to rubbing, corneal crosslinking (CXL) can stabilize it, but only if the patient stops rubbing. Otherwise, the cornea will continue to deteriorate.

Prognosis: Depends on the patient.

If the rubbing is eliminated:

Treatments (lenses, CXL, rings) have a high probability of success.

If the rubbing persists:

The disease will progress even with surgery, possibly leading to a corneal transplant.

Keratoconus Diagnosis: The Importance of Corneal Topography

Early and accurate diagnosis of keratoconus is essential to prevent its progression. The most important tool for detecting and monitoring it is corneal topography, a noninvasive study that analyzes the shape and curvature of the cornea in detail.

Why is corneal topography essential?

It detects keratoconus in its early stages (even before symptoms appear).

It maps irregularities in the corneal curvature that are not visible in a conventional exam.

It identifies characteristic patterns such as:

Inferior-superior asymmetry (the cornea is more curved in the lower area).

Irregular astigmatism.

Areas of corneal thinning.

It classifies the severity of keratoconus (mild, moderate, advanced) to determine the appropriate treatment.

It monitors progression with comparative periodic exams (every 6-12 months).

It guides specialized treatments, such as the fitting of rigid contact lenses or surgical planning (intracorneal rings, crosslinking).

Other Complementary Studies

Although corneal topography is the gold standard, in some cases it is combined with:

Corneal pachymetry: Measures corneal thickness (keratoconus often thins the cornea).

Corneal tomography (such as Pentacam): Provides a more detailed 3D analysis.

Corneal biomechanics (Corvis ST, ORA): Evaluates corneal resistance.

When should you have a corneal topography?

If you have:

High or rapidly increasing astigmatism.

Frequent changes in lens prescription.

Family history of keratoconus.

Eye allergies with constant rubbing.