When Do Keratoconus Patients Need a Corneal Transplant?

One of the most serious—and final—treatment options is a corneal transplant.

Figure 1: Side view of a keratoconus patient wearing a scleral contact lens.

Keratoconus is a progressive eye disease that causes the normally round cornea to thin and bulge into a cone-like shape. This irregular shape distorts vision and can significantly impact daily life. While early stages of keratoconus can often be managed with glasses or contact lenses, more advanced cases may require surgical intervention.

But when exactly does it become necessary?

Understanding the Progression of Keratoconus

In the early stages of keratoconus, the cornea remains relatively stable and vision can usually be corrected with glasses or soft contact lenses. As the disease progresses, however, the cornea becomes increasingly misshapen and thin. This can lead to:

• Severe visual distortion (ghosting, halos, multiple images)

• Inability to tolerate contact lenses

• Scarring of the cornea

• Sudden corneal hydrops (swelling from fluid buildup)

Signs That a Corneal Transplant May Be Needed

Corneal transplants are typically considered only after other treatment options have been exhausted. Here are the key signs that a transplant may be necessary:

1. Contact Lens Intolerance

In many keratoconus cases, rigid gas permeable (RGP) or scleral lenses are used to correct vision by masking the irregular corneal shape. However, if patients can no longer tolerate these lenses due to discomfort or poor fit, and if vision cannot be corrected otherwise, a transplant may be the next step.

2. Corneal Scarring

As keratoconus progresses, the cornea may develop scarring, particularly after episodes of corneal hydrops or long-term mechanical stress from poorly fitting lenses. Scarring can cause a significant decrease in vision that glasses or contacts cannot fix.

3. Severe Corneal Thinning and Irregularity

When the cornea becomes extremely thin or steep, it's no longer structurally stable. This can pose a risk of rupture and cause severe vision loss. In such cases, corneal transplantation is considered to restore the integrity of the eye and improve vision.

4. Poor Vision Despite Other Treatments

If cross-linking (a procedure that strengthens the cornea) and custom contact lenses have failed to provide acceptable vision, and the patient’s quality of life is affected, a corneal transplant may be the best remaining option.

Types of Corneal Transplants for Keratoconus

There are two primary types of corneal transplant procedures for keratoconus:

• Deep Anterior Lamellar Keratoplasty (DALK): In this procedure, only the front layers of the cornea are replaced, leaving the inner layers intact. This reduces the risk of rejection and is often the preferred method for keratoconus.

• Penetrating Keratoplasty (PK): This is a full-thickness corneal transplant where the entire cornea is replaced. It's typically reserved for cases with significant scarring or when DALK isn't possible.

What to Expect After a Transplant

Corneal transplants have high success rates in keratoconus patients, but recovery can take several months. Vision may gradually improve as the eye heals, but patients usually still require glasses or contact lenses for optimal vision.

A corneal transplant is a major step in the treatment of keratoconus, but it’s also a potentially vision-saving procedure when all other options have failed. The key is early diagnosis and consistent follow-up with an eye care professional to monitor the disease and intervene before it reaches advanced stages.