Contact Lenses in Keratoconus

Keratoconus is a corneal disease in which the cornea thins and takes on a cone-like shape, causing distorted vision and irregular astigmatism. One of the key pillars in its management is the use of specialized contact lenses, which help improve vision when glasses are no longer sufficient.

Soft Contact Lenses in Keratoconus

Spherical soft lenses:

They are usually of little use, even in mild or early keratoconus, since most patients present with significant astigmatism. For this reason, they rarely provide good visual quality.

Toric soft lenses:

In some cases of mild or early keratoconus, toric lenses may be an option, as long as the lens remains stable and does not rotate excessively on the corneal surface.

Rotation and stability of the lens depend directly on the degree and regularity of astigmatism.

When the lens remains stable, it can be acceptable, though still limited compared to rigid lenses.

Rigid Gas Permeable (RGP) Lenses

Currently considered the first-line option for many patients with keratoconus.

Advantages:

Provide the best visual quality in most cases.

Allow patients to achieve their maximum possible visual acuity.

Relatively affordable compared to other alternatives.

Disadvantages:

May be uncomfortable for some patients.

In advanced cases, discomfort may be so significant that the patient cannot tolerate them.

Scleral Contact Lenses

These are specially designed lenses that cover the entire cornea and rest on the sclera (the white part of the eye).

Advantages:

Excellent comfort, even for highly irregular corneas.

Can be adapted in advanced keratoconus with high corneal aberrations.

Disadvantages:

More complex fitting process, requiring specialized optometrists and longer adaptation time.

Usually more expensive than other contact lens options.

Piggyback Contact Lenses

The piggyback system combines two lenses:

• A soft lens underneath (for comfort).

• A rigid lens on top (for visual quality).

Advantages:

Offer the visual quality of rigid lenses with the comfort of soft lenses.

More affordable than scleral lenses.

Disadvantages:

More complex care and fitting process.

Not all patients are candidates.

Duration and Follow-Up

The average lifespan of any keratoconus contact lens is 1 to 2 years, depending on use, material, and care.

Regular follow-up with both ophthalmology and specialized optometry is essential to monitor corneal health, fitting, and lens stability.

Conclusion

Contact lenses are a fundamental tool in the management of keratoconus. The choice of lens type depends on:

• The stage of keratoconus.

• The patient’s tolerance.

• The cost-benefit balance.

• The experience of the ophthalmologist and optometrist in specialized fittings.

With proper monitoring, lenses allow patients to achieve excellent visual quality and delay or avoid more invasive surgical treatments.