• KERATOCONUS MANAGEMENT and Treatment Options

What is keratoconus?
Keratoconus is a corneal disease that occurs when the normally round dome-shaped cornea (the clear outer area of the eye) progressively thins causing a cone-like bulge to develop. Typically diagnosed during adolescence and early adulthood with a variable rate of progression.

The bulging or “cone-shaped” protrusion is caused by the normal pressure of the eye pushing out on the thinned areas of the cornea. Since the cornea is responsible for refracting most of the light coming into your eye, an abnormal-shaped cornea can create reduced visual acuity and affect the way you see. This reduced visual acuity can make even simple daily tasks, such as driving, watching television or reading, difficult to perform.

The actual cause of keratoconus is not yet known, but there have been studies to suggest a genetic and inherited link to the disease. Recent statistics estimate an incidence of greater than 1 in 1,000 based on computerized corneal topography, pachymetry, and higher-order aberrations. The condition affects male and female in equal proportion and occurs in both eyes in 90% of patients.

Prior to use of corneal collagen cross-linking 10% of keratoconus patients required a corneal transplant.

C3R – Corneal Collagen Cross Linking with Riboflavin

What is corneal collagen cross-linking with riboflavin (C3-R)?

To date, there has not been one successful way to stop the progression of keratoconus. With current methods using rigid contact lens or Intra Corneal Ring Segments, only the refractive error can be corrected, but it has no effect on the progression of the disease.

A new treatment for keratoconus, which has shown great success, is C3-R.

C3R is the application of Riboflavin Eye Drops on the cornea. Once absorbed by the cornea, UV-A light is applied for approximately 30 minutes. This combination increases the collagen cross-links to increase the mechanical strength of the stroma.

The method works by increasing collagen cross linkings, which are the “anchors” within the cornea. These “anchors” and formation of links between nearby filaments of collagen are responsible for preventing the cornea from bulging out and becoming steep and irregular. The procedure has been performed in Europe over the past six years. Clinical studies have demonstrated the safety and effectiveness of C3-R.

Description of C3-R:
The procedure is performed under a topical anesthetic (numbing eye drops). It involves gently removing the epithelium, the protective layer on the surface of the eye. A special type of Riboflavin eye drops are applied to the surface of the eye for approximately 30 minutes. The eye is then exposed to a safe amount of UV-A light for 30 minutes. After the treatment antibiotic and other eye drops are used and a protective bandage contact lens is inserted for four to five days. Postoperative instructions are given.

Intended benefits:

• Enhance corneal rigidity
• Increase the corneal resistance and biomechanical stability of the cornea
• Prevent disease progression
• May defer the need for a corneal transplant procedure
• May reduce the nearsightedness and astigmatism associated with keratoconus
• Enhance contact lens wear
• Reduce risk of ectasia with excimer laser treatment

INTACS or Intra-Corneal Rings:
Intacs were first introduced to the refractive surgery market approximately 10 years ago for the treatment of low myopia. The effectiveness of this product has been best demonstrated in patients’ with keratoconus. The Intracorneal ring is a clear, thin prescription insert that is placed in the periphery of the cornea to change the curvature of the cornea from within. With strategic insertion, the ICR can reduce irregularity caused by keratoconus without removing tissue and it is believed that it may delay the progression of keratoconus. Although extremely rare, the ICR can be exchanged or removed if needed. At the Bochner Eye Institute, we use the Intralase FS to create the channels in which the intracorneal ring is inserted.

Implantable Contact Lens
When a patient requires vision correction, but the cornea is too thin or the prescription is too high for laser vision correction, the Implantable Contact Lens is an option to consider. Patients with early stages of keratoconus have benefited from the Implantable Contact Lens. Your surgeon will assess your candidacy for this procedure during your evaluation. Please visit our Lens Implants page to learn more about the different types of treatment.

PRK
In some cases, PRK is a reasonable option for patients following C3R for vision correction Your surgeon will assess your candidacy for this procedure during your evaluation. Please visit our PRK page to learn more about this vision correction procedure.

Keratoconus treatment is only one of the specialties the surgeons at the Bochner Eye Institute are known for. In addition to the other procedures listed before, they are also noted Toronto LASIK surgeons.