Keratoconus and corneal cross linking

The new technique of cross linking tested by Dr. Marco Lombardo

Dr. Marco Lombardo and his staff offer their expertise in the diagnosis and treatment of keratoconus. Dr. Marco Lombardo is actively engaged for years in the study and development of new non-invasive surgical techniques for the treatment of keratoconus, which include the most recent technique of transepithelial corneal cross linking using iontophoresis.

Keratoconus

Keratoconus is a degenerative disease of the cornea characterized by progressive thinning and bulging of the tissue. The clinical onset, usually bilateral, occurs in young people between 10 and 20 years of life. The cause is still unknown, although genetic factors have a very important role.
The first symptom is the loss of sight. Photophobia, glare to the light sources, monocular diplopia (double vision), and frequent eye redness are some of the symptoms that patients complain frequently.
The eye examination reveals, in the early stages, changes in the anterior (“striae of Bowman’s membrane”) or in the deeper (“Vogt’s striae”) portions of the cornea. In late cases, the physician may observe the typical protrusion of the cornea (the cone).
The diagnosis of keratoconus is done through the examination of the eye and the execution of corneal topography and corneal pachymetry.

Topografia CheratoconoCorneal topography of keratoconus. The areas with warmer colors (red) indicate steeper curvature of the corneal surface than surrouding areas. They correspond to the “base” of the cone protrusion.

Treatment of Keratoconus

In the early stages, keratoconus treatment makes use of eye glasses or contact lenses, which however do not slow down the eventual progression of the disease. Contact lenses permit better visual performance compared to the glasses, thanks to the fact that, being in contact with the corneal surface, are able to stabilize better the profile of the cone. In cases of progressive keratoconus the today’s election therapy is corneal cross linking. In cases of advanced keratoconus, a corneal transplantation can be indicated.

Corneal cross linking

A viable treatment option to slow down or halt the progression of keratoconus is offered by corneal cross linking. The scope of the cross linking procedure is to stiffen the cornea, weakened by the disease itself, through a chemical process called “photo-polymerization”. The corneal cross linking procedure consists in instilling drops of riboflavin (vit. B2) on the cornea (with or without the epithelium intact) and then to irradiate the cornea with a ultraviolet light beam (UV-A; wavelength: 370 nm). The procedure is painless and has a variable length depending on the technique (from 15 to 60 minutes).
The traditional technique of corneal cross linking involves the removal of the epithelium and has a total duration of about one hour. At the end of the intervention on the cornea is applied a bandage contact lens which is removed after a few days. The patient is prescribed a therapy based on antibiotics and anti-inflammatory eye drops for a few weeks.
The results of eight years have demonstrated the efficacy and safety of the corneal cross linking procedure. On average, there is a significant flattening of the apex of the cone (an average of 1-2 diopters), with a simultaneous improvement in visual acuity in some cases.

Corneal cross linking transepithelial with iontophoresis

With the new technique of corneal cross linking, the corneal epithelium is not removed anymore. Recently, the corneal cross linking can be performed using iontophoresis. Iontophoresis is a technique that allows the administration of riboflavin in just five minutes and without removing the epithelium. The UV-A corneal irradiation is performed with a new lamp in just nine minutes. Dr. Marco Lombardo is one of the developers of this new technique of corneal cross linking with iontophoresis.

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Frequently Asked Questions on corneal cross linking

Who can undergo to corneal cross linking?

The indication for corneal cross linking is limited to the progressive keratoconus, with or without decreased vision and corneal thickness greater than 400 micrometres.

The intervention of corneal cross linking is dangerous?

The corneal cross linking is a safe procedure if the patient is selected correctly and if the treatment is performed by qualified personnel.

What happens after the intervention of corneal cross linking?

In the first days after surgery, vision can be blurred and the patient can experience a few discomfort (for example, foreign body sensation, watery eyes). This happens mainly because the removal of the epithelium leaves a sort of scratch on the cornea which then leads to eye discomfort.

The bandage contact lens is removed after 3-5 days, and then the vision tends to improve progressively over time. The effectiveness of the treatment can be estimated at approximately 6 months after surgery. For this reason, repeated checks are required and prolonged care that must be modulated on the basis of the clinical findings.
The new technique of corneal cross linking with iontophoresis does not decrease vision and does not give rise to eye discomfort, except for the first day after surgery.

The intervention of cross linking does improve vision?

The most important outcome of corneal cross linking is the stabilization of keratoconus. The reinforcement of the corneal collagen determines, therefore, stabilization of vision. In almost all cases, there is even a slight reduction of astigmatism, which also results in a slight improvement of vision.

The surgery eliminates the use of glasses or contact lenses?

No, the intervention of corneal cross linking is not a refractive surgery. If you took a pair of glasses before surgery, your will wear the same eye glasses after. The same must be said for the contact lenses. It should be noted, however, that frequently there is a better tolerance to contact lenses after the treatment. A new contact lens can be worn after about three to six months after surgery.