Stabilizing Corneal Diseases (Keratoconus) through a Keraring Implant

Keratoconus is a genetically inherited disease that effects the normal shape of the cornea, causing it to lose its stability and bow forward irregularly, which results in a reduction and distortion of vision.

A Keraring implant with the femtosecond laser can stall this progressive protuberance of the cornea. Generally, the implants stabilize the cornea and thereby also stabilize the vision. An improved adaptation of glasses or contact lenses is thus possible.


You can see how exactly the surgery works in the video


Are you suffering from keratoconus and are you considering a long-term solution?
We will provide you with an overview of the clinical picture and the suitable treatment method.

What is Keratoconus?


The word Keratoconus derives from two Greek words: "kerato", which means cornea, and "conus", which means cone. Keratoconus is a genetically inherited disease that effects the normal form of the corneal shape, causing it obtain a cone-like shape–the reason for the reduced vision.

The Keraring is mostly implemented when the disease has reached its advanced stages and contact lenses have become intolerable, or the corneal shape too irregular. The Keraring can stall this progressive curving of the cornea, and thereby indefinitely postpone the need for a corneal transplant.


Treating Keratoconus:

  • Glasses:
    in the early stages
  • Hard contact lenses:
    when glasses are no longer sufficient
  • Implantation of corneal rings:
    when contact lenses have become intolerable, or the protuberance is increasing
  • Corneal transplant:
    In the final stages (carried out in the laser eye clinic in Munich): A LASIK surgery to improve the vision is not possible in this case.


Keraring Procedure

The Keraring Procedure – Step by Step 


First, a tunnel is prepared for the ring to be inserted into. EuroEyes uses the femtosecond laser for this–just like in the Femto LASIK treatment–which makes the most precise incisions within 6 seconds.  


The ring is then inserted carefully into this tunnel, and carefully positioned. 


The rings "tighten" the corneal cone and thereby create a more regular corneal surface.

Treatment Procedure

1.  Personal, Non-binding Consultation

  • All relevant eye parameters are measured
  • Examine your eyes to make sure you are a suitable candidate for the Keraring treatment




2.  A Thorough Medical Preliminary Examination

  • The examination usually lasts about two hours
  • Intensive ophthalmic preliminary examination and measurement of your eyes
  • Our Specialists in ophthalmology will explain every detail about the treatment
  • Before this preliminary examination you should not have worn soft contact lenses for one week and hard contact lenses for two weeks
  • Please note that after the examination you will not be safe driving a vehicle–neither car, nor motorcycle or bicycle. We therefore recommend that you take a cab or public transportation
  • At the examination you will receive an after-care set for the days after your treatment. The medication and content will be explained in detail by our staff


3.  On the Day of Your Keraring Treatment

  • We recommend that you wear comfortable clothes on the day of treatment
  • You can eat and drink normally on the treatment day, but please do not smoke
  • For hygiene reasons, it is also important that you wash your face thoroughly prior to treatment, completely remove makeup, and avoid perfume
  • Anesthetic eye drops
  • Outpatient surgery, no bandage, and sunglasses are recommended
  • The total duration of the surgery (one eye): approximately 10-15 minutes
  • You are not allowed to drive a vehicle after the procedure


4.  After the Keraring Surgery

  • The eye can be a little red–please do not rub your eyes
  • How and when to use the antibiotic eye drops, the combination product that has a preventive effect against swelling and inflammation, and the pain-relieving eye drops will be discussed with your doctor beforehand
  • Return to work after 2 days
  • Resume sports activities after approximately 3 days, swimming and sauna after approximately 2 weeks
  • Post-operative follow-up examinations: after 1 day – 1 week – 1 month
  • You may drive a vehicle again only with the doctor's permission, normally after the 1 week post-operative examination

Good to Know

This is the Most Modern and Safe Treatment Method of Keratoconus

The keraring is made out of artificial material, Perspex CQ Acrylic, which is the same material used for more than 20 years for cataract treatments, and is therefore tolerated so well by the cornea that no risk of rejection exists.


  • The eye quickly recovers from the surgery, and the vision therefore improved within a couple of days, and stabilizes within 3 to 6 months. During this time, vision fluctuations can occur. It may be necessary to wear glasses or contacts after the surgery–even though the vision, despite a small remaining refractive error–will be pretty good.
  • The succes of the surgery depends on the severeness of the corneal disease. The earlier this treatment is carried out, the greater the success rate. If carried out in time, as much as 95% of all progressive cases can be stopped.
  • The risk of complication is very low, however, as by any other surgery, an infection may occur. Complications are generally not severe, and in case they do occur, this treatment is reversible and the rings can be removed, allowing the cornea to return to its original shape.

Corneal Collagen Cross Linking

Corneal collagen cross-linking aims to increase the biomechanical stability of the layers of corneal stroma by creating and increasing cross-linkage between the collagen fibres. As a result the cornea is strengthened and progression of the condition is halted. In a significant number of patients the ectasia has been reduced, in turn reducing the degree of astigmatism.

This is a new procedure which is still under evaluation but offers the potential to minimise the impact of keratoconus so that patients achieve a stable prescription that can be corrected by spectacle or soft contact lens wear.


How Treatment is Applied

Corneal collagen cross-linking is carried out as an outpatient procedure in the operating theatre under topical anaesthetic.

  • The eye to be treated is anaesthetised with eyedrops.
  • The area around the eye is thoroughly cleaned.
  • A clip is inserted to support the lids and hold the eye open.
  • The corneal epithelium is gently removed. A solution is applied to soften the epithelial cells which can then be wiped away.
  • Drops of a riboflavin solution are applied to the exposed cornea at regular intervals until the cornea is fully permeated.
  • The thickness of the cornea is checked to ensure that the UV light can be applied safely. Ultraviolet A light is applied to the cornea for 30 minutes during which time further riboflavin drops are applied together with artificial tears to keep the eye well lubricated.
  • On completion of the UVA irradiation antibiotic eyedrops are applied and a bandage contact lens is fitted to protect the cornea and keep the eye as comfortable as possible while the corneal epithelium heals.
  • A protective shield is worn for the remainder of the day of treatment and overnight for the first three nights.

Following the treatment there is some discomfort and the eye is likely to be gritty, watery and light sensitive until the corneal epithelium has healed. This can be helped by plenty of sleep or resting with the eye gently closed in a darkened room. A course of antibiotic and steroid drops is given to ensure the eye heals safely. The bandage contact lens will be removed a few days after treatment.

Further follow up consultations are held at intervals until the treated cornea has stabilised. If both eyes are affected by keratoconus then the second eye can be treated at this stage.


Risks of Corneal Collagen Cross-Linking

Until the corneal epithelium heals there is a risk of infection and the antibiotic drops supplied must be used as prescribed. There may be some corneal oedema following the treatment and this will be controlled by using the steroid drops given.

The ultraviolet A light used is applied in a carefully measured and even pattern over the cornea and the thickness of the cornea is checked to ensure that the irradiation will be absorbed by the riboflavin and will not damage the deeper structures of the eye.

Frequently Asked Questions about Kerarings