Cornea

What is Keratoconus?

Keratoconus is a progressive disease that affects both eyes and is characterised by the bulging and thinning of the transparent layer (cornea) that forms the front part of the eye. It is also known as corneal sharpening.

Cornea is the most important eye layer where the rays coming to the eye are refracted. Changes occurring in this region cause the rays to focus incorrectly and seriously impair the quality of vision. The most important complaint in this disease, which is more common in people with a family history and allergic constitution, is low vision that cannot be corrected with glasses.

Keratoconus usually starts at the age of 15-16 and can progress up to the age of 35. The course of the disease may vary from person to person. In the early stages of keratoconus, the complaint is usually the frequent change of the spectacle number. As the disease progresses, a clear vision cannot be achieved with glasses.

Treatment of Keratoconus

Since the course and rate of progression of the disease can develop extremely differently, keratonus treatment is individualised.

There may be patients who can see clearly without using glasses and are unaware of their disease, as well as cases that progress extremely rapidly and require corneal transplantation in their twenties.

In fact, there is no complete treatment for keratoconus, which is a structural disease.

The aim of the treatments is to achieve a quality of vision that patients can continue their lives comfortably.

CCL - ( Corneal Cross - Linking )

It is a method that has been used with increasing frequency in the last 5 years and stops the progression of keratoconus. Ultraviolet A and Riboflavin (vitamin B2) are used to strengthen the structure of the cornea.

Therefore, it is the first treatment option in patients with progression, regardless of the level of the disease and the quality of vision of the patients. CCL not only stops the progression of keratoconus, but also provides some increase in visual acuity in some patients.

Method

After the eye is anaesthetised with drop anaesthesia, the epithelial layer of the cornea is peeled off. Riboflavin solution is instilled into the eye for 30 minutes at 5 minute intervals. Then 370 nm UVA is applied at a distance of 4-5 cm from the corneal surface in an area of approximately 8 mm for 30 minutes.

Riboflavin is continued to be instilled every 5 minutes during UVA application. After the procedure, the eye is closed with antibiotic pomade.

The average recovery period is 2 days.

Contact Lens

The shape of the cornea is distorted in keratoconus. Mild astigmatism seen in initial keratoconus can be corrected with soft lenses. As keratoconus progresses, even keratoconus-specific soft lenses cannot improve vision.

For this reason, semi-soft, hybrid (hard centre, soft periphery) and piggy-back (soft and semi-soft lenses together) contact lenses are applied. However, contact lenses do not prevent the progression of keratoconus. Patients using contact lenses should be routinely checked and CCL treatment should be applied when necessary. After this treatment, contact lens use is continued for good vision.

Corneal Rings (Keraring, Ferrararing, Intacs)

They are transparent, tissue-compatible, tissue-compatible, glass-derived implants that are mounted inside the corneal tissue deteriorated in keratotoconus. Since they are placed inside the cornea, it is not necessary to wear and remove them like contact lenses.

They can remain in the eye for a lifetime without any problems and can be removed from the eye at any time. Although there are ring segments in different brands and structures, they all have the same mechanism of action.

The aim here is to make the deformed cornea more smooth and to ensure the correct refraction of the rays coming to the eye.

Method

After the eye is numbed with drop anaesthesia, a tunnel of desired depth and diameter is created in the cornea with Femtosecond (Intralase) laser. After this procedure, which takes approximately 10 seconds, the ring pieces are placed into the cornea with the help of a special clamp. The eye is not closed after the treatment.

We have been performing ring implantation in our clinic since 2006. In the last few years, we have been combining this treatment with CCL treatment to stop the progression of keratoconus and to provide a better visual result to our patients.

Keratoplasty (Cornea Transplant)

It is a preferred method when keratoconus progresses and the cornea loses its transparency or when other methods do not yield positive results. Keratoplasty, popularly known as eye transplantation, is actually an operation in which the cornea of the eye, which has deteriorated only as a result of various diseases, is replaced with a donated cornea.

In corneal transplantation surgery, a circular piece, which can be 6-9 mm in diameter, is removed from the donated healthy cornea and a piece of the same size is removed from the recipient's (patient's) cornea and sutured to this area. The surgery is preferably performed under general anaesthesia.

Prepared by the Editorial Board of Göz Vakfı Hastaneleri.