EYE CLINIC

KERATOCONUS | EYE CLINIC - EMMETROPIA

What is keratoconus?

 

Keratoconus is a serious but treatable disease of the cornea.

Keratoconus occurs when the cornea - the clear front surface of the eye in the shape of a dome – gets thinner over the years and gradually swells outwards in the shape of a cone. Simultaneously with the progressive thinning of the cornea, scarring and eventually blurriness are observed in the area where the cone is.

This cone on the cornea causes distorted vision and may cause sensitivity to light. Keratoconus usually affects both eyes and generally its first symptoms appear in patients aged between 10 to 25 years. This condition can develop slowly over decades or more, but, in some cases, it can develop at a faster rate.

In the early stages of keratoconus, vision problems can be treated with glasses or soft contact lenses. Later, hard, air-permeable contact lenses or other types of contact lenses may need to be used.

Patients with advanced keratoconus may need a corneal transplant. The important thing about the disease is that it causes progressive, partial or total vision loss, and if left untreated, it can even lead to blindness.

 

Symptoms of keratoconus

 

Symptoms of keratoconus may change as the disease progresses and may include:

 

• Blurred or distorted vision
• Increased sensitivity to light (photosensitivity)
• Problems with night vision
• Frequent changes in glass prescriptions
• Sudden deterioration and decreased vision

In some cases, keratoconus can develop quite rapidly and can cause a sudden decrease in vision and scarring in the cornea. This is caused by a condition in which the inner corneal layers cornea rupture, allowing fluid to swell the cornea (Hydrops).

In advanced keratoconus, the cornea can be scarred, especially when the cone is already formed. A scarring cornea exacerbates vision problems and may even require corneal transplant surgery.

 

Causes of keratoconus

 

Despite ongoing research, the etiology of keratoconus remains virtually unknown.

It is generally considered as an inherited disease with genetic and environmental factors involved in its occurrence. About 1 in 10 people with keratoconus also have a parent with the same condition. In the past, it was considered a rare condition, perhaps because there were no diagnostic tools to detect it at an earlier stage. Today we know that it is not so rare. In Greece we have more than 20,000 people (about 2 per 1,000 inhabitants) with keratoconus.

 

Risk factors

 

The following factors have been associated with an increased chance of developing keratoconus:

 

• Family history of keratoconus
• Intense rubbing of the eyes
• Diseases such as Retinitis Pigmentosa, Down syndrome, Ehlers-Danlos syndrome, allergic rhinitis and asthma

 

Diagnosis of keratoconus

 

To diagnose keratoconus, the ophthalmologist will examine the patient's medical and family history and perform a complete ophthalmological examination. In addition, we should proceed with measurements and tests that will provide further information about the curvature and shape of the cornea.

Measurements and tests to diagnose keratoconus include:

• Refractive examination: During which the ophthalmologist accurately examines the patient's vision
• Slit lamp examination: In which the ophthalmologist directs a vertical beam of light to the cornea using a low-power microscope in order to evaluate the shape of the cornea while also looking for other possible eye problems.
• Keratometry: With this fully automated measurement the ophthalmologist can quickly know the curvature of the cornea in each eye
• Corneal mapping: Using special equipment such as OCT (Optical Coherence Tomography) and state-of-the-art corneal topography, complete corneal mapping of each eye is performed. These measurements provide important information about the surface area, the thickness and curvature of the cornea in order to decide your treatment plan.

 

Treatment of keratoconus

 

The treatment of keratoconus depends on the severity of the condition and how quickly the condition progresses.

Mild to moderate keratoconus can be treated with glasses or contact lenses. In most patients, the cornea will stabilize after a few years and they are unlikely to have serious vision problems, so they do not need further treatment.

We have several options of treatment with glasses and / or contact lenses which include the following:

 

• Glasses or soft contact lenses: Glasses or soft contact lenses can correct blurred or distorted vision in the early keratoconus. Patients need to change them frequently as the disease progresses and the shape of the corneas changes
• Hard contact lenses: These hard, air-permeable contact lenses (RGP- Rigid Gas Permeable) are often the next step in treating advanced keratoconus. Hard lenses may be uncomfortable for patients at first, but most of them adapt to their use as they can provide excellent vision. This type of lenses can be customized in order to fit each patient's cornea
• Piggyback contact lenses: If the contact lenses are not tolerated by the patient, the ophthalmologist may recommend "piggybacking", i.e. a hard contact lens over a soft one that will be easily tolerated by the patient
• Hybrid lenses: These contact lenses are rigid in the center and softer on the outer ring for better comfort. People who can't stand hard contact lenses may prefer hybrid lenses
• Scleral contact lenses: These lenses are useful when we have very irregular changes in the shape of the cornea in advanced keratoconus. Instead of touching the cornea, as traditional contact lenses do, the scleral lenses touch the white part of the eye (sclera) and create a dome over the cornea without touching it

 

If you use hard or scleral contact lenses, make sure they are applied by an ophthalmologist or optometrist with experience in treating keratoconus.

You will also need to have regular check-ups in order to see if the lens fitting stays optimal over time as an inappropriate contact lens can further damage the cornea.

 

Interventions of keratoconus

 

• Corneal Crosslinking (CXL): In this type of keratoconus surgery, special ultraviolet (UV) light and appropriate eye drops (riboflavin - Vitamin B2) are used to strengthen the cornea. This process helps to flatten and harden the cornea by preventing further development of the keratoconus. Clinical research globally showed that this type of surgery enhances the micro-architecture and internal structure of the cornea. For more details on Corneal Crosslinking (CXL) click here
• Corneal Transplantation: When the symptoms are severe, your ophthalmologist may suggest a corneal transplant. Your ophthalmologist will replace all, or part of your diseased cornea with healthy corneal donor tissue. For more details on corneal transplants click here

 

Why Emmetropia

 

The Emmetropia  Eye Clinic as a center of excellence was the first  to bring this technology in Crete and second in the country in 2006. Therefore, we are the clinic with the largest   cumulative clinical experience in Crete and also in whole Greece with over 1500 surgeries of this kind.

At Emmetropia Eye Clinic, we are investing in new technology to ensure that all measurements, examinations, and of course treatments are performed accurately.

Emmetropia has one of the most modern collagen crosslinking systems - AVEDRO Rapid Crosslinking - for the treatment of keratoconus combined with the latest generation of corneal mapping with PENTACAM.

The Emmetropia Eye Clinic is also one of the few centers in the world that, in collaboration with the University of Wenzhou (China), are mapping DNA abnormalities in keratoconus for future gene therapy.

Our medical staff will inform you and advise you in detail on the best possible solution.

We have a special section for glasses and special department for different types of contact lenses fitting. Our state-of-the-art technology for performing keratoconus treatments and dealing with other diseases can guarantee the best possible result for your eyes.