Keratoconus and CXL
What is Keratoconus?
Keratoconus is an eye disease that causes the cornea to thin and bulge out like a cone which ultimately keeps the light rays out of focus and the vision gets blurry or distorted. In this condition, the daily activities are hampered and an individual can experience difficulties in reading or driving. Though no prime cause is discovered about why people develop keratoconus, it might be genetic or can be caused due to eye allergies, excessive eye rubbing, and connective tissue disorders like Marfan Syndrome and Ehlers-Danlos Syndrome.
Also, keratoconus affects people in their teenage years and slowly gets worse over a period of about 10 or 20 years, affecting both eyes and causing different visions.
As keratoconus progresses the signs and symptoms also advance and change. Some noticeable symptoms include:
- Blurry vision
- Double vision
- Clouding of vision
- Eye strain, eye pain
- Headaches
- Sensitivity to light and glare
- Seeing halos around bright lights or ‘ghosting’
- Frequent changes in spectacle prescriptions
While it is still not clear what causes keratoconus, studies and research suggest there is a genetic component. Some factors that could have a link to keratoconus include:
- Age
- Race
- Family history
- Certain medical disorders/conditions
- Inflammation
Beyond this, eye rubbing and other forms of corneal microtrauma have been shown to induce and exacerbate keratoconus in those who are susceptible.
Keratoconus Treatment
While the corneal damage that has occurred due to keratoconus cannot be reversed, there are certain treatment options that help slow down the progress of keratoconus and potentially can improve your eyesight.
The best person to judge which treatment options are most suitable is your ophthalmologist. Depending on your symptoms and the stage of the condition, the eye specialist may recommend one of the following as treatment for keratoconus:
- Non-Surgical Treatments (For Mild to Moderate Cases)
- Glasses & Soft Contact Lenses: can be used in the early stages of keratoconus. However, as the cornea becomes more irregular, glasses no longer provide clear vision.
- Rigid Gas Permeable (RGP) Contact Lenses: These are hard lenses that provide a smooth optical surface for clearer vision but cause mild discomfort. Also, as the keratoconus progresses, frequent fitting adjustments are needed.
- Hybrid Contact Lenses: Much more comfortable than RGP lenses, Hybrid contact lenses provide clear vision as they are made of a hard center (for vision correction) and soft edges (for comfort).
- Scleral & Semi-Scleral Lenses: They are also more comfortable than the RGP lenses and provide excellent vision correction. These lenses have a large diameter that rests on the white part of the eye instead of the cornea. Perfect for moderate to severe keratoconus.
- Medical Procedures (For Progressive Cases)
Corneal Cross-Linking (CXL): CXL strengthens and stabilizes the cornea to slow or stop the keratoconus progression. In this procedure, a vitamin B2 is applied to the cornea and is exposed to UV light to strengthen collagen fibers. CXL is performed to prevent further bulging of the cornea and reduce the need for corneal transplants in future. Though CXL stops keratoconus progression it doesn’t reverse the damage.
- Surgical Treatments (For Advanced Cases)
Intacs (Corneal Implants): is a procedure that improves vision by flattening the cornea. In this procedure, small, curved plastic inserts are placed within the cornea and is a less invasive procedure than a corneal transplant.
Corneal Transplant (Penetrating Keratoplasty or DALK): A rather complex process, corneal transplant replaces the damaged cornea with a healthy donor one. It is of two types:
- Full-thickness transplant (Penetrating Keratoplasty – PK) → Entire cornea is replaced.
- Partial-thickness transplant (Deep Anterior Lamellar Keratoplasty – DALK) → Only the outer layers are replaced, preserving inner corneal layers.
Best for: Severe keratoconus with corneal scarring or extreme thinning.
Success Rate: High, but recovery can take months to years.
While the corneal damage that has occurred due to keratoconus cannot be reversed, there are certain treatment options that help slow down the progress of keratoconus and potentially can improve your eyesight.
The best person to judge which treatment options are most suitable is your ophthalmologist. Depending on your symptoms and the stage of your condition, the eye specialist may recommend one of the following as treatment for keratoconus:
- Prescription glasses
- Contact lenses
- Corneal ring segments
- Corneal collagen cross-linking
What is CXL ?
Collagen crosslinking (CXL) is an outpatient procedure that can quite easily be carried out in an office setting. A specific UV light delivered from a special machine is used to strengthen the cornea after it has been soaked with riboflavin (vitamin B2) eye drops. What “cross-linking” does is creates bonds between the collagen fibers in the cornea, like scaffolds, that strengthens the corneal tissue and helps it remain stable so that the thinning and bulging can be slowed down or stopped.
Why is CXL important? Because, it is the only treatment that can prevent progressive keratoconus from becoming worse. If left unchecked, keratoconus can damage the cornea completely and then the only option left is a corneal transplant, which is major surgery. Good evidence shows that a single treatment with CXL can halt the progression of keratoconus in 95% of people.
During the CXL procedure you are administered eye drops to numb your eyes. After removing the epithelium, or surface layer of the cornea, specially formulated riboflavin (vitamin B2) eye drops are instilled in your eye. Once the drops have soaked into your cornea, usually 30 minutes, the cross-linking can commence. This involves concentrating and looking at the UV light as more riboflavin eye drops are instilled into your eye. At the end of the procedure, a bandage contact lens is placed on the eye to help protect it until the epithelium heals.
A CXL procedure is not the same as LASIK. It only helps halt the progression of keratoconus and in no way tries to change the vision. Many people continue to use glasses or contact lenses even after having had the CXL procedure.
Who should get this treatment ?
CXL is only helpful if your keratoconus is progressing. Your ophthalmologist will be able to determine if your keratoconus is indeed getting worse, and if so, which eye is accelerating the quickest.
But before finding out who should get this treatment, it’s important to understand that a CXL surgery does not reverse the effects of keratoconus in the cornea. It merely slows down the condition and prevents it from becoming worse. Only your doctor can decide if you are a suitable candidate for CXL surgery.
Now let’s find out why some people should not delay being diagnosed with keratoconus and potentially having a CXL procedure for too long.
In cases where there is a strong family history of keratoconus, it is always best to keep a watch on the eyes, especially after the age of 15. This is because most cases of keratoconus begin in the late teens.
Those who have conditions such as Ehlers-Danlos syndrome, Down syndrome, retinitis pigmentosa, and osteogenesis imperfecta are prone to keratoconus.
The tissue of the cornea can be adversely affected in people who have allergies, asthma, eczema or allergic (atopic) eye disease. These patients have a tendency to rub their eyes, increasing the risk of keratoconus. Read here
Never delay a check-up or wait it out. Going for an immediate eye check can save you a lot of trouble later.
Recovery Time
In the early stages of keratoconus, glasses and contact lenses give immediate relief. However, vision correction is temporary and needs frequent changes. If the case is moderate, corneal cross-linking is done and it usually takes 1-2 weeks for the patient to recover followed by blurry vision, mild pain, temporary light sensitivity, and discomfort for a few days. Full recovery takes 6 months.
In the cases of corneal implant, patients may feel mild discomfort in the initial 2 to 3 days while the vision stabilizes in the first 3 months. Contact lenses may still be needed for best vision correction.
On the contrary, corneal transplants take 1-2 weeks before the healing begins and take up to 1 year to fully recover with stabilized vision. However, stitches may stay in for months to a year and eye drops are advised for a year to avoid rejection.
Estimated cost involved ?
A relatively new procedure, CXL is being widely used in Australia on patients with keratoconus.
In a private setting patients may have to pay around $2500 to $4000 per eye for CXL. Medicare will provide a rebate of about $1500 per eye. Unless undertaken in a hospital, private health insurance does not cover the procedure.
FAQ's
On the day of the procedure, avoid wearing any eye makeup. Have a light meal and keep yourself adequately hydrated. Get family or friends to drive you home after the procedure. You should not drive for the first few days after the procedure. Understand the post-op care that you will need to take and follow accordingly.
Only one eye will be treated at a time. If both eyes have progressive keratoconus, the decision on how soon the other eye will be treated is best left for your doctor.
The CXL procedure is not the same as LASIK. It is undertaken to slow or stop the progression of keratoconus. Very rarely does it change the vision or make it better. In most cases patients have to continue to wear prescription glasses or contact lenses for their vision even after the CXL procedure.
Slight irritation or a grainy feeling in the eye with watering may persist on the day of treatment. Pain usually subsides after 24-48 hours of treatment. To combat dryness of the eyes you will need to use tear lubricants for at least 2 to 4 months. Serious side effects such as corneal scars, endothelium burns, corneal infections, or corneal haze, are extremely rare.
After care is easy and simple. The eye that has been treated is checked a few days after the procedure and again a week later. The next follow-ups happen 6 weeks, 3 months, 6 months, 1 year, and 2 years after the procedure.