Corneal cross-linking, or CXL, is an out-patient procedure to strengthen and stabilize a weak, unstable cornea. CXL is most commonly used to treat keratoconus patients or corneal ectasia occurring after refractive surgery. CXL is becoming more and more common around the world and at Finland Eye Center either on its own or as part of the Xtra procedures (see ‘PRK X’, ‘LASIK X’, ‘3D Z LASIK X’ leaflets for further information).
CXL creates new collagen bonds to strengthen the cornea by using a combination of ultraviolet light (UVA) and Vitamin B2 (riboflavin). This counteracts the effects of keratoconus and allows preservation of vision if done in early enough. At later stages, CXL can prevent vision deterioration and postpone the need for corneal grafting.
CXL is suitable for patients with a confirmed diagnosis of keratoconus or corneal ectasia (clinical examination and corneal topography). The current trend is to treat patients as early as possible, even children, with an upper age limit of around 40 years. Patients with very progressed conditions may be directed towards corneal grafts or other surgical intervention options as the benefits of CXL will be unlikely.
If you are pregnant or breastfeeding, please inform your doctor.
CXL can also be used for the following more rare conditions:
• forme fruste keratoconus
• pellucid marginal degeneration
• combined procedures (intracorneal rings, phakic IOLs)
• certain other corneal conditions
For example, the following patients are not suitable for CXL:
• herpes simplex keratitis patients
• riboflavin allergy
• aphakic eyes
• some systemic or autoimmune diseases
CXL is performed as an out-patient procedure in a treatment room under topical anaesthesia. The procedure can be done for one eye or both at the same time. First, the epithelium (superficial layer of the cornea) is gently removed or a flap is created using the Z LASIK or LASIK method. Riboflavin drops are administered to the exposed cornea after which UVA light is applied. After this, antibiotic eye drops are given and a soft bandage contact lens is placed to help the healing and re-growth of the epithelium. Alternatively, another method is the ‘transepithelial CXL’, which can be done without removing the epithelium. Sunglasses or other protective eyeglasses are recommended during the healing process. Please be assured that the UVA will not harm your eyes when applied properly.
You may experience some discomfort, tearing, sandy eyes and blurred vision for the first few days.
Once the epithelium has grown back (usually 4-7 days) the bandage contact lens will be removed. You may notice a drop in best corrected visual acuity during the first month, but this is normal. The final effects of the procedure should become apparent within the first year. However, it is important to understand that CXL will not cure the condition and it is not a vision improving procedure but a preservation of vision and prevention or postponing of further deterioration and more invasive treatments. Eyeglasses or contact lenses will therefore still be required though the prescription may change.
CXL is a safe procedure but as with any operation some complications and risks exist, which you must understand fully before undergoing CXL. Good patient selection reduces the complication rate to about 1% but risks associated with delayed healing time and a potential drop in best corrected visual acuity are possible.
It is essential that you make an informed decision taking into consideration the risks and benefits.
The CXL package includes the bandage contact lens, first week of medication, protective goggles and 3 months of follow-up visits. The package does not include further tools or procedures such as glasses, enhancement CXL, corneal rings, refractive surgery, contact lenses, or corneal grafts.
Intracorneal rings, or ICRs, are microthin curved implantable devices made of polymethylmethacrylate (PMMA) that are used to manage keratoconus. Please read ‘Keratoconus’ leaflet for more information.
By placing the rings inside the cornea, the steep cornea can be flattened and supported. Depending on the pattern and severity of the keratoconus, one or two rings may be implanted. You should understand that the aim of implanting ICRs is mainly to strengthen and stabilize, but not cure, your progressively weak keratoconus cornea. Although better vision is not the aim of ICRs, you may notice partial improvement but glasses or contact lenses may be needed to further improve vision.
To be a candidate, you should have a confirmed keratoconus diagnosis, age above 14 years, not too advanced keratoconus, not too thin corneas, and no other eye pathology especially allergy or excessive dryness. Also, you should be realistic with your expectations and willing to accept the potential risks associated with this procedure.
This out-patient procedure is simple and relatively painless, usually lasting 20-30 minutes. With anaesthetic drops, a tunnel is created by femtosecond laser according to individual pre-operative measurements. The ring(s) will then be inserted. If needed, a tiny suture may be used to close the opening. A bandage soft contact lens is placed.
To aid in proper sterile healing, you are advised to use antibiotic, anti-inflammatory and lubricant eye drops as well as eye shields that should be worn at bedtime for the first week. You may experience some discomfort, burning, foreign body sensation, unstable vision, glare, and haloes up to 3 months. The contact lens will be removed by the surgeon within the next day or two, while the suture (if any) will remain up to 1 month. Showering is to be avoided for a couple of days. You should be able to return to normal activities after a few days’ sick leave but rubbing your eyes must be avoided.
ICR implantation as any surgery can have complications, which should be considered before making a decision. These can be technical, such as failure to implant the rings, decentration of the rings or ring extrusion through the wound. You may notice dry eyes, uncomfortable glare and haloes. Delayed healing, unstable keratoconus, infections, inflammations, etc. are rare but possible complications. In some cases, the rings may need to be removed or replaced.
Note: Due to the progressive nature of keratoconus, most patients undergoing ICR implantation will also undergo corneal cross-linking (CXL, see ‘Corneal cross-linking’ leaflet for more information) after some months.Future procedures to further manage keratoconus are possible, such as corneal grafting. Further procedures will be charged accordingly.
Fundus fluorescein angiography (or FFA) is an investigation of the back of your eye (retina/fundus) that is done using a yellow fluorescein dye that is injected into your vein. This investigation is done to capture and highlight circulation issues such as leaking or blocked blood vessels in your eye and help to diagnose and follow retinal conditions.
First, your ophthalmologist and our anesthesiologist will assess your eligibility for FFA, including any allergies you may have or previous reactions to fluorescein dye. It is extremely important that you mention any previous reaction. If you are suitable, you will be asked to sign a consent form and your pupils will be dilated (contact lenses will need to be removed). A yellow fluorescein dye is then injected into a vein in your arm with a needle (like a blood test). As the dye travels to the blood vessels in the back of your eye (this only takes seconds), photographs are taken in rapid succession. During the investigation, you should be as still as possible while the photographs are being taken. The investigation takes about 15 minutes.
If you feel unwell at any point during the investigation, do not hesitate to inform the nurse or ophthalmologist (you will be accompanied by them throughout the procedure). It is quite common to feel slightly nauseous during the investigation, but usually this will pass within a few seconds. Taking deep breaths helps. Some patients may feel the need to vomit. Itchy, tingly skin or a rash can occur, which may be relieved by antihistamines if needed. Due to the yellow dye, your skin and urine will turn yellow for 1-2 days, which is completely normal. Drinking plenty of water after the investigation will help to flush out the dye. A small bruise may be visible at the site of the injection for a few days. If the dye is injected into the tissue outside the vein (due to needle displacement, movement, leakage, etc.), a burning sensation may be felt. If this happens, the investigation will be stopped and the burning will subside within a few days. A severe allergic reaction (anaphylaxis) to the dye itself is a serious but very rare side effect that can cause breathing or circulation difficulties. Finland Eye Center is fully equipped to manage such a situation. In the event of a side effect or poor cooperation by the patient (e.g. patient moving, blinking too much, etc.), it may be necessary to pause or stop the investigation and another session may be required or the FFA may need to be forgone altogether.
9 Color fundus img(a), early flurescein angiogram (b) and late fluorescein angiogram (c)
Your ophthalmologist will explain why you are advised to do an FFA investigation. Should you wish to not undergo the procedure or you are found to be unsuitable for it (such as a previous allergic reaction), you will be explained alternative investigations (if possible) and the consequences of relying on the alternatives instead. It is important to understand that certain conditions can only be diagnosed definitively and followed reliably depending on the results of an FFA, but of course it is your right to refuse the procedure. If you are particularly anxious about the procedure, you may discuss being given a mild sedative by our anesthesiologist to calm your nerves.
You will be asked to stay a while after your FFA investigation to ensure you are feeling well. Your ophthalmologist will review the findings and discuss them with you either soon after the investigation or at a separate appointment. It is advisable to bring sunglasses or a hat since your dilated pupils will make your eyes sensitive to light. For this reason and in case you are experiencing side effects, we recommend you have someone to take you home.
Phakic intraocular lenses (IOLs) are considered a type of refractive surgery, aiming to help patients to become glass independent.
At Finland eye center we offer Visian ICL/Toric ICL as well as Artiflex /Toric Artiflex phakic IOLs.
Phakic IOLs can be placed either in front of or behind the iris, in front of your natural lens.
Unlike in cataract surgery, your natural lens is not removed.
In simple terms, a phakic IOL is like a contact lens that is surgically inserted inside your eye rather than placed on the surface.
This offers a long -term solution to live a glass independent life. They function as a glass or contact lens, focusing light onto your retina to provide sharp vision. Phakic IOLs may result in even better visual acuity and contrast -sensitivity than with excimer laser procedures.
Before any decision, your eyes will be examined thoroughly and special measurements and investigations will be done to assess the anatomical features of your eye.
Each phakic IOL is custom ordered for each patient (and each eye), which is why it may take a few weeks to receive your phakic IOL.
Candidates who may have been told they are not eligible for laser vision correction, may be good candidates for phakic IOLs such as patients with high myopia or hyperopia, high astigmatism, thin or suspicious corneas and severe dryness for example.
Phakic IOL procedures are done in an operation theater (not in the laser suite). Usually , the procedure is done under general anesthesia although local or topical anesthesia is possible .The type of anesthesia will be determined through discussion and examination between you, your ophthalmic surgeon and anesthesiologist.
A small incision is made in the periphery of your cornea, through which the foldable phakic IOL is inserted either in front of or behind your iris . The procedure itself takes only a few minutes but operation theater protocols (preparation ,anesthesia and recovery from anesthesia ) will take some time. In addition , with Artiflex/Toric Artiflex IOLs , a small hole is made on the iris before, during or after the surgery (iridotomy or iridectomy) to reduce the risk of developing high intraocular pressure (IOP).
Once you have recovered from your anesthesia , you can go home but you need to have someone drive you.The eye will be covered with a protective shield. You will have an appointment the next morning and given antibiotic and steroid and steroid eye drops to use for a few weeks.Lubricating eye drops may be given as needed .You will see the difference in your vision at the first follow -up. Routine follow -ups will usually be after 1 day, 1 week and 1 month post -operatively .After that , regular follow -up is recommended as advised by your surgeon.Forcible eye rubbing should be avoided .
Phakic IOL implantation has a high safety and success rate but as with any procedure risks, complications and side-effects are possible , which should be considered before making a decision . Some temporary redness, foreign body sensation and visual disturbance may be noticed for a while .Temporary IOP elevation is also possible , although rarely chronic glaucoma may develop, which needs to be managed promptly .
Cataract development and corneal endothelium damage are very rare complications. Any residual refraction correction can be done by touch -up laser. Infection risk post-operatively is minimal.