Is this how you see the world?
- frustrating because glasses and regular contact lenses don’t give clear vision, and the world looks like what you see in the image above.
- a progressive, degenerative disorder.
- characterised by thinning and bulging of the cornea.
- a type of corneal ectasia.
- Glasses or soft contact lenses
- Complex contact lenses
- Collagen cross-linking
- Corneal ring segments
- Corneal transplant (keratoplasty)
Corneal EctasiaThis process of thinning and re-shaping of the cornea is called corneal ectasia. Keratoconus is just one of many types of corneal ectasia.The cornea is the clear, front surface of the eye and it helps to focus light onto the retina. Any distortion of the cornea leads to blurred vision, and the more advanced the keratoconus, the more blurred the vision will be.The real cause of keratoconus is unfortunately not fully understood, but it appears that there may be a genetic component and it’s believed that rubbing the cornea can speed up the degeneration. So controlling the itch that makes one want to rub one’s eyes is key in any keratoconus management plan. Usually keratoconus progresses faster in younger eyes, so it’s important we find these cases early in life, and treat them as soon as possible.Treatment options explained:Control the itchDo everything possible to reduce itchy eyes:
- Avoid the things that irritate your eyes.
- Wear sunglasses, glasses or goggles to shield your eyes.
- Use regular eye lubricant drops hourly to flush out pollens/irritants before they build up.
- Tightly squeeze your eyelids shut to secrete more oil to lubricate your eyes.
- Use cold ice-packs to soothe swollen eyelids and reduce the itchiness.
- Use eye drops such as Zaditen and Patanol as recommended by your optometrist.
- DON’T RUB YOUR EYES.
Complex contact lensesWhen soft lenses can no longer give clear vision, we have several options to choose from – rigid gas permeable (RGP), hybrid or scleral lenses. These are custom made for your eyes, from gas permeable materials, masking the abnormal shape of the cornea, and sharpening your vision.
Collagen cross-linking (CXL)
We recommend all keratoconics in their teens or 20s see an ophthalmologist as soon as possible in case CXL can stabilise the corneas at a time when the corneas are likely to progress the most.CXL strengthens the cornea by applying collagen and riboflavin (vitamin B2) to the cornea. There are 2 options, with the front layer/epithelium either left intact or removed, before the cornea is saturated with the solution and UV light applied, bonding the collagen strands into a meshwork that strengthens the cornea. Early treatment with collagen cross-linking can slow or even stop the progression of keratoconus. CXL takes about an hour and is performed by an ophthalmologist, who will review months later, and advise when the eyes are stable and ready to be fitted with contact lenses.
Corneal ring segmentsThis is a surgical option involving the insertion of clear plastic segments into the cornea. These segments are designed to reshape the front surface of the eye, thus correcting refractive errors caused by keratoconus. Corneal ring segments are reserved for advanced cases of corneal ectasia, where the patient’s vision is not correctable with glasses or contact lenses.Corneal transplantation (keratoplasty)This is an option only if all other treatments have been tried or ruled out. Fortunately, only 10–20% of keratoconic eyes eventually require corneal transplantation. There are two types of corneal transplants – partial-thickness and full-thickness – and it is usually the latter that is recommended for patients with keratoconus. A corneal transplant is a complex procedure but is only day surgery. It is usually performed under local anaesthetic, with the option of a sedative. During the procedure, your surgeon will cut out the abnormal section of cornea and replace it with donor cornea, which will be stitched into place. The stitches will be removed at a later date. Your own corneal cells will gradually grow around and fuse to the implanted cornea, and a full recovery might take up to a year. Crosslinking cannot be performed on patients:
- if their cornea is too thin (generally less than 350-400 microns)
- with an active ocular disease other than keratoconus
- with herpes simplex keratitis, a corneal infection caused by the herpes simplex virus (cold sore)
- who are pregnant
- with active, uncontrolled eye allergies
- with corneal scarring that significantly affects their vision