Keratoconus

Keratoconus

Modern technology has changed the way we think about keratoconus.

Now there are options to improve your vision or possibly even give you freedom from glasses and spectacles all together.

Now there are options to improve your vision or possibly even give you freedom from glasses and spectacles all together.

What is keratoconus?

We see through the cornea, which is the clear front window of the eye. A normal cornea has a dome shape, like a ball. In keratoconus, however, the structure of the cornea is just not strong enough to hold this round shape. The cornea bulges outward and downward like a cone. The misshapen cornea can result in blurred or distorted vision, glare and halos at night, and the streaking of lights.

Between age 12 and 35 it can arrest or progress at any time. It is impossible to predict how fast it will progress or if it will progress at all. After age 35 progression slows and often stops. With severe keratoconus, the stretching of collagen fibres can lead to tears at the back of the cornea. It can swell and take months for the swelling to go away. This often causes a large corneal scar that impairs vision. Keratoconus should be diagnosed, followed up and treated to prevent complications. If you struggle to see with your glasses and your vision continually deteriorates, ask your eyecare professional to screen for keratoconus.

Why can I not see well with my spectacles?

Patients with Keratoconus often just can’t get spectacles or contact lenses that help them to see clearly. Higher-order aberrations (HOAs), which cannot be corrected by spectacles, are more subtle and complex refractive errors than near-sightedness, farsightedness and astigmatism. These optical and anatomical irregularities can cause difficulty seeing at night, glare, halos, blurring, starburst patterns, distorted images or double vision.

Speciality contact lenses can effectively neutralise many of these visual symptoms by masking the irregularities on the front part of the cornea. There are different lens options like speciality soft, corneal gas permeable lenses, hybrid and scleral lenses. Your Optometrist will choose a lens that will work for you based on the severity of your keratoconus.

Why can I not have LASIK?

If you have keratoconus, you should not have LASIK because it can further weaken the cornea and make vision worse. Modern diagnostic and patient screening protocols are designed to help ensure LASIK is only recommended to good candidates for the procedure with a high probability of success. Any candidate for LASIK is thoroughly screened for keratoconus. Anyone with even a small degree of keratoconus should not have LASIK surgery.

If you are diagnosed with keratoconus and told you are not a good candidate for LASIK, it is strongly recommended you take the advice of your surgeon. This does not mean that spectacle independence is necessarily impossible. There are other options and vision correcting procedures that may be better suited to you.

How do I stop keratoconus from getting worse?

Albert Einstein said: “Intellectuals solve problems, geniuses prevent them”. The essential treatment anyone with progressive keratoconus should have is called cross-linking. This can stop your keratoconus from getting worse and protect the vision you have left. Cross-linking can prevent your keratoconus from progressing to the point where you might need a corneal transplant. With collagen cross-linking your ophthalmologist uses a special UV light and eye drops to strengthen the tissues of the cornea. More cross-links in the corneal structure form, leading to a stronger cornea. Doing this also helps to flatten your cornea, keeping it from bulging further.

What does the journey to spectacle and contact lens freedom look like?

With modern technology, there are options to improve your vision or possibly even give you freedom from glasses and spectacles all together.

Different procedures can be combined to gradually improve and stabilise your vision. In the 3-stage procedure, these 3 treatments are combined:

1 Intrastromal Corneal Rings are small, curved devices that are inserted into your cornea with the help of a femtosecond laser. They help flatten the curve of your cornea and improve vision.

2 After this cross-linking is used to strengthen your cornea in this position. This can be combined with a laser (PRK) to remove some of the small imperfections.

3 Lastly a secondary intra-ocular lens can be inserted to correct the remaining refractive error. This works like a contact lens that is implanted into the eye.

“Nothing worth having was ever achieved without effort.” Theodore Roosevelt

I need a corneal transplant. What are my options?

A corneal transplant is advised in advanced keratoconus when you are not a candidate for one of the less invasive procedures mentioned above. This surgery replaces all or part of your diseased cornea with healthy donor cornea tissue. Many keratoconus patients still have a healthy innermost layer of tissue. During Deep Anterior Lamellar Keratectomy (DALK) only the outer layer of the central part of the cornea is replaced with donor cornea. With this procedure there is virtually no graft rejection. During Penetrating Keratoplasty (PKP) the full thickness of the central part of the cornea is replaced with donor cornea and sutured in place.

Corneal transplant is an art, it is a journey where your heart will be equally exercised with your head. The entire journey takes about 24 months and requires patience and a positive attitude. The first 12 months of the journey includes removing sutures one by one while the cornea is healing. Shaping the cornea by releasing tension where necessary. Unfortunately, it is not possible to give you a perfectly shaped cornea and you will still have a refractive error. After this you may choose to use glasses or contact lenses and not have any additional procedures. Three months after the last suture was removed you may choose to continue with the journey and consider other options to reduce your dependance on corrective lenses.

A topography guided laser ablation (PRK) can be used to improve the regularity of the surface of your cornea. This will improve your vision with glasses. The next step is to implant a secondary lens. This is almost like a contact lens that is implanted into the eye. This should give you clear vision without glasses. The key to corneal transplant surgery is not only the ability to wait for your results, but the ability to keep a positive attitude while waiting.