Keratoconus is a corneal ectatic disease characterized by non-inflammatory progressive thinning of unknown cause in which the cornea assumes a conical shape. This cone shape deflects light as it enters the eye on its way to the light-sensitive retina, causing distorted vision. Keratoconus can occur in one or both eyes and often begins during a person’s teens or early 20s.
Keratoconus Symptoms and Signs
Keratoconus can be difficult to detect, because it usually develops slowly. However, in some cases, keratoconus may proceed rapidly. As the cornea becomes more irregular in shape, it causes progressive nearsightedness and irregular astigmatism to develop, creating additional problems with distorted and blurred vision. Glare and light sensitivity also may occur.
Often, keratoconic patients experience changes in their eyeglass prescription every time they visit their eye care practitioner. It’s not unusual to have a delayed diagnosis of keratoconus, if the practitioner is unfamiliar with the early-stage symptoms of the disease.
Who suffers from Keratoconus
Keratoconus is a degenerative corneal disorder found in any age. Most patients are diagnosed during the teenage years when the disease tends to evolve more quickly. The main risk factors for the disease are: 1) Genetic; 2) UV exposure; 3) Allergic conjunctivitis – usually related to eye rubbing.
In the mildest form of keratoconus, eyeglasses or soft contact lenses may help. As the disease progresses, the cornea thins and becomes increasingly more irregular in shape rendering glasses and soft contacts ineffective at providing adequate vision correction.
The Ferrara Ring is a surgical alternative to delay, if not eliminate, the need of lamellar or penetrating keratoplasty.
When do you recover the eyesight after surgery?
Eyesight recovery is fast. The day after the surgery vision starts to get better and stabilizes after three months. During this first period of time, fluctuations in the sight happen. In the morning the patient sees well, but during the course of the day the sight may get a bit blurry. Since patients don’t undergo plastic surgery, prescription glasses or contact lenses could be needed to complete the correction. Meanwhile, eyesight can be good or slightly blurry.
What are the risks of the surgery?
There are almost no risks. As with any other surgery, there may be an infection. In this case, the ring shall be removed. There is no risk of rejection from the body. The surgery does not damage or prevent a cornea transplant. The complications are minimal and, most important, reversible. This means the ring can be removed and the cornea recovers its original size.
How does the surgery happen?
The surgical procedure is done together with all kinds of asepsic care. The anesthesia is done externally, with anesthetic eye drops. The asepsis includes the area of the eyes, nose and forehead. After surgery, the face is covered by sterile surgical gauze to prevent infectivity. The procedure is completely painless and it takes only 10 minutes. After the operation, a therapeutic contact lens is applied as a curative. The use of antibiotic eye drops and anti-inflammatory allow a more conformable and safe postoperative period. After 3 days the patient can go back to his/hers usual activities.
Is the Ferrara Ring a substitute for a corneal transplant?
No. The basic goal of the Ferrara Ring is the sight rehabilitation. Meanwhile, the ring implant may delay the evolution of the disease, avoiding the need of a cornea transplant for an undetermined period of time.
Is there a risk of blurry sight after the surgery?
Most of the patients do not complaint of night vision issues. Tests on blindness and sensitivity of the eyes do not report such problem.
How many people need prescription glasses or contact lenses to achieve the complete vision correction?
Close to 30% of the patients who undergo surgery need contact lenses and 40% need prescription glasses.
What is the success rate of this operation with surgeons other than Dr Ferrara?
There are close to 300 surgeons who carry out this type of surgery and all of them report similar results.
Do the changes on the curve of the cornea after the ring implant prevent or cause difficulties in the use of contact lenses?
Since the cornea flattens after surgery, both in the centre and the periphery, the adaptation to contact lenses is better than before the operation.
Does this type of surgery cause any side effect in the long run?
No. The technique, when carried out properly, is always beneficial to the cornea.
When complications happen, what are the consequences for the patient?
Since the Ferrara Ring is a superficial implant, it can be removed and re-implanted. If the surgical procedure is not carried out properly, the operation can be repeated.
How often complications happen?
Complications are hardly ever seen. The index of ring removals is of as little as 4% after this type of surgery. An infection is the most serious complication the patient may face, and it may result on a cornea transplant. Fortunately, is seen as little as 0.08% of the times.
What other complications may the patient face?
Surgical technique related complications such as a superficial implant that could originate a self-extraction of the ring or a bad placement of the segments that could cause astigmatism are rarely seen. Patient behavior related complications might happen when rubbing the eyes, since the segments of the ring could move, self-extract or cause an infection.
Which surgery gives a better result, the ring implant or the cornea transplant?
The cornea transplant requires a long period of recovery, around 12 months. Also, the body may reject it at any moment, it doesn’t guarantee the keratocone cure and most of the times wants sight correction with prescription glasses or contact lenses, and the patient may even need a ring implant to correct the high degree of irregular astigmatism after a bad healing.
Which are the advantages and disadvantages of the ring implant in contrast with the cornea transplant?
The advantages of ring are:
• Fast recovery of the sight.
• The body does not reject the implant
• If contact lenses are necessary, they adapt easily to the eye
• The ring delays or even stops the disease for an undetermined period of time
What is the success rate for this surgical procedure? Is it different for every patient?
The success rate depends on the severity of the keracotone. The earlier the surgical procedure takes place, the more chances of success. Operations in the early stages are successful at a 95% rate.
Is the Ferrara ring also recommended for myopia?
The implant of the intra-corneal ring flattens and regularizes the cornea. Therefore, it corrects deformities such as myopia or astigmatism. The ring can also be used as complementary to techniques such as laser or phakic lenses, to correct high degrees of myopia.