KERATOCONUS


Keratoconus is corneal ectasia of disputed etiology which leads to cornea thinning and consequent deformation into a conic shape, which triggers the occurrence of high regular astigmatism and consequent reduction of visual acuity.
Keratoconus is always bilateral and asymmetrical, and manifests during adolescence.

SYMPTOMS

Keratoconus may be hard to detect and, habitually, emerges slowly. However, in some cases, keratoconus can progress rapidly. As the cornea shape becomes increasingly irregular, there is gradual vision loss. Glare and photophobia might occur as well.

Keratoconus patients tend to have their lens prescriptions renewed each time they visit their ophthalmologist.

Quite frequently keratoconus diagnosis comes late if ophthalmologists are not familiar with such cases and do not identify the early stages of the disease.

CAUSES

Keratoconus is a progressive degenerative condition and can occur at any age in the life of a person.

Most of patients are diagnosed early during adolescence, when the disease progresses more aggressively.

Major risk factors are heredity and allergic conjunctivitis normally associated with constant eye rubbing.

Treatments

FERRARA RING™

In the early stages of keratoconus, contact lens fitting or glasses can help patients. As the disease progresses, cornea thinning increases the irregularity of its shape and hinder the improvement once provided by glasses or lenses.

The Ferrara Ring® is a surgical alternative which delays or eliminates the need for corneal transplantation.

Keratoconus may be hard to detect and, habitually, emerges slowly. However, in some cases, keratoconus can progress rapidly. As the cornea shape becomes increasingly irregular, there is gradual vision loss. Glare and photophobia might occur as well.

Keratoconus patients tend to have their lens prescriptions renewed each time they visit their ophthalmologist. Quite frequently keratoconus diagnosis comes late if ophthalmologists are not familiar with such cases and do not identify the early stages of the disease.

Keratoconus is a progressive degenerative condition and can occur at any age in the life of a person. Most of patients are diagnosed early during adolescence, when the disease progresses more aggressively.

Major risk factors are heredity and allergic conjunctivitis normally associated with constant eye rubbing.

SCLERAL FITTING LENSES

Scleral lenses are larger-diameter contact lenses, suitable for irregular corneas, and can help keratoconus patients.
However, scleral lenses do not treat keratoconus and if its progression is observed, a Ferrara RingTM implant can be recommended.

CROSSLINKING

Crosslinking emerged as an approach in the treatment of keratoconus around 10 years ago.
Riboflavin application associated to ultra-violet light in controlled intensity strengthens corneal collagen structures making the cornea more rigid and resistant to deformation.
In advanced cases of keratoconus, a Ferrara RingTM implant is recommended to correct corneal irregularity and, in case of disease progression, Crosslinking application may be recommended.

CORNEA TRANSPLANT

A cornea transplant is the last resort for treating keratoconus.
Even after a transplant, a Ferrara RingTM implant might be made necessary if post-transplant/post-keratoplasty irregular astigmatism is significant.
Currently, 320°arc length segmentsmay be indicated for advanced cases of keratoconus and postpone the need for cornea transplant.

Frequently Asked Questions

95% of patients who have undergone Ferrara RingTM implantation do not need a cornea transplant.

In some cases, scleral lens fitting is made necessary. In most cases, though, glasses or gelatinous lenses will suffice.

No. This surgical technique, when properly performed, is always beneficial to the cornea.

Complications related to the surgical technique such as implants superficiality may result in spontaneous ring extrusion.Improper segment positioning may cause astigmatism but this is rarely observed. Complications related to inadequate post-operative care may occur when patients rub their eyes which could cause segment displacement, spontaneous extrusion or infection.

In general, all complications are reversible with the removal or repositioning of Ferrara RingTM segments.

Surgery complications rarely occur. The segment removal rate is lower than 4% after the procedure.Infections can lead to more severe complications and may result in the need for a cornea transplant. Fortunately, infections have been observed in less than 0.08% of the cases.

A cornea transplant requires a long period of recovery, usually around 12-month long. This type of transplant also presents risk of rejection and does not prevent keratoconus from reemerging. In most cases, wearing glasses or contact lenses is made necessary, and the patient can furthermore have to resort to a Ferrara RingTM implant in order to correct a high degree of irregular astigmatism which may result from an Improper or poor transplant recovery.

  • Patient’s quick recovery
  • Compatibility between Ring material and cornea tissue;
  • If contact lenses are needed, adaptationis easy;
  • Reversibility;
  • A Ferrara RingTM implant delays or ceases the progression of the disease for an indefinite period of time.

The success rate depends on how severe the degree of keratoconus is. The sooner the surgery is performed, the higher the chances of success are. For early interventions, the success rate is above 95% of cases.

Ferrara ringTM implants flatten and regularize corneal surface thus correcting deformities such as myopia and astigmatism. Ferrara rings can also be used complementarily to laser or Phakic lenses to correct cases of high myopia.

Vision recovery is quick. The day after surgery, the patient’s vision already shows improvement and stabilizes after three months. During this period fluctuations in vision quality may occur. While vision may be acute in the morning, it can otherwise present with higher blurring along the day. Prescription of glasses or contact lenses may be needed for complete correction. Meanwhile, vision can become acute or slightly blurred.

There are barely any risks related toFerrara RingTM implant surgeries.As with any other surgery, infections may occur. In such cases, Ferrara RingTM segments must be removed. Complications are minimal and, most importantly, reversible. This means that segments can be removed and the cornea returns to its original shape. There is no risk of orthosis rejection.

Surgical procedures are performed under ambulatory care and full asepsis. Local anesthesia is applied by means of eye drops. Asepsis includes the region of eyes, nose and eyelids. After surgery, a healing lens or gauze is used to prevent contact with infectious agents. The procedure is painless and performed within about 10 minutes. The use of antibiotic and anti-inflammatory eye drops makes the postoperative period safer and more comfortable. The day after surgery, patients can resume their intellectual activities.

No. The main objective of a Ferrana RingTM implant is to achieve visual rehabilitation. A Ferrana RingTM implant can delay keratoconus progression preventing the need for a cornea transplant for indefinite time.

Most of the patients do not present complaints related to night vision. Corrective lenses may be necessary after a Ferrana RingTM implant to correct residual ametropia.