Anterieure lamellaire keratoplastiek

Anterior lamellar keratoplasty is often used as a treatment for indications like keratoconus and other types of corneal ectasia, stromal corneal dystrophies and corneal scarring.

Bowman layer transplantation

The NIIOS, which the Melles Cornea Clinic is a part of, developed the “Bowman layer transplant” several years ago. A thin layer of a donor cornea (the Bowman layer) is attached to the patient’s stroma during this operation. No tissue is removed during this process.

The Bowman layer transplant consists of the following surgical steps: The top layer of the cornea (the epithelium) is first scraped away. The Bowman layer graft is then placed on the cornea, unfolded and carefully smoothed. A bandage lens is then placed on the eye. The epithelium will then grow back over the Bowman layer graft under the bandage lens. After a few weeks, you will no longer need the bandage lens.

This new technique may be indicated for keratoconus, map-dot-fingerprint dystrophy, Salzmann’s nodular degeneration and superficial corneal scarring.

Deep anterior lamellar keratoplasty (DALK)

This type of cornea transplant can be performed if the defect only affects the anterior part of the cornea. This operation will only replace that section of the cornea. The posterior, healthy section will remain intact. Possible indications are keratoconus and other types of corneal ectasia, stromal corneal dystrophies and corneal scarring.

The DALK operation consists of the following surgical steps: A small opening is created adjacent to the cornea, and small spatulas are inserted deep into the cornea to help generate a splice layer on the border with the Descemet membrane. A trepan (a small corer) is then used to create a circular opening in the middle (this opening reaches the Descemet membrane). Any edges which are still attached are then gently cut loose. The DALK graft is then inserted and sutured into place.

Just like in penetrating keratoplasty, a small circular disc is removed from the cornea. However, in DALK, this is limited to the anterior section. The donor corneal disc is then attached to the patient’s cornea.

As the surrounding cornea supports the donor tissue, this type of operation yields a more stable wound than the one created following penetrating keratoplasty. This results in a quicker recovery, and the stitches can usually be removed earlier than following penetrating keratoplasty. Definitive vision can be achieved following a period of six months. Many patients need contact lenses, in addition to glasses, to be able to see well.