DALK Corneal Transplant:

Targetted Corneal Layer Replacement

DALK surgery is an advanced corneal transplant procedure that removes only the damaged upper to mid portions of your cornea, leaving healthy underlying tissue intact.  As a result, it offers the following benefits:

• improved corneal strength because only a partial thickness has been replaced, leaving the innermost cornea secure
• faster recovery and return to work/ school because of improved corneal strength and earlier removal of sutures
• better visual acuity with less residual refractive error because the "seam" from the transplant is more superficial
• results in almost no risk of rejection as the lining of the cornea that is the area most responsible for rejection remains undisturbed and is your own tissue

Your procedure will be performed at Rocky Mountain Surgery Centre, Dr. Demong's private ambulatory surgical facility adjacent to his Calgary office.  Although you are awake during your procedure, local anesthetic (freezing) causes inability to move the eye and loss of sensation so there is no discomfort at the time of treatment.  Our nursing staff describe the anticipated process and answer your questions as they prepare you and make sure you are positioned comfortably.  It is important for you to remain still throughout the 75 - 90 minute procedure.

You will be covered with sterile drapes that are tented so you can breathe comfortably throughout the procedure.  Dr. Demong uses a microscope to perform the surgery so you'll notice a very bright light but all other movements will appear blurry.

Using a delicate instrument called a trephine, Dr. Demong penetrates the upper layers of the cornea in a circular fashion.  Then he injects an air bubble under the circumscribed area to gently separate the affected layers from the underlying healthy layers.  Once the dome is loosened and adhering tissue has been released, he carefully peels the dome away exposing the deep healthy layers of the cornea.  A second air bubble may be injected  and a second delicate peel may be necessary if corneal disease/ scarring extends deeper into the cornea.  This part of the procedure requires exquisite control.

Donor corneal tissue of a same circumference and thickness is then placed over the healthy tissue and is  sutured into place with multiple ultra-fine sutures.  The sutures will be removed at intervals throughout your recovery.

Following surgery, Dr. Demong places a pressure patch over the operative eye.  You should not disturb the patch for the first evening as there are no drops to take until the next day.  Eye drops will be introduced when you have your first follow up examination the day after surgery.  You will need a driver to take you home after the surgery and return with you to the office the next day.

When the freezing wears off, you may experience mild to moderate discomfort best controlled with the analgesic Dr. Demong prescribes or recommends.  Your cornea will be somewhat densensitized following surgery but within a few days, you may note mild to moderate irritation from the sutures, diminishing as you recover.  Using artificial tear drops following instillation of your medicated drops may ease the sensation.

Substantial improvement in vision is usually attained within 2 - 3 weeks of surgery, depending upon the condition of your eye and your individual recovery, but best vision may not be achieved until all sutures are removed.  Vision will change each time sutures are removed.

Following DALK, the risk of graft rejection is extremely unlikely but Dr. Demong will monitor you closely for other problems such as infection, bleeding and increased eye pressure.  Because medications minimize the risk of these adverse reactions, it is essential to follow all instructions precisely.