PDEK
Partial thickness corneal transplantation is what Pre Descemet’s Endothelial Keratoplasty is all about.
Cataract:
What is Cataract?
The sick endothelial cells are removed from the patient’s eye, and a new layer of endothelial cells, obtained from the donated eye, are selectively transplanted into the patient’s eye in order to replace the diseased cells. Endothelial cells are healthy cells that line the back of the cornea and pump fluid away from the eye to prevent the cornea from expanding. These cells can be found in the endothelium. The typical range for the endothelial cell count is between 2,000 and 3,000 cells per mm2. When the number of cells in the cornea drops below 500 cells/mm2, corneal decompensation takes place. This causes the clarity of the cornea to diminish, which ultimately leads to foggy vision.
What happens during a penetrating keratoplasty procedure?
Penetrating keratoplasty is typically carried out with the patient only undergoing local anaesthesia. In this procedure, the patient’s endothelium is removed through a tiny incision (opening) in the cornea, and a disc of donor endothelium is put into the eye, where it is held in place by an air bubble.
Halos circling lights.
A small number of sutures may be placed during surgery and will be removed in a few of weeks (3-4) following the procedure. After a keratoplasty procedure is completed, the patient must lie completely flat for several hours to allow the graft time to adhere. Typically, the air bubble is absorbed in 48 hours, however this time frame can vary.
For what purposes is Penetrating Keratoplasty (PDEK) performed?
- Fuch’s endothelial dystrophy
- Pseudophakic bullous keratopathy
- Aphakic bullous keratopathy
- ICE syndrome
- Endothelial dysfunction secondary to glaucoma
What are the complications of Penetrating Keratoplasty (PDEK)?
- Graft detachment/ dislocation
- Recurrent epithelial erosions
- Cataract formation
- Glaucoma
- Graft rejection
- Graft failure
What benefits does it have over Keratoplasty that penetrates the cornea to its full thickness?
- Few sutures required as compared to penetrating keratoplasty.
- Suture induced astigmatism is avoided
- Suture related complications are avoided
- Greater stability
- Faster visual rehabilitation
- The graft can be obtained from any age group of the donated eyes
- Chances of rejection are less
What is corneal graft rejection?
Because the donor eye is genetically distinct from the patient’s body, the latter mounts an immune response to it. It’s termed corneal graft rejection when this happens.
What are the symptoms of corneal graft rejection?
The symptoms are: Redness, Sensitivity to light, Vision drop, Pain (RSVP). Along with sticky discharge and foreign body sensation.
Report to your Ophthalmologist as soon as possible if any of the above symptoms show up post-surgery.
How do I prevent graft rejection?
- In order to prevent rejection, a list of anti-rejection medications will be prescribed by your doctor, which should be used religiously.
- You should have an adequate supply of eyedropsat home so that a single dose is not missed.
- Do not stop any medication without consulting your Ophthalmologist.
- In case any of the above symptoms of rejection occur, meet your Ophthalmologist immediately. It can often be reversed if anti-rejection medications are started promptly. It should also be noted that rejection can occur at anytime in the years to come.
- Review regularly to check for vision, intraocular pressure, graft condition and retinal assessment.
What are the risk factors for rejection?
- Vascularisation over the cornea
- Pre-existing inflammation
- Corneal transplantdone more than 2 times
- Pre-existing glaucoma
-
What is graft failure?
Transplant failure occurs when anti-rejection medicine is not administered quickly enough or when the corneal graft rejection does not respond to the therapy. When a graft fails, it must be replaced. Furthermore, acute rejection, hyperacute rejection, and chronic rejection are the three forms of graft rejection.