What is DSAEK?
Descemet’s Stripping Automated Endothelial Keratoplasty (DSAEK)
The cornea, the transparent front “window of the eye”, is responsible for about two thirds of the focusing power of the eye. The cornea’s refractive power is actually greater than that of the eye’s lens.
The cornea receives its nutrients through the tear film. A normal, healthy cornea should be transparent, thus devoid of blood vessels and opacities. Corneal tissue can become damaged through disease or trauma. This damage can cause scar tissue and opacities in the normally-clear cornea, resulting in a reduction in visual acuity.
If the cornea develops visually significant opacities or irregularities, a corneal transplant, or DSAEK procedure can be performed.
What is DSAEK
Descemet’s stripping automated endothelial keratoplasty (DSAEK) involves surgically replacing diseased cornea tissue with donor cornea tissue. Instead of the entire cornea being removed and replaced, only the damaged layer of tissue is replaced, making DSAEK a much less invasive option than the traditional method of total corneal transplantation.
This less invasive procedure leads to rapid recoveries and reduces the risks of sight threatening complications like hemorrhaging, infection and wound rupture.
Who is a candidate?
DSAEK is a preferred surgical procedure over corneal transplant, but it is not for everyone. Only those corneas with defects and damage limited to the inner cornea layer (endothelium) are candidates for DSAEK. Eyes with corneal scars are not good candidates for DSAEK and will be considered for full corneal transplant surgery.
A common disease that can cause damage to this inner layer of the cornea is Fuchs’ Corneal Dystrophy. This inherited eye disease causes the cornea to swell, opacify and distort vision.
The surgical procedure
DSAEK is an outpatient procedure. No hospitalization is required. The entire surgery, including prepping the eye, usually takes between 45 and 60 minutes.
After the eye is cleaned and prepared with a sterile drape, a small incision is made at the edge of the cornea. Through this tiny incision, the diseased inner layer of cornea is peeled away and removed. The donor cornea’s inner layer is separated from the other layers with a precision machine called a microkeratome. This ultra-thin “button” of cornea is then carefully folded and inserted into the eye through the incision and attached to the back, inner “dome” of the cornea. The donor tissue is then held in place with an air bubble until it adheres to its new place in the patient,s eye, usually in about 24 hours.
The small incision is then secured with one small suture.
What are the differences between PK, DSAEK and DMEK?
(full thickness traditional cornea transplant)
(partial thickness posterior cornea transplant)
|DMEK (Single layer of cells and supporting membrane)|
|Typical time for visual improvement||6-12 months||4-6 weeks||2 weeks|
|Rejection rates at 2 years||17%||9%||.7%|
|Visits for suture adjustment||6-12 visits||2-3 visits||1|
|Time of surgery||45-60 mins.||45-60 mins.||15-20 min.|
|Wound size||7.5 mm diameter circle||3.2 mm linear||Less than 2.4 mm|
|Graft thickness||550 microns||60-100 microns||10 microns|
|Contact lens required||Rigid gas permeable (often)||Not required||None|
|Induced astigmatism||High regular and Irregular astigmatism possible||Minimal to no induced astigmatism||None|
|Indications for surgery||Cornea scar, keratoconus, pellucid marginal degeneration, corneal ulcer||Fuch’s endothelial dystrophy, cornea edema, pseudophakic bullous keratopathy||Fuch’s endothelial dystrophy, cornea edema, pseudophakic bullous keratopathy|
Explore the 3 types of corneal transplants
- Penetrating keratoplasty (PK)
- Descemet’s Stripping Automated Endothelial Keratoplasty (DSAEK)
- Descemet’s Membrane Endothelial Keratoplasty (DMEK)