Three types of corneal transplants

The cornea, the transparent front “window of the eye”, is responsible for about two thirds of the focusing power of the eye.

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 procedure can be performed. A corneal transplant involves replacing a diseased or scarred cornea with a new cornea or specific corneal layers tissue.

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 improvement6-12 months4-6 weeks2 weeks
Rejection rates at 2 years17%9%.7%
Visits for suture adjustment6-12 visits2-3 visits1
Time of surgery45-60 mins.45-60 mins.15-20 min.
Wound size7.5 mm diameter circle3.2 mm linearLess than 2.4 mm
Graft thickness550 microns60-100 microns10 microns
Contact lens requiredRigid gas permeable (often)Not requiredNone
Induced astigmatismHigh regular and Irregular astigmatism possibleMinimal to no induced astigmatismNone
Indications for surgeryCornea scar, keratoconus, pellucid marginal degeneration, corneal ulcerFuch’s endothelial dystrophy, cornea edema, pseudophakic bullous keratopathyFuch’s endothelial dystrophy, cornea edema, pseudophakic bullous keratopathy

Layers of the cornea

Layers of the cornea

Corneal layers diagram