All about Cornea Transplantation
How does our Eye Function?
The rays of light from an object strike the transparent cornea and bend (refract) to enter through the pupillary aperture and pass through the lens filter to form an image on the central part of the retina (macula) which acts as a film. This image signal is carried to the brain by the optic nerve which perceives it as the object known. This is how every component of the eye is important for visual perception.
What is Cornea Transplant?
If there is any kind of obstruction at the cornea affecting light rays from entering the eyes, we go ahead with a Cornea Transplant, wherein we remove the diseased cornea and replace it with a donor cornea obtained from a cadaver (within 6 hrs of death).
Why is Cornea Transplanted?
- Corneal Scar
- Corneal Ulcer
- Corneal Dystrophy
- Pseudophakic Bullous Keratopathy
- Severe Spheroidal Degeneration
- Advanced Keratoconus with apical scarring
- Trauma/Injury
Who can undergo Cornea Transplantation?
For a favourable outcome following are the prerequisites:
- Perception of light must be present
- Projection of rays accurate in all quadrants
- An intraocular pressure between 10-25 mm of Hg
- No Retinal or Choroidal detachment in the posterior segment
- Lids and Adnexa should be healthy
- Regular follow-up should be ensured
- Compliance with medication at given intervals to be strictly observed
- High risk of graft rejection/failure should be acceptable depending on host factors
How is Cornea Transplantation done?
What are the different types of Cornea Transplant?
- Full-thickness penetrating keratoplasty (PKP): Wherein all the layers of the diseased cornea are removed and replaced by full thickness donor corneal graft
- Deep Anterior Lamellar Keratoplasty (DALK): Wherein only the anterior layers of scarred or diseased cornea are replaced
- Descemet’s’ Membrane Endothelial Keratoplasty(DMEK): Where in only the innermost layer of the cornea which is affected in Fuch’s Dystrophy or PBK (Pseudophakic bullous Keratopathy) is replaced by the healthy layer of endothelial cells from the donor cornea.