Of all of the transplant surgeries performed today, including heart, lung and kidney transplant, corneal transplant is the most common and successful. Our corneal specialist, Dr. John Bokosky, has been performing corneal transplant surgery for two decades. He is at the forefront of advances in technique and technology that help to make corneal transplant safer, with better visual outcomes.
When Is Corneal Transplant Needed?
In cases of damaged or diseased corneas that impair vision so severely that they affect daily functioning, transplant may be the only solution for vision loss. During a transplant procedure, the damaged or diseased portion of the cornea is removed and replaced with healthy tissue from a donor.
Corneal transplant may be necessary in cases of the following:
- Severe keratoconus
- Fuchs’ Dystrophy
- Scarring from an infection or injury
- Complications from LASIK, cataract surgery, corneal surgery or another surgery that damaged the cornea
Our practice works closely with the San Diego Eye Bank (where Dr. Bokosky serves as medical director) to safely obtain healthy donor tissue. The tissue is required to both pass extensive testing for transmissible diseases and to meet other safety requirements.
Full Thickness Corneal Transplant
Penetrating keratoplasty (PKP) replaces the entire thickness of the cornea with clear donor tissue. During the surgery, the doctor removes a button-sized disk of tissue from the five layers of the cornea: the epithelium, Bowman’s layer, the stroma, Descemet’s membrane and the endothelium. The donor cornea is precisely cut to fit into the opening where the diseased/damaged tissue was removed. The doctor then uses very fine sutures to stitch the new cornea into place.
Partial Thickness Corneal Transplant
Transplanting the entire thickness of the cornea is not always the most suitable approach to treatment. In cases where the front and middle layers of the cornea are damaged or diseased, only those layers may be removed and replaced, while the back layers are kept intact. For example, a deep anterior lamellar transplant (DALK) procedure removes the epithelium, Bowman’s layer and part of the stroma, leaving Descemet’s membrane and the endothelium intact.
In other cases, the innermost layer of the cornea is removed and replaced while the front and middle layers are left untouched. This approach is known as endothelial keratoplasty (EK).
There are a few types of EK surgery: Descemet’s Stripping (Automated) Endothelial Keratoplasty, or DSEAK or DSEK, and Descemet’s Membrane Endothelial Keratoplasty (DMEK). During these surgeries, the damaged cells of the Descemet’s membrane layer are removed and replaced, and the rest of the cornea is left intact.
Partial thickness corneal transplant has been shown to produce great visual outcomes and reduce some of the risks associated with full thickness corneal transplant.
Boston Keratoprosthesis (KPro)
In cases where a standard corneal transplant has failed or, because of certain factors, is unlikely to succeed, the Boston Keratoprosthesis (KPro) may be a more suitable option. This artificial cornea device is used in conditions that are the most difficult to treat.
If you would like to discuss corneal transplant surgery in person with Dr. Bokosky, please contact Eye Care of San Diego and request an appointment.