The partial corneal transplant procedure is known as one of the common types of corneal transplantation surgeries, and it is considered the final therapeutic option for advanced corneal problems. When the corneal tissues become damaged and the patient develops irreversible visual distortions, this procedure becomes the best choice. Therefore, today we will introduce you, from Dr. Sherif Momtaz Hegazy’s Center, to the concept of partial corneal transplantation, its importance, its steps, and the difference between it and full-thickness corneal transplantation. So, if you are preparing for this surgery or in need of it, there is a lot of essential information that is important for you.
Partial Corneal Transplant Surgery
The concept of partial or full corneal transplantation is based on treating highly advanced corneal problems that cannot be managed with conventional methods.
In such cases, medical lenses, eyeglasses, or even corneal cross-linking with riboflavin and corneal ring implantation are no longer effective because the condition is more severe and the damage is very extensive.
From an anatomical perspective, the eye consists of five tissue and membrane layers. If some of these layers are damaged due to disease, external trauma, or other causes, there is no need to replace the entire cornea with a new one; replacing only the damaged layers is sufficient.
This surgery specifically involves removing the damaged tissue of the cornea—usually up to a depth of 8 mm—and replacing it with healthy layers taken from a natural cornea obtained from a recently deceased donor under special criteria, or from the U.S. Eye Bank.
These donated corneas or their extracted layers are completely healthy and free from any problems. Even the donors themselves have never undergone eye surgery nor suffered from any ocular diseases.
Indications for Partial Corneal Transplant Surgery
The indications for partial corneal transplantation are not very different from those for full corneal transplantation. The conditions are quite similar, but the main difference lies in the depth of the problem and the extent of corneal damage. These include:
- Keratoconus in its mild and moderate stages, where the corneal protrusion is superficial rather than deep.
- Fuchs’ dystrophy, a hereditary disease in which fluid accumulates in the corneal layers.
- External corneal injuries and superficial wounds that do not reach the inner layers.
- Corneal scarring caused by bacterial or viral infections.
Types of Partial Corneal Transplant Surgery
Since the cornea consists of five layers, partial corneal transplantation is not limited to one method. It has several approaches depending on the surgical site, the target layers, and other details that can be clarified as follows:
• Endothelial Keratoplasty
In this type, the damaged tissues are the endothelial layers—located at the back of the cornea.
This surgery is also known as Descemet’s Stripping Endothelial Keratoplasty (DSEK).
The damaged posterior layers along with Descemet’s membrane are removed and replaced with new tissue from a donor.
Here, the surgeon deals with a relatively thick portion of the cornea—almost one-third of its depth.
• Endothelial Keratoplasty With Preservation of Descemet’s Membrane
This is one of the most complex types of partial corneal transplantation, dealing with extremely thin layers.
Only the endothelial layer is replaced while preserving Descemet’s membrane.
Since Descemet’s membrane is one of the thinnest membranes in the human body, performing the surgery without damaging it requires exceptional surgical expertise.
• Penetrating Keratoplasty
This is essentially the same as full corneal transplantation.
All damaged corneal layers are removed in a perfectly round disc shape from the corneal center, and the new cornea is placed into this circular opening. Surgical stitches are then applied to secure the graft and are later removed by the surgeon.
• Anterior Lamellar Keratoplasty
In this partial transplant technique, the endothelial layer is preserved because the damage does not reach it.
The surgeon determines the depth of damage to choose between two methods:
- Transplanting only the anterior layers while keeping the stroma intact.
- If damage extends to the stroma or deeper, the entire upper corneal layers are replaced with donor tissue. Some surgeons call this approach “layered corneal grafting.”
Immune Rejection in Corneal Transplant Surgery
The most important advantage of partial corneal transplantation is the greatly reduced risk of immune rejection.
Immune rejection is the greatest fear among patients undergoing corneal transplantation. If it occurs, the immune system attacks the transplanted cornea as if it were a foreign body, leading to severe symptoms such as:
- Intense eye redness
- Extreme light sensitivity
- Severe eye pain
- Rapidly worsening vision
Partial corneal transplantation reduces this risk significantly because the replaced layers are usually superficial and the surgical penetration is much less compared to full transplantation.
It is essential to clarify that immune rejection in corneal transplantation does not occur due to donor-recipient tissue mismatch, unlike popular belief. Corneal transplant surgeries do not require tissue matching, unlike organ transplants such as kidneys.
This factor greatly increases the availability of healthy corneas in the United States, eliminating the need for waiting lists since donor tissues are already readily available under regulated conditions.
Key Preoperative Steps Before Corneal Grafting
Dr. Sherif Momtaz Hegazy begins by performing a full eye examination to evaluate the extent of corneal damage and rule out other eye diseases.
Once partial corneal transplantation is confirmed as the optimal solution, the procedure, cost, and expected results are explained. Corneal measurements are taken precisely, and preoperative instructions are provided.
These steps include:
- Complete diagnostic testing to confirm the condition and rule out other eye problems.
- Exact corneal measurements to determine the appropriate graft size and dimensions.
- Reviewing chronic medications and discontinuing those that may affect surgery.
- Treating any active eye infection or condition that could hinder surgical success.
Steps of Partial Corneal Transplant Surgery
Once all tests are completed and suitability is confirmed, the surgery proceeds as follows:
- Local or general anesthesia.
- A special eyelid speculum is used to keep the eye open.
- A surgical blade or laser is used to remove the damaged corneal layer at a precise depth.
- The damaged tissue is removed completely.
- New donor tissue is inserted and positioned accurately.
- Surgical stitches are applied to fix the graft.
- A protective eye patch is placed after surgery.
Postoperative Instructions After Partial Corneal Transplant
These instructions, provided by Dr. Sherif Momtaz Hegazy, are essential for healing and include:
- Attending all follow-up appointments.
- Wearing eye shields at night and protective sunglasses during the day.
- Avoiding rubbing or touching the eye.
- Using prescribed eye drops and ointments regularly.
- Sleeping on your back as much as possible.
- Avoiding strenuous exercise, heavy lifting, or activities that increase eye pressure.
Recovery Time After Partial Corneal Transplant
Recovery time is much shorter than full corneal transplantation.
- Full transplant recovery: 12–18 months
- Partial transplant recovery: Around 4 months
During this time, the patient may experience mild blurry vision, discomfort, or redness—these symptoms gradually improve until full recovery.
Vision results vary widely between patients. Some recover vision quickly, others experience fluctuations for several months.
Advantages of Partial Corneal Transplantation
- Significant improvement in vision and daily functionality
- Safe corneal tissue renewal with better light focusing
- Long-lasting surgical results
- Minimal risk of immune rejection
Vision Correction After Partial Corneal Transplant
Some vision issues may appear after surgery, such as:
- Astigmatism due to tension from sutures
- Myopia or hyperopia as refractive errors
These are usually corrected through:
- Removing selective stitches
- Smoothing the corneal surface
- Laser vision correction (LASIK)
Best Ophthalmologist in Egypt
Despite being safer than full transplantation, partial corneal transplantation is not an easy procedure. It requires a highly skilled and experienced surgeon.
The best ophthalmologist in Egypt—and the Arab world—is Dr. Sherif Momtaz Hegazy, who holds the following positions:
- Fellow of Tübingen University, Germany
- Fellow of the Royal College of Surgeons, UK
- Member of the International Council of Ophthalmology
- Holder of a Master’s and Doctorate in Ophthalmology
- Professor at the Institute of Ophthalmic Research and Surgery
- Certified trainer at the Research Institute of Ophthalmology
- Scientific researcher with dozens of publications
- International lecturer in major medical conferences
- International examiner for the Royal College of Surgeons
These outstanding academic and professional achievements reflect a career of excellence. The surgical outcomes and patient care provided by Dr. Sherif Momtaz Hegazy are the greatest evidence of his expertise.
If you need partial or full corneal transplantation—or suffer from any eye problem—do not hesitate to book a consultation with Dr. Sherif Momtaz Hegazy to receive the best eye care.
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