This article is more than 5 years old. Information may no longer be current.
Surgeons detail steps for simple limbal epithelial transplantation
The technique can be used when there is limbal stem cell deficiency in one eye and healthy limbus in the other eye.
Click Here to Manage Email Alerts
In 1964, Jose Barraquer described a surgical technique for limbal stem cell deficiency, or LSCD. The paramount finding of extensive LSCD is conjunctival transgression across the corneal-conjunctival border and the limbus and onto the cornea, resulting in vascularization, chronic inflammation, persistent epithelial defects and recurrent erosions, which uninterrupted can progress to corneal opacity and transform to a skin-like corneal surface with corneal blindness. These border “policemen” between the corneal and conjunctival territories are largely accepted as the limbal stem cells that are believed to be housed within the radial fibrovascular ridges, the limbal palisades of Vogt.
With all the global research in this field, there is no definite marker at the present time for limbal stem cells. Compromise of limbal stem cells up to a certain extent, namely, partial or sectoral LSCD, can be corrected by the remaining stem cells. However, more extensive or total LSCD results in the inevitable transformation of the clear cornea toward an opaque cornea and potential loss of vision.
Management strategies depend on the following key questions:
1. Unilateral or bilateral LSCD?
2. Extent of damage — mild or extensive?
3. Is there active inflammation, or is the eye quiescent?
4. Is there enough tear function, and is lid function normal or abnormal?
Ocular surface stabilization is a must before undertaking surgical intervention for LSCD. Transplanted tissue may be conjunctival limbal autograft, keratolimbal or mucosal; it may be autologous in unilateral LSCD, and allogenic, namely, cadaveric or living related, in bilateral LSCD or cell culture-assisted techniques. Partial LSCD in a quiet eye with good tear and normal lid functions may be successfully treated with only conjunctival scraping and amniotic membrane transplantation. For extensive unilateral LSCD, autologous keratolimbal grafts from the opposite healthy eye, without systemic immunosuppression, and for more extensive bilateral LSCD, allogenic keratolimbal grafts, with systemic immunosuppression, are usually the treatment approaches. Primary penetrating keratoplasty will usually fail in LSCD. Tissue-sparing surgical techniques involve ex vivo or in vivo limbal stem cell expansion procedures.
In this column, Drs. Palioura, Atallah, Karp and Amescua describe how they perform the newly reported simple limbal epithelial transplantation (SLET) technique for unilateral LSCD. This is an in vivo limbal stem cell expansion technique.
Thomas “TJ” John, MD
OSN Surgical Maneuvers Editor
A thorough slit lamp examination must be performed preoperatively in both eyes to document the presence of LSCD in one eye and healthy limbus in the other eye. It is important to ensure the presence of a healthy donor eye, especially in patients with a history of chemical burns. It is not uncommon that such patients may have had injury in both eyes but only the severely affected eye manifests signs of LSCD. Patients with a history of autoimmune or inflammatory cicatricial conjunctival disease should not undergo this procedure even if the disease appears “unilateral” or “quiet” on clinical exam. In our experience, another excellent application of the SLET technique is in patients who develop LSCD after surgical or medical treatment of ocular surface neoplasias.
Figure 1. Retrieving the SLET transplant from the healthy donor eye. A subconjunctival dissection is performed 1 mm into the clear cornea, and the limbal tissue is excised.
Figure 2. The area of the limbal biopsy in the healthy donor eye is covered with the adjacent conjunctiva using fibrin glue.
Figure 3. The contralateral recipient eye with limbal stem cell deficiency and visible conjunctivalization and vascularization of the cornea.
Figure 4. A 360° peritomy is performed in the recipient eye.
Images: Amescua G
Figure 5. A superficial keratectomy is performed to remove the fibrovascular pannus covering the recipient cornea.
Figure 6. An amniotic membrane graft is placed over the bare ocular surface and secured in place with fibrin glue.
Figure 7. The donor SLET transplant is cut into 8 to 10 pieces, which are distributed over the recipient corneal surface, sparing the visual axis.
Figure 8. The SLET transplants are secured in place with fibrin glue.
Operative technique
The procedure can be performed under monitored anesthesia care with local anesthesia using a peribulbar or retrobulbar injection of a 1:1 mixture of 2% lidocaine and 0.75% bupivacaine. Both eyes are prepped in a sterile ophthalmic fashion with 5% povidone-iodine. Attention is first directed to the donor eye in order to excise the limbal tissue to be transplanted. A 2- to 3-mm area (1 clock hour) is marked with calipers in the superior limbus of the donor eye, and the conjunctiva is incised 2 mm posterior to the limbus. A subconjunctival dissection is carried out up to the limbus using a crescent blade. The dissection then proceeds into the cornea for about 1 mm (Figure 1). The tissue is excised using Vannas scissors or a No. 15 blade, placed in balanced saline solution and set aside. In order to avoid damage to the limbal epithelial stem cells, the tissue is always grasped from the conjunctival side. The area of the limbal biopsy is covered with the adjacent conjunctiva using fibrin glue (Tisseel, Baxter) (Figure 2).
Figure 9. A second piece of amniotic membrane is placed on top of the SLET transplants.
Figure 10. A 10-0 nylon limbal suture is applied in a purse-string fashion to secure the second piece of amniotic membrane.
We can now proceed to the recipient eye (Figure 3). A 360° peritomy is performed using 0.12 forceps and Westcott scissors (Figure 4). The fibrovascular pannus covering the cornea is removed using a crescent blade (Figure 5). Following the superficial keratectomy, gentle cautery is applied to any bleeding vessels, and the corneal surface is smoothened using a diamond burr. Amniotic membrane (AmnioGraft, Bio-Tissue) is then used to cover the entire surface (Figure 6). In particular, the amniotic membrane is thawed, cut to size and peeled from the nitrocellulose paper. It is placed on the ocular surface with the stromal side facing down and secured in place with Tisseel glue. We first apply the fibrinogen component of the glue and then the thrombin, although they can also be applied together. Using a muscle hook, we smoothen the amniotic membrane, and we tuck its edges under the surrounding conjunctiva. Any excess membrane and glue are trimmed.
The donor tissue is then brought into the operating field, it is gently held with non-toothed forceps, and it is cut into 8 to 10 pieces using Vannas scissors (Figure 7). These small limbal transplants are placed on the amniotic membrane in a circular fashion, taking care to avoid the visual axis. A couple of drops of fibrin glue are used to secure the transplants in place (Figure 8). In the original technique described by Sangwan and colleagues, a bandage contact lens is placed at this point and the recipient eye is patched overnight. In order to make sure that the transplants stay in place and are not accidentally dislodged, we have modified this technique. Thus, after the transplants are placed on the amniotic membrane, we apply a couple of drops of fibrin glue and then place another piece of amniotic membrane on top (Figure 9). The membrane is again placed stromal side down. It is further secured with a 10-0 nylon limbal suture, which is applied in a purse-string fashion around the limbus (Figure 10). A bandage contact lens is then placed on top of this second membrane. The recipient eye receives antibiotic and steroid drops and is patched and shielded overnight. Antibiotic/steroid ointment is placed on the donor eye, which is patched and shielded for a few hours. The patch is removed before discharge from the hospital.
Postoperative care
In the recipient eye, the patient uses topical steroid drops six times a day for the first week and starts a weekly taper over the next 5 weeks. Both eyes receive a topical antibiotic drop four times a day for the first week. The bandage contact lens is removed at postoperative week 1.
- References:
- Amescua G, et al. Am J Ophthalmol. 2014;doi:10.1016/j.ajo.2014.06.002.
- Atallah MR, et al. Clin Ophthalmol. 2016;doi:10.2147/OPTH.S83676.
- Basu S, et al. Ophthalmology. 2016;doi:10.1016/j.ophtha.2015.12.042.
- Holland EJ. Cornea. 2015;doi:10.1097/ICO.0000000000000534.
- Khan-Farooqi H, et al. Semin Ophthalmol. 2016;doi:10.3109/08820538.2015.1114862.
- Sangwan VS, et al. Br J Ophthalmol. 2012;doi:10.1136/bjophthalmol-2011-301164.
- For more information:
- Guillermo Amescua, MD, can be reached at Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, 900 NW 17th St., Miami, FL 33136; email: gamescua@med.miami.edu.
- Edited by Thomas “TJ” John, MD, a clinical associate professor at Loyola University at Chicago and in private practice in Oak Brook, Tinley Park and Oak Lawn, Ill. He can be reached at email: tjcornea@gmail.com.
Disclosures: Palioura, Atallah, Karp, Amescua and John report no relevant financial disclosures.