- A video of this procedure is under the "Video" section of this site

Replacing the Endothelium Without Surface Corneal Incisions or Sutures: Deep Lamellar Endothelial Keratoplasty

Mark A. Terry, M.D.

Director, Corneal Services, Devers Eye Institute

Portland, Oregon

          Deep Lamellar Endothelial Keratoplasty (DLEK) is a surgical technique for the replacement of the corneal endothelium entirely through a limbal scleral tunnel incision. This technique obviates the need for any corneal incisions or sutures, and preserves the corneal surface from limbus to limbus. The inherent value of this technique is that it allows preservation of the normal corneal topography, faster and stronger wound healing, and the avoidance of suture related problems such as induced astigmatism, unpredictable corneal power, infection, ulceration, and suture-induced vascularization leading to graft rejection. The current challenges of this technique are the technical difficulty of the procedure and the challenges in consistently obtaining an optically pure interface.

          While the procedure is still in evolution, the current basic surgical steps are the following:

1.     A nine mm. scleral incision is made with a guarded diamond knife set at a depth of 0.35 mm, parallel to the limbus and 1 to 2 mm peripheral to it.

2.     Healon is injected through a stab incision at 10:00 o’clock into the Anterior Chamber to maintain it and modulate IOP.

3.     A mid to deep corneal pocket is formed from limbus to limbus using the Devers Dissectors (straight and curved).

4.     Healon is released from the AC through the stab incision and the 8.0 mm Terry Trephine is placed into the pocket, centered over the pupil and trephination of the posterior disc of the recipient is done until the AC is entered.

5.     The posterior disc trephination is completed with intracorneal, low profile, highly curved “Cindy” scissors and the disc is removed and measured for diameter and thickness.

6.     The Healon is completely aspirated from the AC and the interface with a Simcoe needle and replaced with BSS.

7.     The donor corneo-scleral tissue is placed in the Artificial Ant Chamber and the donor posterior button is prepared. An automated Microkeratome or a manual resection of the anterior donor stroma can be done.

8.     The donor tissue is mounted on a punch block, and a same size, 8.0 mm donor trephine is used to punch out the posterior donor disc.

9.     The donor disc is placed, endothelial side down, onto an Ousley insertion spatula which is previously coated with Healon.

10.  The anterior chamber of the recipient patient is filled with Air.

11.  The donor disc on the Ousley spatual is placed into the pocket, into the Ant Chamber and then lifted anteriorly into the posterior stromal recipient bed. It is held in position for 3 or 4 seconds and then the spatula is gently slid on the layer of Healon out of the eye, leaving the disc in place.

12.  Air is immediately injected into the AC to secure the graft.

13.  The donor disc position is gently adjusted for good coaptation of the edges and any air in the interface is removed with a Sinsky hook.

14.  The wound is closed with five to seven 10-0 nylon sutures, the conjunctival peritomy is closed with sutures.

15.  The air bubble in the AC is completely removed and a collagen shield soaked in Ancef and Decadron is placed on the eye.

16.  The eye is patched over Tobradex ointment and the patch removed the next day.

Currently, DLEK is being investigated by the Endothelial Keratoplasty Group (EKG), which consists of about 25 U.S. sites and 10 international sites. This prospective, multi-site study is being done under strict Institutional Review Board (IRB) approval, and should allow a controlled investigation of the full potential for this procedure as it evolves. This procedure should not be performed at this time without local IRB approval.

References

1.     Terry, MA, Ousley, PJ. Endothelial replacement without surface corneal incisions or sutures: topography of the deep lamellar endothelial keratoplasty procedure. Cornea 2001; 20: 14-18.

2.     Terry, MA, Ousley, PJ. Deep lamellar endothelial keratoplasty in the first United States patients: Early Clinical Results. Cornea 2001; 20: 239-243.

3.     Terry MA, Ousley PJ: Replacing the endothelium without surface corneal incisions or sutures: First U.S. clinical series with the Deep Lamellar Endothelial Keratoplasty Procedure Ophthalmology 2002 (In Press)

4.     Terry, MA: Endothelial Replacement: The Limbal Pocket Approach. Ophthalmology Clinics of North America 2002 (in press)

5.     Terry, MA and Ousley, PJ: Corneal Endothelial Transplantation: Advances in the Surgical Management of Endothelial Dysfunction. Contemporary Ophthalmology 2002 (in press)

6.     Terry, MA: Deep Lamellar Endothelial Keratoplasty (DLEK): Pursuing the Ideal Goals of Endothelial Replacement. EYE 2003 (in press)

7.     Terry, MA, Ousley, PJ: The New Triple Procedure: First World Wide Patients with DLEK combined with Phaco/IOL surgery. American Academy of Ophthalmology Video Library, Annual Meeting, October 2002.

8.     Terry, MA, Ousley, PJ. Endothelial replacement without surface corneal incisions or sutures: Deep lamellar endothelial keratoplasty. American Academy of Ophthalmology: Teaching Videos for purchase. “Best of Show”  AAO 2000.

9.     Terry, MA. The Deep Lamellar Endothelial Keratoplasty Procedure. Video Journal of Ophthalmology: 4^th Quarter Edition, Dec. 2000.

10.  Terry, MA. The evolution of lamellar grafting techniques over 25 years. Cornea 2000; 19: 611-616.

11.  Melles, GR, Eggink, FA, Lander F, et al. A surgical technique for posterior lamellar keratoplasty. Cornea 1998; 17: 618-626.

12.  Melles GRJ, Remeijer L, Geerards AJM, Beekhuis H. The future of lamellar keratoplasty. Current Opinion in Ophthalmology 10:253-259, 1999.

13.  Melles, GR, Lander, F, van Dooren, BR, et al. Preliminary clinical results of posterior lamellar keratoplasty through a sclerocorneal pocket incision. Ophthalmology 2000; 107: 1850-1856.

14.  Melles GR, Lander F, Nieuwendaal C. Sutureless, posterior lamellar keratoplasty: a case report of a modified technique. Cornea 21:325-327, 2002.

15.  Melles GR, Lander F, Rietveld, FJR. Transplantation of descemet’s membrane carrying viable endothelium through a small scleral incision. Cornea 21: 415-418, 2002