Corneal Endothelial Transplantation:

Descemet's Stripping Endothelial Keratoplasty (DSEK)

Sudeep Pramanik, MD, MBA, Kenneth M. Goins, MD, John E. Sutphin, MD

February 23, 2006, updated April 9, 2007

For the past 50 years, penetrating keratoplasty (PKP) has been the standard of care for patients with corneal endothelial failure. PKP can result in optically clear corneas, but the refractive results are poor. Visual recovery in patients can take between 6-24 months and many series report 50% of patients require contact lenses to achieve useful vision (Muraine et al, 2003, Ing et al, 1998, Tuft & Gregory 1995, Price et al, 1991). Patients with bilateral disease must, therefore, wait a long time for treatment in their second eye until problems in their first eye resolve. In the developing world, these problems are compounded as there is a high rate suture related complications and corneal transplant failure (Dandona et al, 1997). Late rupture of wounds is also a serious risk (Elder & Stack, 2004).

Modern History of Endothelial Transplant

In 1998, Dutch ophthalmologist Gerrit Melles, MD described a technique in which the inside layers of the cornea were manually dissected and selectively replaced (Melles et al, 1998). In 2001, Mark Terry, MD described a modified technique in which the dissection was performed with viscoelastic and termed his technique deep lamellar endothelial keratoplasty, or DLEK (Terry & Ousley 2001). The manual dissection is tedious and involves a steep learning curve. Dr. Melles has since developed a technique that involves stripping of Descemet’s membrane instead of a lamellar dissection, which has been termed Descemet’s stripping endothelial keratoplasty, or DSEK (Melles et al, 2004).

Advantages of Endothelial Transplant

Endothelial transplantation offers several advantages including less postoperative astigmatism, faster visual recovery, and stronger wound integrity (Terry & Ousley 2001). Theoretically, there is less risk of rejection since less of the patient’s tissue is replaced. Finally, there is the potential to make more efficient use of transplant tissue—using the endothelium for DLEK or DSEK in one patient and the stroma for a lamellar graft in another. It is useful in patients with varying types of endothelial dysfunction, including Fuchs dystrophy, Pseudophakic bullous keratopathy (PBK), Aphakic bullous keratopathy (ABK), and Posterior Polymorphous dystrophy (PPMD) (Melles et al, 1998, Terry & Ousley 2001).

Strengths and Weaknesses of DLEK

The steps of DLEK are described in Table 1. Because DLEK involves dissection of a ledge of tissue on the inner aspect of the cornea, it provides mechanical support that results in less chance of postoperative lenticle dislocation. This allows successful surgery to be performed in apkakia and after glaucoma filtration surgery. In our experience, more advanced cases of endothelial failure with significant corneal edema and pachymetry over 700 microns, the lamellar dissection is much easier than early in the course of endothelial dysfunction.

The disadvantages of DLEK are the technical challenge of the procedure, the risk of perforation, and the need for special designed blades for dissection. Another source of frustration for surgeons is the haze that may form in the interface between the host and donor corneas. Fortunately, we have found that this haze does not correlate with reduced visual acuity and lessens over time (Pramanik et al, 2005).

We use DLEK in patients who cannot lie flat (i.e.-back problems), patients without a true anterior chamber (i.e.-aphakia), and those who have undergone previous glaucoma filtration surgery.

Table 1: Surgical steps of deep lamellar endothelial keratoplasty (DLEK)
  • Conjunctival peritomy with Wescott scissors and 0.12 forceps
  • Diamond knife for 5mm scleral tunnel 1.5 mm back from limbus (350 micron depth)
  • Paracentesis on each side of scleral tunnel
  • Fill anterior chamber with viscoelastic (Healon/Healon 5)
  • Dissect away posterior cornea stroma
  • Mark area for removal
  • Enter anterior chamber with keratome
  • Remove posterior cornea with scissors
  • Remove viscoelastic with irrigation/aspiration handpiece
  • Temporary suture in scleral tunnel
  • Prepare donor lenticle (manual or automated)
  • Fold donor lenticle and grasp with forceps or place on shovel
  • Remove temporary suture and place donor lenticle into the AC
  • Suture scleral tunnel closed
  • Unfold lenticle using air in AC
  • Tuck into place using special hooks
  • Refill AC with BSS
  • Close conjunctiva, add injections of Ancef and Decadron if desired

A video of this procedure can be found at:
http://www.EyeRounds.org/cases/case33-DLEK-deeplamellarendothelialkeratoplasty.htm

Strengths and Weaknesses of DSEK

The steps of DSEK are described in Table 2. DSEK has grown more rapidly in popularity because it is technically easier and faster than DLEK (Price & Price 2005). Our typical operative time for this transplant is 30-60 minutes. It results in a more optically pure interface and has excellent visual recovery.

The disadvantages are that the patient must lie flat for the air bubble to hold the transplant disc in place while the endothelium begins to pump. There is a risk of pupillary block glaucoma, which can be overcome by releasing half of the air from the anterior chamber one hour postoperatively and by dilating the pupil with 1% atropine at the end of the case. Early reports indicated early postoperative dislocation of the transplant disc in 10-15% of the cases (Price & Price, in press, Gorovoy & Price 2005). Modifications of the technique including the scraping of peripheral stroma and removal of fluid from the interface with external massage or stab incisions with a 15-degree blade have resulted in a dislocation rate around 1% (Gorovoy & Price 2005).

Table 2: Surgical steps of Descemet's stripping endothelial keratoplasty (DSEK)
  • Conjunctival peritomy
  • 5mm wide scleral tunnel 1.5 mm back from limbus
  • Paracentesis on each side of scleral tunnel
  • Maintain anterior chamber with Healon or infusion
  • "Score" Descemet’s membrane with Sinskey hook
  • "Strip" off Descemet’s with hook, strippers or irrigation/aspiration handpiece
  • "Roughen" edge around area of dissection
  • Temporarily close scleral tunnel
  • Prepare donor lenticle
  • Fold donor tissue and place in AC
  • Suture scleral tunnel closed
  • Unfold lenticle and position with air in AC
  • "Massage" fluid out from interface
  • Dilate pupil (1% atropine)
  • Close conjunctiva and administer subconjunctival injections of Ancef and Decadron
  • Leave patient supine in postoperative recovery area 1 hours
  • Examine at slit lamp—if lenticle is in good position, push on paracentesis to release 50-60% of air bubble
  • Patient should remain supine (face up) for next day

Click here to view video. File is very large, please wait for it to load. (approx 7MB)

We use DSEK in patients with early endothelial failure where the view into the anterior chamber allows adequate visualization of our instruments. It is best in cases where the anatomy of the anterior chamber is good (i.e.-phakia, uncomplicated pseudophakia, and no previous filtration surgery). It is also useful in PKP patients with endothelial failure who had minimal astigmatism before they experienced graft failure.

Future Goals for Endothelial Transplant

Future endothelial transplant research will focus on making the procedure more reliable and less surgeon-dependent. Studies are underway to assess the ability of the eye banks to provide pre-cut tissue to reduce intraoperative time and make more effective use of donated corneas. Advances in techniques to minimize trauma to endothelial cells will improve the longevity of these surgeries. Finally, plans are underway to compare endothelial transplantation to penetrating keratoplasty in a prospective trial.

References

  1. Muraine M, Sanchez C, Watt L, et al. Long-term results of penetrating keratoplasty. A 10-year-plus retrospective study. Graefes Arch Clin Exp Ophthalmol 2003; 241:571-6.
  2. Ing JJ, Ing HH, Nelson LR, et al. Ten-year postoperative results of penetrating keratoplasty. Ophthalmology 1998; 105:1855-65.
  3. Tuft SJ, Gregory W. Long-term refraction and keratometry after penetrating keratoplasty for keratoconus. Cornea 1995; 14:614-7.
  4. Price FW, WE Whitson, RG Marks. Graft survival in four common groups of patients undergoing penetrating keratoplasty. Ophthalmology 1991; 98:322-8.
  5. Dandona L, Naduvilath TJ, Janarthanan M, Ragu K, Rao GN. Survival analysis and visual outcome in a large series of corneal transplants in India. Br J Ophthalmol. 1997; 81(9):726-31.
  6. Elder MJ, Stack RR. Globe rupture following penetrating keratoplasty: how often, why, and what can we do to prevent it? Cornea. 2004; 23(8):776-80.
  7. Melles GR, Eggink FA, Lander F, et al. A surgical technique for posterior lamellar keratoplasty. Cornea. 1998; 17:618-626.
  8. Terry MA, Ousley, PJ. Deep lamellar endothelial keratoplasty in the first United States patients: early clinical results. Cornea. 2001; 20:239-243.
  9. Melles GR, Wijdh RH, Niewendaal CP. A technique to excise the Descemet membrane from a recipient cornea (descemetorhexis). Cornea. 2004; 23:286-8.
  10. Pramanik S, Sjoberg SA, Goins KM, Sutphin JE. Correlation between interface opacity and visual acuity in DLEK. Abstract. Presented at 2005 EBAA Meeting at the American Academy of Ophthalmology, Chicago, IL. In press.
  11. Price FW, Price MO. Descemet’s stripping with endothelial keratoplasty (DSEK) in 50 eyes: a refractive neutral cornea transplant. J Refract Surg. 2005; 21:339-345.
  12. Price FW, Price MO. DSEK in 200 eyes: early challenges and techniques to promote donor adherence. J Cataract Refract Surg. In press.
  13. Gorovoy MS, Price FW. New technique transforms corneal transplantation. Cataract Refract Surg Today. 2005; (Nov/Dec.):1-4.

Suggested citation format: Pramanik S, Goins, KM, Sutphin JE: Corneal Endothelial Transplantation: Descemet's Stripping Endothelial Keratoplasty (DSEK). Eyerounds.org. February 23, 2006; Available from: http://www.EyeRounds.org/cases/54-Descemets-Stripping-Endothelial-Keratoplasty-DSEK.htm