Ординатура / Офтальмология / Английские материалы / Corneal Endothelial Transplant (DSAEK, DMEK & DLEK)_John_2010

Difficulty encountered: RSH is difficult to use, as it was not designed to work on the ceiling of the recipient cornea.

Main benefit: John DSAEK Fixation Hook (ASICO Inc., Westmont,IL,AE-2182)(PatentPending)(Figures11-14to11- 17)hasaretractablecentralcablewhichallowsforretracting the hook after use. It can also be used on the outer corneal surface to explore the slits “venting incisions”used to enhance donor disk attachment, and drain fluid from the donor-hostinterface.

John DSAEK Glider

Identification of surgical step: Removal of wrinkles of folds in the donor corneal disk after attachment of the donor corneal disk to the inner surface of the recipient cornea.

Difficulty encountered: Lindstrom Roller is designed for use with LASIK surgery. It has been used for DSAEK, however, it lacks curvature along the horizontal axis which creates the need for multiple rolls.

Main benefit: John DSAEK Glider (ASICO Inc., Westmont, IL, AE-2879) (Patent Pending) (Figures 11-18 and 11-19) is specifically designed for use in DSAEK surgery. Its unique

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B

Figures 11-14A and B: (A) John DSAEK Fixation Hook (ASICO, Westmont, IL; AE-2182) (Patent Pending); (B) Close-up view of the tip of John DSAEK Fixation Hook (ASICO, Westmont, IL; AE-2182) (Patent Pending) showing the retractable central cable which allows for retracting the hook after use within the recipient anterior chamber.

Figure 11-16: Magnified view of the use of the John DSAEK Fixation Hook (ASICO, Westmont, IL; AE-2182) (Patent Pending) to fixate the donor disk against the inner surface of the recipient cornea and unfolding the fixated donor disk with an air-bubble.

Figure 11-17: After unfolding of the donor corneal disk, the John DSAEK Fixation Hook’s inner cable is retracted and withdrawn from the anterior chamber (ASICO, Westmont, IL; AE-2182) (Patent Pending); Insert Photo – Shows the fully unfolded donor corneal disk that is attached to the inner surface of the host cornea.

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Figures 11-18A and B: (A) John DSAEK Glider (ASICO, Westmont, IL; AE-2879) (Patent Pending); (B) Higher magnification of the John DSAEK Glider.

design and curvatures allows for corneal contour-oriented contact between the outer corneal dome and the inner surface of the Glider. All regions of the outer corneal surface can be gently and smoothly “ironed” to diminish and/or eliminate donor disk wrinkles at the donor-host interface.

John DSAEK Marker (8 mm/9 mm)

Identification of surgical step: Marking the corneal surface of the recipient cornea with a fixed diameter of either 8 mm or 9 mm diameter.

Difficulty encountered: Using the disposable trephine to mark the recipient corneal surface can be difficult especially in a deep set eye and can result in an eccentric mark.

Main benefit: John DSAEK Marker (ASICO Inc., Westmont, IL, AE-2712) (Figure 11-20) facilitates easy marking of the patient’s corneal surface with or without epithelium, using either end of the single instrument for a fixed diameter of

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Figures 11-21A and B: (A) Busin Glide (Moria Inc., Antony Cedex, France) (Photo: Courtesy, Moria Inc.); (B) Intraoperative photograph of Busin Glide (Moria Inc., Antony Cedex, France), used to introduce the donor corneal disk into the recipient anterior chamber (Photo: Courtesy, Moria, Inc.).

8 mm or 9 mm. This instrument helps in good centration and eliminates eccentric marks on the cornea. The Descemetorhexis is carried out within this circular mark

(Figure 11-20).

Other DSAEK Instruments

The other instruments for DSAEK made by Moria, Inc. (Antony Cedex, France), DORC, Inc. (The Netherlands), Katena Products Inc. (Denville, NJ); and Rhein Medical Inc. (Tampa, FL) are listed in Table 11-1 and Figure 11-21.

Conclusion

In conclusion, this chapter has provided an in-depth listing and review of the types of surgical instruments for DSAEK surgery that are currently available commercially. In addition, intraoperative photographs display the use of some of these instruments. The surgeon has to choose his surgical instruments to facilitate the optimal DSAEK

surgery thus providing a consistently good surgical outcome and best possible visual outcome for his patients.

References

1. John T. DXEK surgery, corneal disk detachment (Consultation Section). Ann Ophthalmol 2006;38:169-84.

2. John T. Selective tissue corneal transplantation: a great step forward in global visual restoration (Editorial) 2006;1:5-7.

3. John T (Ed.): Surgical Techniques in Anterior and Posterior Lamellar Corneal Surgery. Jaypee Brothers Medical Publishers

(P) Ltd., New Delhi, India, 1-687.

4. John T (Ed.): Step by Step Anterior and Posterior Lamellar Keratoplasty, Jaypee Brothers Medical Publishers (P) Ltd., New Delhi, India, 1-297.

5. Melles GR, Eggink FA, Lander F, Pels E, Rietveld FJ, Beekhuis WH, Binder PS. A surgical technique for posterior lamellar keratoplasty. Cornea 1998;17:618-26.

6. 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.

7. Terry MA, Ousley PJ. Deep lamellar endothelial keratoplasty in the first United States patients: early clinical results. Cornea 2001;20:239-43.

8. Terry MA, Ousley PJ. Replacing the endothelium without corneal surface incisions or sutures: the first United States clinical series using the deep lamellar endothelial keratoplasty procedure. Ophthalmology 2003;110:755-64.

9. Terry MA, Ousley PJ. Rapid visual rehabilitation after endothelial transplants with deep lamellar endothelial keratoplasty (DLEK). Cornea 2004;23:143-53.

10. Terry MA, Ousley PJ. Corneal endothelial transplantation:

advances in the surgical management of endothelial dysfunction. Contemporary Ophthalmology 2002;1(26):1-8.

11. Terry MA, Ousley PJ. Small-incision deep lamellar endothelial keratoplasty (DLEK): six-month results in the first prospective clinical study. Cornea 2005;24:59-65.

12.Ousley PJ, Terry MA. Stability of vision, topography, and endothelial cell density from 1 year to 2 years after deep lamellar endothelial keratoplasty surgery. Ophthalmology 2005;

112:50-57.

13. John T. Stitchless corneal transplantation. Cataract and Refractive Surgery Today 2004;4(8):27-30.

14.Melles GRJ, Wijdh RHJ, Nieuwendaal CP. A technique to excise the Descemet membrane from a recipient cornea (Descemetorhexis). Cornea 2004;23:286-8.

15.Melles GRJ, Lander F, Rietveld FJR. Transplantation of Descemet’s membrane carrying viable endothelium through a small scleral incision. Cornea 2002;21:415-8.

16.John T. Use of indocyanine green in deep lamellar endothelial keratoplasty. J Cataract Refract Surg 2003;29:437-43.

17.Melles GR. Posterior lamellar keratoplasty: DLEK to DSEK to DMEK. Cornea. 2006;25:879-81.

18.Price FW Jr, Price MO. Descemet’s stripping with endothelial keratoplasty in 200 eyes: Early challenges and techniques to enhance donor adherence. J Cataract Refract Surg. 2006;32: 411-8.

19.Price MO, Price FW. Descemet’s stripping endothelial keratoplasty. Curr Opin Ophthalmol 2007;18:290-4.

20.Price MO, Price FW. Descemet stripping with endothelial keratoplasty for treatment of iridocorneal endothelial syndrome. Cornea 2007;26:493-7.

21.Mearza AA, Qureshi MA, Rostron CK. Experience and 12-month results of descemet-stripping endothelial keratoplasty (DSEK) with a small-incision technique. Cornea 2007;26:279-83.

Introduction

The creation of an artificial anterior chamber (ACC)1 is a major milestone in the field of corneal surgery. This introduction of the ACC is changing the surgical landscape of corneal transplantation to a more favorable, and evolving field of lamellar corneal surgery. The pre-ACC era dealt with utilizing whole globes or corneoscleral button that was wrapped tightly around a glass orbital implant for the lamellar graft dissection.2 Issues during this era included difficulties in obtaining whole globes, stabilization of the whole globe for lamellar dissection, and less than optimal instrumentation.

Artificial anterior chamber was first described by Ward and Nesburn in 1976.1 They described a way to trephine the donor cornea from the anterior surface when the donor corneal-scleral tissue was mounted on an instrument that formed a seal around the scleral rim of the excised donor cornea, allowing the endothelium to be supported physically by the liquid storage medium.1 Hence, the artificial anterior chamber protected the donor endothelial cells from damage as if they were still in the intact globe.1 Although it was thought to provide better donor-recipient match for full-thickness penetrating keratoplasty (PKP), since both the donor and the recipient corneas were trephined from the anterior corneal surface with the same diameter trephine, the use of such an ACC extended across boundaries from PKP to lamellar keratoplasty (LKP). Since the initial description, various modifications and improvements in the ACC has been made giving ophthalmic surgeons the ability to trephine to any desired donor corneal depth.2-16 Artificial anterior chambers may be utilized for both manual lamellar dissection, or automated lamellar dissection of the donor cornea using a microkeratome and the Moria ALTK system (Moria SA, Antony, France).

This chapter provides an introduction to the various AAC that are currently available in the United States at the time of this writing.

Surgical Objective

Surgical objective is to obtain a lamellar corneal disk of the desired thickness, diameter, an even surface with an uniplanar cut to augment the donor-host corneal interface, ease of operation, and avoidance of disk perforation.

Types of AAC

1.Reusable ACC

2.Disposable ACC

Reusable ACC

Reusable ACC as the name suggests can be used repeatedly provided care is taken not to damage the ACC unit by improper handling.

Types

a.Moria ACC (manual), and Moria ALTK system (automated with microkeratome)

b Bausch and Lomb ACC (manual).

Moria ACC

Moria ACC utilizes the Evolution3 console (Moria, Inc.) that is fully compatible with all Moria microkeratomes including the LSK, M2, and the CB units. Currently the CB microkeratome is the unit that is provided for the Moria ALTK system. The Evolution3 console has built-in safety features and provides ease of use for the surgeon and operating room staff. It runs on wall current and has a battery back-up for uninterrupted use. It has two high pumps that provide a quick and stable vacuum for the procedure. The Moria unit for lamellar surgical procedures is called the ALTK system.

The Moria ALTK system can be used for anterior lamellar keratoplasty (ALK) (extra-ocular procedure) or for deep lamellar endothelial keratoplasty (DLEK) [See also Section 8, Deep Lamellar Endothelial Keratoplasty (DLEK)] or for Descemet Stripping Automated Endothelial Keratoplasty (DSAEK) [See also Section 9, Descemet Stripping Automated Endothelial Keratoplasty (DSAEK)]. The indications for these procedures are listed in the respective chapters.

The donor corneoscleral tissue can be used for ALK using preferably, the automated technique for the best interface (with microkeratome use) or alternatively if the ALTK system is not available in the operating room, then, the Moria ACC can be used for manual dissection of the donor lamellar disc. When using the ACC with manual dissection, the partial thickness anterior lamellar dissection of the donor cornea can be performed after partial trephination to the desired depth using the Moria ACC and the Hanna trephine (Moria, Inc.) that is set to the required depth in microns. The Hanna trephine (Moria, Inc.) seats well on the Moria ACC and allows for stable partial thickness trephination of the donor cornea from the epithelial side. This is followed by manual lamellar dissection of the donor corneal tissue. The same trephine with the same blade can be used on the recipient cornea for the same diameter disk resection as that of the donor lamellar disk. Unlike the Moria ALTK system, with the