Descemet Stripping Automated Endothelial Keratoplasty with a Graft Insertion Device : Technique and Early Results Dr Wei-Boon KHOR, MRCS(Ed), Dr Jodhbir.

Descemet Stripping Automated Endothelial Keratoplasty with a Graft Insertion Device : Technique and Early Results Dr Wei-Boon KHOR, MRCS(Ed), Dr Jodhbir S MEHTA, FRCS(Ed), Prof Donald TH TAN, FRCS(G)

Singapore National Eye Centre (SNEC)and Singapore Eye Research Institute (SERI)

WB Khor has no financial interests.Jodbir Mehta and Donald Tan have financial interests in the EndoGlide (Network Medical Products)Singapore Eye Research Institute

IntroductionDescemet Stripping Automated Endothelial Keratoplasty (DSAEK) is a form of selective corneal lamellar transplant surgery with many advantages over penetrating keratoplasty (PK)However, there is concern over the degree of endothelial cell loss in DSAEK a recent review reported an average loss of 37% (range 25%-54%) at 6 months, and 42% (range 24%-61%) at 12 months1Graft insertion through a small incision with the current taco-fold technique may be a major cause of endothelial cell damageNew inserters are now emerging which are designed to minimize surgical trauma and reduce loss in endothelial cell density (ECD)1. Lee, W.B., et al., Descemet's stripping endothelial keratoplasty: safety and outcomes: a report by the American Academy of Ophthalmology. Ophthalmology, 2009. 116(9): p. 1818-30.

PurposeThis poster describes the use of the EndoGlide (Network Medical Products, North Yorkshire, UK), a new graft insertion device for use during DSAEK

We also report the early clinical results of the Singapore National Eye Centre (SNEC) EndoGlide Trial

The SNEC EndoGlide Trial is an IRB-approved prospective clinical trial aimed at evaluating the use of the EndoGlide in 100 eyes

The EndoGlideThe EndoGlide consists of three components the Glide Capsule, the Glide Introducer, and the Preparation Base Glide CapsuleGlide IntroducerPreparation BaseGlide IntroducerGlide CapsuleDiagram on the left is courtesy of Network Medical Products.

A central ridge within the Glide Capsule (Figure A) enables automatic coiling of the donor tissue into a double-coil configuration when pulled into the chamber

Double-coiled graft outlined from the front (Figure B) and the top (Figure C); the endothelial surface is on the inside of the double-coil

The Capsule can hold a double-coiled graft without endothelium to endothelium touchaccomodates a graft of up to 10 mm in diameter and 250 um in thicknessABCCentral Ridge

Surgical TechniqueMicrokeratome lamellar dissection of the donor cornea is performed and then trephined to the desired diameter

Figure D: Leading edge of the posterior lenticule can be inked on the stromal edge for easy visualization

Figure E: The internal lumen of the Glide Capsule is lubricated with balanced salt solution (BSS)

Figure F: Both anterior cap and posterior donor lenticule are gently separated with BSS and then transferred (endothelial side up) onto the Preparation Base

DEF

Figure G: Straight forceps are introduced through the anterior opening of the Capsule to grasp the leading edge of the graft

Figure H: As the graft is drawn into the Capsule, it rolls into the double-coil configuration when the lateral edges of the donor encounter the central internal ridge

Figure I: The graft is drawn completely into the Capsule

GHIForceps introduced here

Figure J: The purple Glide Introducer is inserted into the posterior opening of the Capsule and locked into place

The assembled EndoGlide is removed from the Preparation Base and inverted for insertion

Figure K: The anterior glide surface of the EndoGlide is inserted into the eye through a 4.5mm scleral tunnel and advanced fully in the AC Figure L: Through a nasal paracentesis, forceps are passed over the glide surface and used to grasp the stromal edge of the graft JKL

Figure M : The graft is simply pulled out of the EndoGlide and into the AC

Figure N : Within the AC, the graft will uncoil, endothelial surface down. Moderate BSS flow from a pre-placed AC maintainer will facilitate unfolding. Gentle movements of the graft with the forceps will also aid in the full uncoiling process

Figure O: Whilst still holding the graft with forceps, the EndoGlide is removed and a small air bubble is injected beneath the graft to float it against the recipient stromal surface

The surgery is then completed in the usual mannerMNO

ResultsThe EndoGlide has been used in 26 eyes of 26 patients so far (performed by 2 surgeons DTHT and JSM)

Diagnosis :- 11 Pseudophakic/Aphakic Bullous Keratopathy- 9 Fuchs Endothelial Dystrophy- Others : Post-Laser PI Bullous Keratopathy, Descemet Detachment, PPMD, Failed DSAEK

Procedures performed: - 12 DSAEK- 11 Phaco-DSAEK- 3 DSAEK + IOL exchange

Median donor diameter: 8.75 mm (range 8.25-9.5)Mean donor thickness: 187 microns (SD+32)

We found that coiling of the graft and graft insertion were easily achieved in all cases For donor coiling, the use of a BSS cannula or Sinskey hook to gently stroke up the stromal edges of the graft was useful to achieve a perfect double-coil configuration

Immediate post-op resultsNo primary iatrogenic graft failuresNo donor dislocations

13 patients have completed 6 months follow-up (and 4 have completed 1 year follow-up)Best corrected VA : range from 6/7.5 to 6/45No patient has lost any lines of visionMean ECD : 2528 (SD + 337) at 6 monthsMean ECD loss : 17.6% at 6 months

DiscussionThe EndoGlide enables graft insertion through a 4.5mm incision with ease, minimal graft manipulation, and with full control of the graft at all times during DSAEK

Early results show that it is safe in clinical use; no immediate endothelial complications such as primary graft failure or graft dislocation so far

Initial 6 months ECD results are promising, but more patients and longer follow-up times are required to determine the long-term ECD loss with EndoGlide useComments? Email