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 National Eye Centre Singapore Eye Research Institute

Introduction Descemet 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 months1 Graft insertion through a small incision with the current “taco-fold” technique may be a major cause of endothelial cell damage New 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.

Purpose This 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 EndoGlide Glide Capsule Glide Introducer Glide Capsule Preparation Base Glide Introducer The EndoGlide consists of three components – the Glide Capsule, the Glide Introducer, and the Preparation Base Diagram on the left is courtesy of Network Medical Products.

Central Ridge 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 touch accomodates a graft of up to 10 mm in diameter and 250 um in thickness A B C

Surgical Technique Microkeratome 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 D E F

Figure I: The graft is drawn completely into the Capsule Forceps introduced here 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 G H I

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 J K L

The surgery is then completed in the usual manner 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 manner M N O

Results The 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 results No primary iatrogenic graft failures No 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 6/45 No patient has lost any lines of vision Mean ECD : 2528 (SD + 337) at 6 months Mean ECD loss : 17.6% at 6 months

Discussion The 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 use Comments? Email <khor.wei.boon@singhealth.com.sg>