DSAEK

1. Descemet’s Stripping Automated Endothelial Keratoplasty (DSAEK)

2. Review of Corneal Anatomy Epithelium Bowman’s layer Stroma Newly Identified Dua's Layer 1 Descemet’s membrane Endothelium

3. Endothelial layer At birth approx 4200 cells/mm 2 Cells have a pump mechanism for removing fluid from the cornea Do not replicate Normal adult count 2800 c/mm 2 Gross corneal edema with if <800 cells/mm 2

4. The Evolution of Corneal Transplantation

5. First documented successful corneal transplant: by Eduard K. Zirm 2 in 1906. The evolution of keratoplasty : Penetrating Keratoplasty Lamellar Keratoplasty : Anterior Lamellar Keratoplasty SALK DALK Posterior Lamellar Keratoplasty / EK DLEK -DSAEK -DMAEK DSEK -DMEK Contemporary femtosecond laser assisted surgery

6. Principles Type of Transplant Stromal change Illustration PK Full replacement PLK/DLEK Remove some and add some stroma DSEK/DSAEK Add some stroma DMEK No change in stroma

7. DSAEK Descemet’s stripping automated endothelial keratoplasty (DSAEK) is the most frequently performed type of endothelial keratoplasty (EK) in the world today. In 2011, EK overtook penetrating keratoplasty (PK) as the most common optical corneal transplant surgery in the United States .

8. The rise of endothelial keratoplasty over time in the United States

9. History of PLK 1956:The first successful human EK by Tillet 4 . 1998: Melles et al 5 used air to hold a posterior lamellar graft in place. 2000: Terry 6 modified PLK with the introduction of an artificial AC and cohesive visco elastic –DLEK 2004: Melles et al 7 introduced his ‘‘descemetorhexis’’ Price and Price’s 8 ensuing modified procedure was called Descemet’s stripping endothelial keratoplasty (DSEK). 2006:Gorovoy 9 introduced the use of a microkeratome & thus bringing about DSAEK.

10. DSAEK Indications EK is indicated when endothelial dysfunction is the underlying cause of visual loss Fuchs dystrophy: the most common indication for in US in 2011: (48%) 1 Pseudophakik & Aphakik Bullous Kearatopathy : (19.2%) Repeat EK grafting Endothelial failure of an existing PK Rarer indications: Iridocorneal Endothelial Syndrome C.H.E.D.

11. Fuchs Endothelial Dystrophy Inherited condition- AD with variable penetrance. Endothelial cells die at a faster rate causing corneal guttata. Poor vision due to edema or glare caused by the guttata.

12. Contraindications Significant anterior corneal scarring High irregular astigmatism .

13. DSAEK Technique The Terry Unfolding Technique

14. 3 step Procedure

15. Creation of a 5-mm scleral tunnel Descemet’s membrane is scored &stripped using a reverse Terry- Sinskey hook under Healon : Descemetorhexis The precut donor epithelium is marked centrally and with the microkeratome surface cut. (epithelial-side down) in artificial chamber. (ALTK system)

16. The tissue is folded in a 40/60 underfolded ‘‘taco”. Charlie II noncoapting insertion forceps are used to insert the graft into the AC BSS injected to partially unfold of the graft f/b slow air injection beneath the endothelium for complete unfolding. The cornea is compressed with the AC full of air to center the graft and milk fluid out of the interface. The air is exchanged with BSS & reinjected & pt. lies supine for 24 hrs.

17. Post op. DSAEK

18. Newer Modifications Precutting : EBAA certified technicians routinely prepared posterior corneal buttons for DSAEK with a microkeratome , so-called ‘‘precut’’ tissue, since 2006. Advantages : reduced operating room time cutting liability (and potential tissue wastage) transfers to the eye bank. Outcomes : Similar with surgeon-cut tissue 10-13

19. Insertion Techniques What is the best way to insert a DSAEK graft??? Terry unfolding technique uses noncoapting forceps 14 a suture ‘‘pull-through’’delivery 14 use of an insertion device The Busin glide The Tan Endoglide The EndoSerter

20. Lens Extraction Cataract surgery should be attempted alone if endothelial compromise and corneal guttata are minimal in the setting of Fuchs dystrophy. In the presence of endothelial dysfunction and cataract, lens extraction indicated in addition to DSAEK. before, concurrently, or after DSAEK. the ‘‘DSAEK triple procedure’’ shown as effective as post-DSAEK cataract surgery 15 ‘ Ultra-thin DSAEK

21. Complications Graft Dislocation: significant separation of the graft from the recipient posterior stroma most commonly in the first postoperative week Rx.: Intracameral air injection and repositioning: ‘‘ Rebubbling ” Primary Graft Failure (PGF): when DSAEK surgery fails in deturgescing the cornea within 6 weeks postoperatively. almost always induced by surgical trauma.

22. DSAEK: Complications Insertion Method Dislocation Primary Graft Failure Goshe et al (n=787) Charlie II forceps 2% -- Anshu et al (n=695) Forceps/ Busin glide 2.9% -- Terry et al (n=200) Charlie II forceps 1.5% 0% Price (n=200) Kelman /Goosey forcep 14% 3.5%

23. Complications Rejection Host immunologic reaction Mean rate is approximately 10% 16,17 Long-term continuance of a low-dose steroid to prevent rejection. people of African descent: at greater risk of graft rejection Elevated Intraocular Pressure (IOP) Infectious keratitis 18 Endophthalmitis. 19

24. Benefits of DSAEK Faster visual recovery: Generally, patients’ vision improves dramatically 4 to 6 weeks as compared with months to years after PK. Preservation of the anterior corneal curvature Markedly less postoperative astigmatism Tectonic strength of the globe is far superior Less chance of suture related problems, infection, vascularization & rejection

25. Feature DSEK/ DSAEK DMEK Procedure Older Newer Level of difficulty Less More Type of procedure Tissue additive Tissue neutral Induced hyperopia Yes No Artificial anterior chamber Required Not required Microkeratome Required (DSAEK) Not required Inserter ( Endoglide , Forceps) Required Not required Expensive equipments Required Not required Corneal thickness Increased Normal Donor/ recipient intra stromal interface Yes No Endothelial cell loss Yes Yes (more) Endthelium has to pump Thicker cornea Thinner cornea

26. Feature DSEK/ DSAEK DMEK Availability of eye bank prepared donor tissue Yes No Possibility of lateral extension of donor corneal stroma Yes No Stromal graft rejection Yes No Endothelial graft rejection Yes Yes Immediate post op. follow up Less More Interface haze Yes Usually no Peripheral anterior synaechia Greater Lower Centering of donor disc Easy Difficult Tendency of donor disc detachment Less More Rate of visual recovery Slower Faster Percentage of eyes with 20/20 or better vision Lower Higher

27. Challenges Technically challenging & costly for patient Steeper learning curve for surgeon New instrumentation Relatively newer technique: require more long term studies.

28. Future Directives Rho-associated Kinase (ROCK) Inhibitors: Specific ROCK inhibitor has been shown to increase proliferation and improve wound healing in cultivated primate endothelial cells in vitro. 20,21 Topical ROCK inhibitors may play a role in the endothelial dysfunction in years to come. DMEK Considered as the perfect anatomic replacement for eyes with endothelial failure. Better, faster visual recovery with less ECL Popularity may grow with newer techniques. Endothelial Exchange: Theoretically the best option Practically ???

29. Conclusion DSAEK is an effective PLK procedure to treat endothelial decompensation . Visual outcome comparable to PKP. ALTK system gives reproducible results in making Donor button. DSAEK will continue to be the treatment of choice for more complex anterior segment cases like aphakia , in the setting of AC IOL, and in eyes with filtering tubes or blebs.

30. References Human Corneal Anatomy Redefined: A Novel Pre- Descemet's Layer ( Dua's Layer) . Ophthalmology. 2013.120;5:881-885. Mannis  MJ,  Mannis  AA:  Corneal transplantation: a history in profiles .  Belgium, JP Wayenborgh , 1999. Eye Bank Association of America.EBAA 2005-2011 Eye Banking Statistical Reports. Washington, DC: Eye Bank Association of America; 2005-2011. Tillet CW. Posterior lamellar keratoplasty.Am J Ophthalmol . 1956;41:530–533. Melles GR, Eggink FA, Lander F, et al. A surgical technique for posterior lamellar keratoplasty . Cornea. 1998;17:618–626. Terry MA, Ousley PJ. Deep lamellar endothelial keratoplasty in the first United States patients: early clinical results. Cornea. 2001;20:239–243. Melles GR, Wijdh RH, Nieuwendaal CP. A technique to excise the Descemet membrane from a recipient cornea ( descemetorhexis ). Cornea. 2004;23:286–288. Price FW Jr , Price MO. Descemet’s stripping with endothelial keratoplasty in 50 eyes: a refractive neutral corneal transplant. J Refract Surg. 2005;21:339–345. Gorovoy MS. Descemet -stripping automated endothelial keratoplasty . Cornea. 2006;25:886–889. Terry MA. Endothelial keratoplasty : a comparison of complication rates and endothelial survival between precut tissue and surgeon-cut tissue by a single DSAEK surgeon. Trans Am Ophthalmol Soc. 2009;107:184–191. Chen ES, Terry MA, Shamie N, et al. Precut tissue in Descemet’s stripping automated endothelial keratoplasty donor characteristics and early postoperative complications. Ophthalmology. 2008;115:497–502. Terry MA, Shamie N, Chen ES, et al. Precut tissue for Descemet’s stripping automated endothelial keratoplasty : vision, astigmatism, and endothelial survival. Ophthalmology. 2009;116:248–256.

31. References Price MO, Baig KM, Brubaker JW, et al. Randomized, prospective comparison of precut vs surgeon-dissected grafts for Descemet stripping automated endothelial keratoplasty . Am J Ophthalmol . 2008;146:36–41. Kaiserman I, Bahar I, McAllum P, et al. Suture-assisted versus forceps-assisted insertion of the donor lenticula during Descemet stripping automated endothelialkeratoplasty . Am J Ophthalmol . 2008;145:986–990. Terry MA, Shamie N, Chen ES, et al. Endothelial keratoplasty for Fuchs’ dystrophy with cataract: complications and clinical results with the new triple procedure. Ophthalmology. 2009;116:631–639. Mearza AA, Qureshi MA, Rostron CK. Experience and 12-month results of Descemet stripping endothelial keratoplasty (DSEK) with a small-incision technique. Cornea. 2007;26:279–283. Lee WB, Jacobs DS, Musch DC, et al. Descemet’s stripping endothelial keratoplasty : safety and outcomes: a report by the American Academy of Ophthalmology. Ophthalmology. 2009;116:1818–1830. Review. Sharma N, Agarwal PC, Kumar CS, et al. Microbial keratitis after Descemet stripping automated endothelial keratoplasty . Eye Contact Lens. 2011;37:320–322. Chew AC, Mehta JS, Li L, et al. Fungal endophthalmitis after Descemet stripping automated endothelial keratoplasty —a case report. Cornea. 2010;29:346–349. Okumura N, Koizumi N, Ueno M, et al. Enhancement of corneal endothelium wound healing by Rho-associated kinase (ROCK) inhibitor eyedrops . Br J Ophthalmol . 2011;95:1006–1009. Okumura N, Ueno M, Koizumi N, et al. Enhancement on primate corneal endothelial cell survival in vitro by a ROCK inhibitor. Invest Ophthalmol Vis Sci. 2009;50:3680–3687.

32. Descemet Stripping Automated Lamellar Keratoplasty “DSAEK” Alaa El Danasoury , MD Medical Director Chief Refractive Surgery Service Magrabi Hospital & Centers Thank You