UPDATE ON CORNEAL TRANSPLANTATION. Frank S. Hwang M.D. Assistant Professor Cornea, External Disease and Refractive Surgery

Transcription

1 UPDATE ON CORNEAL TRANSPLANTATION Frank S. Hwang M.D. Assistant Professor Cornea, External Disease and Refractive Surgery

2 OBJECTIVES Types of corneal transplantation Donor Selection of corneal tissue Penetrating keratoplasty Anterior Lamellar Keratoplasty Endothelial Keratoplasty

3 CORNEAL TRANSPLANTATION Cornea: immunologic privilege, first successfully transplanted solid tissue (1905) In the USA, ~ 40,000 corneal transplantations vs. ~ 12,000 other solid-organ transplantations.

4 Penetrating keratoplasty (PK or PKP): full-thickness, gold standard Lamellar keratoplasty: partial-thickness Anterior lamellar keratoplasty (ALK): Superficial ALK (SALK) Hemi-automated lamellar keratoplasty (HALK) Deep ALK (DALK) Posterior lamellar keratoplasty or endothelial keratoplasty (EK) Descemet stripping and endothelial keratoplasty (DSEK) Descemet s membrane endothelial keratoplasty (DMEK) 53% 5% 35%

5 DONOR CORNEA CONSIDERATION Donor corneas: stored in Optisol-GS Exclusion criteria: unknown cause of death, systemic infections, CNS infection, leukemia, ocular hx (infection/inflammation, malignancy, prior refractive sx), Hep B/C, HIV, etc Certain considerations: endothelial cell density (ECD) >2000/mm 2, death-to-preservation time, donor age, tissue storage time

6 PENETRATING KERATOPLASTY Indications: any stromal or endothelial corneal pathology i.e. keratoconus, failed graft, post-cataract edema, corneal dystrophies/degenerations trephination of donor tissue, mm larger trephination & excision of host cornea suture (interrupted, continuous, or combined)

7 PK COMPLICATIONS Intraoperative: lens/iris damage, poor graft/donor centration, iris/vitreous incarceration, damage to donor endothelium, hemorrhage Postoperative: wound leak, flat chamber, glaucoma, endophthalmitis, persistent epi defect, recurrent primary disease, epithelial ingrowth, primary graft failure, infected sutures, graft rejection, regular/irregular astigmatism (most common)

8 THE CORNEA DONOR STUDY (CDS) Designed as a prospective, double-masked, controlled trial to determine: The role of donor age in long-term corneal graft survival The effect of ABO blood type matching on corneal graft survival The effect of donor age on long-term donor endothelial cell density Patient enrollment : 40 to 80 years old, and in moderaterisk corneal transplant categories, mostly endothelial diseases, Fuchs dystrophy 675 (61%), Pseudophakic/aphakic corneal edema 369 (34%)

9 THE CDS RESULTS FIVE YEAR Graft failure, defined as a re-graft or a cloudy cornea that was sufficiently opaque as to compromise vision for a minimum of 3 consecutive months. CDS 5-year result Donor age (yr) Graft survival 86% 86% Median cell loss Median ECD 824 cells/mm2 69% 75% * 654 cells/mm2 * ABO incompatibility does NOT increase the risk of transplant failure

10 THE CDS RESULTS TEN YEAR CDS 10- year result Donor age (yr) Graft survival 77% 71% Median cell loss Median ECD 628 cells/mm2 76% 79% * 550 cells/mm2 * When analyzed as a continuous variable, higher donor age was associated with lower graft success beyond first 5 years (P<0.001) The 10-year success rate was relatively constant for donors aged 34 to 71 years (75%). The success rate was higher for 80 donors aged 12 to 33 years (96%) and lower for 130 donors aged 72 to 75 years (62%)

11 Anterior Lamellar Keratoplasty (ALK) Indicated in corneal conditions where the endothelium is still functional, such as ectatic disorders, superficial scars, and various dystrophies. Superficial ALK (SALK): pathology limited to anterior third Hemi-automated lamellar keratoplasty (HALK): 50% thickness Deep ALK (DALK): deeper stroma Dissections were achieved freehand or automated by a microkeratome or femtosecond laser Stroma-to-stroma interfaces, as in SALK, can degrade visual acuity over time Stroma-to-DM interfaces, as in DALK, provide higher quality vision HALK: donor cornea prepared with microkeratome, recipient cornea prepared freehand

12 ANTERIOR LAMELLAR KERATOPLASTY (ALK) Advantanges: Extraocular procedure resulting in a low risk of many complications, including transplant rejection and failure. Less topical steroid use than PK or EK. Early suture removal safe. Disadvantages: Usually more technically demanding than PK. Fails unless host endothelium is healthy. Regular and irregular astigmatism the same as for PK. Most common intraocular complication is Descemet s performation and conversion to PK.

13 12-mo DALK (28) PK (28) BCVA logmar 0.39 (20/50) 0.31 (20/40) Endothelial loss 12.9% 27.7% * Spherical equivalent Endothelial rejection 0 3 (Micro)perforation of the Descemet s membrane occurred in 32% of the DALK eyes, and 18% of the patients required conversion to PK

14 Endothelial Keratoplasty (EK) Indicated in endothelial dysfunctions such as pseudophakic/phakic bullous keratopathy, Fuch s dystrophy, Posterior Polymorphous dystrophy, and Iridocorneal Endothelial syndrome DSEK/DSAEK: DM & endo with a thin layer of posterior stroma DMEK/DMAEK: only DM & endo, no stroma; 748 DMEK performed in 2012 A stands for automated : using keratome to dissect Eye banks now provide pre-cut tissue for DSAEK and DMEK Descemet stripping and endothelial keratoplasty (DSEK) Descemet stripping automated endothelial keratoplasty (DSAEK) Descemet s membrane endothelial keratoplasty (DMEK) Descemet s membrane automated endothelial keratoplasty (DMAEK)

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16 ENDOTHELIAL KERATOPLASTY (EK) DSAE K DME K

17 ENDOTHELIAL KERATOPLASTY (EK) Advantages: No induced astigmatism resulting in early visual recovery and better visual outcomes. Fewer suture and wound related complications. Lower risk of other complications. Disadvantages: Suboptimum visual result unless corneal stroma is relatively free of opacity; reduced vision due to interface opacity or transplant folds in some cases Complications: Detachment in 5 30% of cases. Can be re-attached by re-injecting air. Possible pupil block following air tamponade

18 DSAEK VS DMEK Potential advantages of DMEK: faster visual rehabilitation, better visual outcomes, and lower rejection rates.

19 COMPARISON OF PK, ALK & EK PK Can be used for any indication Potentially best optical result Relatively undemanding technique ALK Minimal requirement for donor material Extraocular procedure Low risk of rejection Less topical steroid use Early suture removal safe EK Better globe integrity Fewer wound cx Faster recovery No suture-related issues Less post-op astigmatism Higher rejection rate Many complications Astigmatism common Graft-host interface limit VA Astigmatism similar to PK Dependent on endo quality Technically more difficulty Graft-host interface limit VA Rejection rate similar to PK Dependent on epi/stroma quality Long term survival unknown

20 FUTURE DIRECTIONS Descemetorhexis Without Endothelial Keratoplasty (DWEK) Rho Kinase Inhibitors

21 REFERENCES: Arenas E, Esquenazi S, Anwar M, Terry M. Lamellar corneal transplantation. Surv Ophthalmol Nov;57(6): doi: /j.survophthal Review. Tan DT, Dart JK, Holland EJ, Kinoshita S. Corneal transplantation. Lancet May 5;379(9827): doi: /S (12) Review. Price, Marianne and Price, Francis. Endothelial keratoplasty A Review. Clinical and Experimental Ophthalmology 2010, 38: Waring G, Lynn M, McDonnell P, Results of the Prospective Evaluation of Radial Keratotomy (PERK) Study 10 Years After Surgery Arch Ophthalmol. 1994;112(10): Anshu A, Price MO, Tan DT, Price FW Jr. Endothelial keratoplasty: a revolution in evolution. Surv Ophthalmol May-Jun;57(3): doi: /j.survophthal Review. Jean Y Chuo, Sonia N Yeung and Guillermo Rocha, Modern corneal and refractive procedures, Expert Rev. Ophthalmol. 6(2), (2011) Writing Committee for the Cornea Donor Study Research Group, Lass JH, Benetz BA, Gal RL, Kollman C, Raghinaru D, Dontchev M, Mannis MJ, Holland EJ, Chow C, McCoy K, Price FW Jr, Sugar A, Verdier DD, Beck RW. Donor age and factors related to endothelial cell loss 10 years after penetrating keratoplasty: Specular Microscopy Ancillary Study. Ophthalmology Dec;120(12): Writing Committee for the Cornea Donor Study Research Group, Mannis MJ, Holland EJ, Gal RL, Dontchev M, Kollman C, Raghinaru D, Dunn SP, Schultze RL, Verdier DD, Lass JH, Raber IM, Sugar J, Gorovoy MS, Sugar A, Stulting RD, Montoya MM, Penta JG, Benetz BA, Beck RW. The effect of donor age on penetrating keratoplasty for endothelial disease: graft survival after 10 years in the Cornea Donor Study. Ophthalmology Dec;120(12): Stulting RD, Sugar A, Beck R, Belin M, Dontchev M, Feder RS, Gal RL, Holland EJ, Kollman C, Mannis MJ, Price F Jr, Stark W, Verdier DD; Cornea Donor Study Investigator Group. Effect of donor and recipient factors on corneal graft rejection. Cornea Oct;31(10): Sugar A, Montoya MM, Beck R, Cowden JW, Dontchev M, Gal RL, Kollman C, Malling J, Mannis MJ, Tennant B; Cornea Donor Study Investigator Group. Impact of the cornea donor study on acceptance of corneas from older donors. Cornea Dec;31(12): Lass JH, Beck RW, Benetz BA, Dontchev M, Gal RL, Holland EJ, Kollman C, Mannis MJ, Price F Jr, Raber I, Stark W, Stulting RD, Sugar A; Cornea Donor Study Investigator Group. Baseline factors related to endothelial cell loss following penetrating keratoplasty. Arch Ophthalmol Sep;129(9): Lass JH, Sugar A, Benetz BA, Beck RW, Dontchev M, Gal RL, Kollman C, Gross R, Heck E, Holland EJ, Mannis MJ, Raber I, Stark W, Stulting RD; Cornea Donor Study Investigator Group. Endothelial cell density to predict endothelial graft failure after penetrating keratoplasty. Arch Ophthalmol Jan;128(1):63-9. Sugar J, Montoya M, Dontchev M, Tanner JP, Beck R, Gal R, Gallagher S, Gaster R, Heck E, Holland EJ, Kollman C, Malling J, Mannis MJ, Woody J; Group Cornea Donor Study Investigator Group. Donor risk factors for graft failure in the cornea donor study. Cornea Oct;28(9): Sugar A, Tanner JP, Dontchev M, Tennant B, Schultze RL, Dunn SP, Lindquist TD, Gal RL, Beck RW, Kollman C, Mannis MJ, Holland EJ; Cornea Donor Study Investigator Group. Recipient risk factors for graft failure in the cornea donor study. Ophthalmology Jun;116(6): Dunn SP, Stark WJ, Stulting RD, Lass JH, Sugar A, Pavilack MA, Smith PW, Tanner JP, Dontchev M, Gal RL, Beck RW, Kollman C, Mannis MJ, Holland EJ; Cornea Donor Study