EyeWorld India September 2019 Issue

EWAP SEPTEMBER 2019 59 CORNEA by Maxine Lipner EyeWorld Senior Contributing Writer What’s new in corneal transplantation Contact information Gupta: GUPTAN@smh.ca This article originally appeared in the May 2019 issue of EyeWorld . It has been UNKIJVN[ OQFKƂGF CPF CRRGCTU JGTG YKVJ permission from the ASCRS Ophthalmic Services Corp. C orneal transplant techniques continue to evolve. In a recent study, 1 University of Toronto investigators examined the types of transplant surgeries performed and found that partial thickness transplants accounted for 85% of all of their current graft procedures, according to Neeru Gupta, MD. This was up from about 65% a few years earlier. The study initially looked at 2012 when the University of Toronto centralized all of the corneal transplants, which had been at multiple teaching hospitals, into a single center at the Kensington Eye Institute. The idea was to look at current indications and approaches to corneal transplantation during ̅i wÀÃÌ Þi>À° º/…ˆÃ Ü>à >Ì > ̈“i when partial thicknesses were Ì>Žˆ˜} œvv]» À° Õ«Ì> Ã>ˆ`° º7i found that a failed graft was the most common indication for full thickness transplant but that partial thickness accounted for two-thirds of all procedures.” 2 A few years later, investigators decided to take another look and see where procedures stood. The investigation considered the period from January 2014 to December Óä£È] À° Õ«Ì> Ã>ˆ`° º7…i˜ we looked at the initial 2012 to 2013 data, we found that the number one partial thickness procedure was DSAEK,” she Ã>ˆ`° º ÕÌ Ü…i˜ Üi `ˆ` ̅i ˜iÜ study, we found that DMEK had emerged as the procedure of choice.” This was something D r. Gupta has neatly summarized the recent evolution in corneal transplantation, with the experience of the University of Toronto— ˆ˜ 7iÃÌiÀ˜ `iÛiœ«i` VœÕ˜ÌÀˆiÃ] ÃÌ>˜`>À` «i˜iÌÀ>̈˜} ŽiÀ>̜«>ÃÌÞ (PK) has largely been replaced by endothelial keratoplasty (EK) procedures for corneal endothelial dysfunction, and while DSAEK remains dominant, DMEK, a more challenging procedure, is gradually on the rise. ˜ ƂÈ>] ܈̅“œÀi LՏœÕà ŽiÀ>̜«>Ì…Þ ® >˜` “œÀi >Ìi‡ÃÌ>}i disease, PK still remains the commonest procedure, and while the ÌÀ>˜ÃˆÌˆœ˜ vÀœ“ * ̜ ˆÃ i˜ÃՈ˜}] ̅ˆÃ ˆÃ “œÃÌÞ Vœ˜w˜i` ̜ “œÀi developed Asian cities. For example, recent data from our main Asian corneal transplant registry, the Singapore Corneal Transplant Registry (SCTR), shows that in 2018, PKs only accounted for 17% of transplants, while DSAEK (36%), DALK (25%), and DMEK (22%) accounted for the rest. In SCTR, DMEK is also on the rise, albeit more slowly, partly because “œÃÌ œv œÕÀ V>Ãià >Ài ˆÃ “œÀi V…>i˜}ˆ˜} ̜ «iÀvœÀ“ ˆ˜ compared to Fuchs’ dystrophy). Dr. Gupta’s article stated that we need to determine if DMEK impacts favorably on long-term outcomes—it `œià ˆ˜`ii`° 7i…>Ûi ÕÃÌ «ÕLˆÃ…i` >˜ >À̈Vi Vœ“«>Àˆ˜} œ˜}‡ÌiÀ“ graft survival and complications between 405 PKs, 423 DSAEKs, and £Ó£ à «iÀvœÀ“i` vœÀ >˜` ÕV…ý `ÞÃÌÀœ«…Þ° 1 The 5-year survival for the DMEK group was statistically better than DSAEK and PK (p<0.001) with cumulative survival rates of 97.4%, 78.4%, and 54.6% for DMEK, DSAEK, and PK, respectively. In Fuchs’ dystrophy cases, DMEK and DSAEK had statistically similar survival rates of 98.7% and 96.2%, LÕÌ LœÌ…ÜiÀi LiÌÌiÀ ̅>˜ * >Ì Çΰx¯ «rä°ä䙮° ˜ ] }À>vÌ ÃÕÀۈÛ> was poorer overall compared to Fuchs’ dystrophy, but DMEK graft survival (94.7%) was again better than DSAEK (65.1%) and PK (47.0%) (p=0.001). Eyes which underwent DMEK had the lowest rate of graft ÀiiV̈œ˜ £°Ç¯ Ûð -Ƃ x°ä¯ Ûð * £{°£¯] «ä°ä䣮 >˜` > œÜiÀ incidence of postoperative elevation of intraocular pressure (11.6% vs. DSAEK 23.6% vs. PK 22.5%, p=0.015). DMEK was clearly better in our Asian eyes. Our SCTR studies in Singapore have shown that EK surgery is clearly better than PK in Asian eyes, and that while DMEK and DSAEK appear to have equally good outcomes in Fuchs’ dystrophy, DMEK appears to Li ÃÕ«iÀˆœÀ ˆ˜ ˆ˜ ̅i ƂÈ>˜ ÃiÌ̈˜}° /…i V…>i˜}i ̅i˜ ˆÃ vœÀ œÌ…iÀ Asian countries to adopt more DSAEK and DMEK into mainstream corneal transplantation practices, which is now certainly happening. Reference £° 7œœ ] iÌ >° iÃVi“iÌ i“LÀ>˜i ˜`œÌ…iˆ> iÀ>̜«>ÃÌÞ ÛiÀÃÕà Descemet Stripping Automated Endothelial Keratoplasty and Penetrating Keratoplasty. Am J Ophthalmol . 2019 Jun 19. Epub ahead of print. Editors’ note: Dr. Tan holds a patent and receives royalties for the Endoglide FGXKEG 0GVYQTM /GFKECN 2TQFWEVU 7- WUGF KP &5'- CPF &/'- UWTIGT[ Donald Tan, MBBS, FRCS(G), FRCS(Ed), FRCOphth, FAMS Ƃ`Õ˜VÌ *ÀœviÃÜÀ Senior Visiting Consultant, Cornea & External Eye Disease Department Singapore National Eye Centre ££ /…ˆÀ` œÃ«ˆÌ> ƂÛi˜Õi] -ˆ˜}>«œÀi £ÈnÇx£ donald.tan.t.h@singhealth.com.sg ASIA-PACIFIC PERSPECTIVES continued on page 62