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CATARACT & REFRACTIVE TODAY EUROPE &REFRACTIVE SURGERY BY PRIYANARANG,MS;ANDAMARAGARWAL,MS,FRCS,FRCO scroll upasmuch. tissue thanwitholder;anadditionallayerinPDEKdonortissue,thegraftdoesnot After PDEK,eyeswithscarredcorneastendtohealfasterandbetteryoungdonor 30-gauge needle attached to a 5-mL air-filled syringe and GRAFT CREATIONANDINSERTION Descemet membrane endothelial keratoplasty (DMEK). graft and outline the benefits of the procedure compared with graft visualization, and adhesion. the method of graft preparation, donor lenticule insertion, undergone multiple iterations, including improvements in we started performing PDEK in 2013, this technique has Nottingham, United Kingdom (see FRCS, FRCOphth, FEBO, MD, PhD, of the University of nally defined by Harminder Dua, MBBS, DO, MS, MNAMS, NOT TO SCROLLTONOT ORSCROLL TO To create the graft for PDEK (Figure 1), we take a In this article, we review how to create and insert the PDEK •  •  •  with the glued IOL technique can help to optimize the with thegluedIOLtechniquecan helptooptimizethe scroll becauseofthesplintingeffectPDL. infant donorcorneas,andthegraftdoesnotcurl combined PDEK and glued IOL procedure. combined PDEKandgluedIOL procedure. globe collapseandfacilitatesgraft adherenceinthe patient’s visualpotential. The double infusion cannula technique helps prevent The doubleinfusioncannulatechnique helpsprevent In aphakiceyesorwithmalpositionedIOLs,PDEK The PDEKprocedureallowstheuseofyoungand AT A GLANCE (PDL), or Dua layer, of the pre-Descemet layer the theory and description plasty, has evolved based on area of endothelial kerato latest development in the keratoplasty (PDEK), Pre-Descemet endothelial

The Dua Layer |

SEPTEMBER 2017 ). Since 2 origi 1 the - - injected into the donor lenticule, and a type 1 big bubble lenticule with the endothelial side up. Air is then slowly midperiphery of the corneoscleral rim of a donor cornea insert it from the edge of the corneoscleral rim up to the the bubble is punctured, and trypan blue dye is injected to used for DMEK. is missing from the graft. However, this tissue can still be achieved, PDEK cannot be performed because the PDL (DM)-endothelium complex. When a type 2 bubble is air is between the PDL and the Descemet membrane then often a type 2 big bubble is created, mately 7 to 8 mm in diameter. midperiphery. The bubble is dome-shaped and approxi is created, which characteristically spreads from center to

with corneoscleral scissors, and the graft is harvested (F). with corneoscleral scissors, and the graft is harvested (F). is injected to stain the bubble (E). The bubble is cut all around bubble is punctured with a sideport blade (D). Trypan blue dye shaped appearance is seen (C). The extreme periphery of the (B), and then a type 1 big bubble with characteristic dome- starts to form from the center, extending to the midperiphery Small bubbles are initially formed (A). A type 1 big bubble rim to the corneal midperiphery, and air is slowly injected. to a 5-mL air-filled syringe is introduced from the corneoscleral Figure 1. PDEK graft preparation. A 30-gauge needle attached Once the bubble is created, the extreme periphery of If air is not injected into the correct plane by the needle, D A phth B E C F 3 indicating that - CORNEA

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NOW Also known as known Also the layer pre-Descemet Serves as demarcating the of a creation the line for graftPDEK graftThe typically involves Descemet Duathe layer, themembrane, and as a singleendothelium entity THE DUA DUA THE LAYER • • • CATARACT & REFRACTIVE SURGERY TODAY EUROPE

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WATCH IT WATCH SEPTEMBER 2017 http://bit.ly/agarwal0917 During descemetorrhexis, the air infusion is switched on, switched is infusion air the descemetorrhexis, During Initially, the fluid infusion cannula is placed at the pars planapars the at placed is cannula infusion fluid the Initially, comple After executed. is technique IOL glued the while cannulaanother place we procedure, IOL glued the of tion maintainer. chamber anterior an as act to trocar a through theto connected is maintainer chamber trocar–anterior The deliv cannula the and (Alcon), System Vision Constellation facilitateto chamber anterior the inside air pressurized ers procedure. PDEK the removed. is complex DM-endothelium diseased the and inject then is it and loaded, been has graft the Meanwhile, infu air the point, this At chamber. anterior the inside ed into seeping fluid of wave light the and off, switched is sion infusion placed posteriorly the from chamber anterior the simulta and depth chamber the maintain to helps cannula graft. the of unrolling the facilitates neously outcomes of glued IOL fixation with PDEK. A video ofvideo A PDEK. with fixation IOL glued of outcomes http://bit.ly/agarwal0917.at viewed be can technique the ------

C In this procedure, a procedure, this In 6 B The intrascleral tuck of the haptics and seal and haptics the of tuck intrascleral The 4,5 A We have also started using a double infusion cannula infusion double a using started also have We We often perform pupilloplasty, which prevents the prevents which pupilloplasty, perform often We In aphakic eyes, it is essential to perform secondary IOL secondary perform to essential is it eyes, aphakic In The recipient bed is prepared in exactly the same mannersame the exactly in prepared is bed recipient The fixation and single-pass, four-throw pupilloplasty (B). At(B). pupilloplasty four-throw single-pass, and fixation (C). seen is graft corneal clear the postoperative, months 2 Figure 2. PDEK with glued IOL in scarred cornea with single- with cornea scarred in IOL glued with PDEK 2. Figure Preoperativepupilloplasty. pupilloplasty four-throw pass, IOLglued with PDEK after weeks Two (A). cornea scarred one for infusion fluid—are placed to optimize the surgicalthe optimize to placed fluid—are infusion for one donor graft is increased. is graft donor andair cannulas—onefor infusion two which in technique, of the knot rubbing against the donor graft. This is espe is This graft. donor the against rubbing knot the of chamber, anterior shallow a with eyes in important cially the against rub to suture the of propensity the which in apposing the iris tissue. In single-pass, four-throw pupillo four-throw single-pass, In tissue. iris the apposing loop approximation the formed, is knot no because plasty, has This iris. the to fashion parallel a in lies suture the of chance no virtually is there that advantage additional the is threaded through the iris leaflets that are to be apposed. be to are that leaflets iris the through threaded is The taken. are throws four and withdrawn, is loop a Then eye, the inside slips loop the and pulled, are ends suture all of these cases, we perform the single-pass, four-throw four-throw single-pass, the perform we cases, these of all 2). (Figure technique pupilloplasty needle the of arm long the to threaded suture nylon 10-0 escape of air into the vitreous cavity, helps to maintain to helps cavity, vitreous the into air of escape positive a as acts also and depth, chamber anterior the In bed. recipient the against graft the pushing by factor ing of the flaps with helps to achieve stable achieve to helps glue fibrin with flaps the of ing fixation. IOL when this is done, the IOL helps to compartmentalize to helps IOL the done, is this when proce the us, For chambers. posterior and anterior the IOL glued the is fixation IOL secondary for choice of dure technique. APHAKIC EYES procedure; keratoplasty endothelial the before fixation pushes the donor tissue against the recipient bed and facili and bed recipient the against tissue donor the pushes adherence. graft tates donor lenticule is then loaded into a foldable IOL cartridge,IOL foldable a into loaded then is lenticule donor orienta correct confirm we After injected. is graft the and Thistissue. donor the beneath injected is air graft, the of tion is harvested. is performed,is descemetorrhexis A procedure. DMEK a in as The removed. is complex DM-endothelium diseased the and stain the graft. With the help of corneoscleral scissors, we scissors, corneoscleral of help the With graft. the stain graft the and edge, peripheral the along graft the cut then CORNEA 40

CATARACT & REFRACTIVE SURGERY TODAY EUROPE CATARACT &REFRACTIVE SURGERY those that we felt preoperatively would be impossible to tissue. We have observed this in many cases, including to heal faster and better than it does with older donor formed with young donor tissue, the recipient eye tends that, in eyes with scarred corneas in which PDEK is per rable between DMEK and PDEK. CONCLUSION minimal instrumentation. PDEK. In PDEK, the donor tissue can be obtained with automated endothelial keratoplasty are not needed for donor lenticule for ultrathin DSEK or Descemet-stripping expensive microkeratomes that are essential to obtain a lates to early clearance of stromal tissue. Moreover, the donor stroma is transplanted, which theoretically trans or ultrathin DSEK. This means that a smaller amount of in Descemet-stripping endothelial keratoplasty (DSEK) mately 30 to 35 µm, which is thinner than the grafts used PDEK to a DMEK. sions help to avoid the need to convert from a planned tissue are minimized (http://bit.ly/2agarwal0917). The adhe creation of a type 2 bubble with the use of young donor sions between the DM and the PDL, chances of accidental PDL acts as a splint. Due to the presence of strong adhe donor tissue, however, the graft does not scroll as much; the the eye. With the PDL serving as an additional layer in PDEK edges become scrolled, they can be difficult to unfold inside grafts from younger donors tend to curl up, and, once the limited to those older than age 40 years. This is because the prospective pool of donors, which for DMEK is usually donor. est tissue that we have used came from a 9-month-old corneas can be used in the former procedure. The young YOUNG DONORCORNEA cavity helps to prevent globe collapse. gery. Placing the infusion fluid cannula into the vitreous reflects the outcomes of the endothelial keratoplasty sur the absence of posterior segment infusion, and this directly tion in the eye. Aphakic eyes are prone to globe collapse in lenge of fixating an IOL and handling the risk of inflamma to the recipient eye. This is in addition to the existing chal challenge to unfold the graft and have it achieve adherence against the host cornea and promotes graft adherence. 30 to 45 seconds. This vaults and pushes the donor graft ent bed. A steady pressure of 50 mm Hg is maintained for anterior chamber helps the graft to adhere to the recipi sion is switched on again, and the air pressure inside the Studies have shown that endothelial cell loss is compa The average thickness of the graft in PDEK is approxi An advantage of PDEK over DMEK is that young donor In aphakic and previously vitrectomized eyes, it can be a Once the graft is correctly unrolled, the pressurized infu 8 The ability to use this young donor tissue expands 9 Also, we have noticed

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SEPTEMBER 2017 SEPTEMBER ------7. AgarwalA,NarangP,KumarDA,A.Trocaranteriorchambermaintainer:improvisedinfusiontechnique. 6. NarangP,AgarwalA.Single-passfour-throwtechniqueforpupilloplasty. with pupilloplastyandpre-Descemetsendothelialkeratoplasty:atripleprocedure. 5. NarangP,AgarwalA,DuaHS,KumarDA,JacobS,A.Gluedintrascleralfixationofintraocularlens eyes withdeficientposteriorcapsules. 4. AgarwalA,KumarDA,JacobS,etal.Fibringlue-assistedsuturelessposteriorchamberintraocularlensimplantationin plasty. 3. DuaHS,KatamishT,SaidDG,FarajLA.Differentiatingtype1from2bigbubblesindeepanteriorlamellarkerato layer). 2. DuaHS,FarajLA,SaidDG,GrayT,LoweJ.Humancornealanatomyredefined.Anovelpre-Descemet’slayer(Dua’s 1185. 1. AgarwalA,DuaHS,NarangPetal.Pre-Descemet’sendothelialkeratoplasty(PDEK). reason remains unclear. of these young donor corneas. Currently, however, the presence of stem cells or some other factor in the stroma cedure. treat successfully with an endothelial keratoplasty pro org/10.1016/j.jcjo.2017.03.004. with epithelialdebridementforchronicpseudophakicbullouskeratopathy. 10. AgarwalA,NarangP,KumarDA,A.Youngdonor–graftassistedendothelialkeratoplasty(PDEK/DMEK) pneumodissection forendothelialkeratoplasty:anexvivostudy. 9. AltaanSL,GuptaA,SidneyLE,ElalfyMS,AgarwalDuaHS.Endothelialcelllossfollowingtissueharvestingby a prospectiveanalysis. 8. AgarwalA,NarangP,KumarDA,JacobS.Pre-Descemetendothelialkeratoplastywithinfantdonorcorneas: Cataract RefractSurg n n n Priya Narang, MS n n n , MS, FRCS, FRCOphth Clin Ophthalmol.     Centre, ,. Financial interest:Noneacknowledged [email protected] Director, NarangEyeCare&LaserCentre, Ahmedabad,India Financial interest:Noneacknowledged [email protected] Professor andHead,Dr.Agarwal’sEyeHospital&Research http://bit.ly/2agarwal0917 10 We believe that the reason for this may be the . 2016;42(2):185-189. . 2013;120(9):1778-1785. Cornea WATCH IT 2015;9:1155-1157. . 2015;34(8):859-865. JCataractRefractSurg n . 2008;34(9):1433-1438. Br JOphthalmol. Can JOphthalmol Eur JOphthalmol 2015;99(5):710-713. Cornea NOW Br JOphthalmol. . 2015;34(12):1627-1631. . Inpress.doi:http://dx.doi. . 2017;27(4):506-508. 2014;98(9):1181- - J -