EyeWorld Asia-Pacific September 2018 Issue

22 EWAP FEATURE September 2017 “Visualization for the surgeon is also badly affected,” Dr. Agarwal said. “The problem in handling these cases is that we have to do multiple procedures at one time.” The IOL has to be fixed, vitrecto- my done, and the cornea replaced. Dr. Agarwal’s technique is to do a glued IOL, a single-pass four- throw pupilloplasty, and pre-De- scemet’s endothelial keratoplasty (PDEK). For the glued IOL, Dr. Agarwal said the first step is to check the IOL. The patient may be aphakic or the IOL decentered or an AC IOL implanted. If it is an AC IOL that should be explanted and if a three-piece IOL is subluxated in the eye, the same IOL can be refixed with the glued IOL tech- nique. This has now compartmen- talized the eye into the anterior and posterior segment. If the existing IOL is in a good position, it can be left behind. The second part of his man- agement strategy is to do a single- pass four-throw pupilloplasty. The idea here is a closed angle second- ary glaucoma that gets corrected as the angles are opened. “Also, we prevent the air, which will be put into the eye later on, from go- ing behind the IOL,” he said. The single-pass four-throw pupilloplas- ty is a simple technique of reposi- tioning the iris structure and pupil reconstruction, which entails in- tertwining of thread around itself that acts as a lock mechanism and ensures non-loosening of the loop. Among various techniques that have been described for pupil reconstruction, single-pass four-throw is one of the newer techniques that can be employed, he said. One has to use a prolene suture. “As the name suggests, a single pass of the 10-0 suture on a long arm needle is passed through the iris tissue followed by crea- tion of a loop with four throws around it that slide inside the eye,” Dr. Agarwal said. “This creates a helical configuration that prevents the suture from opening up.” A knot consists of an initial approxi- mating loop followed by a second throw of sutures that creates a securing loop. This technique employs the creation of only the initial approximating loop but is comprised of four throws, thereby creating an intertwining of sutures that has a self-locking mechanism and prevents loosening of the suture loop, Dr. Agarwal said. The final step is to do PDEK. Dr. Agarwal said that one of the advantages of the PDEK technique is that the graft can come from a donor of any age. “The young- est we have used is a 9-month-old donor,” he said. “This gives us the advantage of healthier and better endothelial cell count from the donor.” The second advantage of PDEK is during surgery the physi- cian can manipulate the graft easily. These three techniques of glued IOL, single-pass four-throw pupilloplasty, and PDEK have changed the management of pseudophakic bullous keratopathy, Dr. Agarwal said. This technique can be particularly valuable to surgeons. In aphakic eyes, a loss of bicamerality of the eye occurs that leads to posterior migration of the air bubble used for attaching the PDEK graft, he said. This increases the risk for a postoperative partial or total graft detachment, forward bowing of the iris, iris-graft touch, and graft dislocation into the vitreous, all of which can necessi- tate secondary procedures such as refloating, rebubbling, vitrectomy, and AC formation, which increases graft endothelial cell loss. “An effective compartmentali- zation of the eye can be obtained through the glued IOL technique,” Dr. Agarwal said. “The glued IOL offers advantages of posterior chamber IOL placement, ease of centration, [and] scleral fixation, as well as stable and sturdy fixa- tion without pseudophacodone- sis.” For this reason, Dr. Agarwal said it’s his preferred technique when combining with PDEK. “The reason why pupilloplasty is connected to PDEK, or for that matter any endothelial kerato- plasty technique, is that in eyes without a capsule and endothelial damage, one performs a glued IOL procedure,” he said. The pupil might be distorted and mydriatic. “The air, when infused in the AC for the PDEK graft fixation, goes into the vitreous cavity postop- eratively,” Dr. Agarwal said. This creates absence of air in the AC in the immediate postoperative pe- riod. It is essential for the air to be in the AC to keep the PDEK graft attached. The main purpose of the sin- gle-pass four-throw pupilloplasty is that once the pupil is made miotic, the air remains in the AC and does not migrate to the vitreous cavity, Dr. Agarwal said. This then helps the graft remain attached with a good air fill in the AC. EWAP Editors’ note: Drs. Agarwal and Chan have no financial interests related to their comments. Contact information Agarwal: aehl19c@gmail.com Chan: clara.chan@gmail.com Challenging...refractive surgery – from page 21 8