Eyeworld

39 EW FEATURE angles are opened. "Also, we prevent the air, which will be put into the eye later on, from going behind the IOL," he said. The single-pass four-throw pupilloplasty is a simple technique of repositioning the iris structure and pupil reconstruction, which entails intertwining of thread around itself that acts as a lock mechanism and ensures non-loosen- ing of the loop. For this technique, one has to use a prolene suture. "A single pass of the 10-0 suture on a long arm needle is passed through the iris tissue followed by creation of a loop with four throws around it that slide inside the eye," Dr. Agarwal said. "This creates a helical configura- tion that prevents the suture from opening up." A knot consists of an initial approximating loop followed by a second throw of sutures that creates a securing loop. This tech- nique 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 PDEK. Dr. Agar- wal said one of the advantages of the PDEK technique is that the graft can come from a donor of any age. "The youngest we have used is a 9-month-old donor," he said. "This gives us the advantage of a better endothelial cell count from the do- nor." The second advantage of PDEK is during surgery the physician can manipulate the graft easily. These three techniques of glued IOL, single-pass four-throw pupil- loplasty, and PDEK have changed the management of pseudophakic bullous keratopathy, Dr. Agarw- al said. 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 compartmental- ization 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 fixation without pseudophacodonesis." For this reason, Dr. Agarwal said it's his preferred technique when combin- ing with PDEK. "The reason why pupilloplasty is connected to PDEK is that in eyes without a capsule and endotheli- al 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," Dr. Agarwal said. This creates absence of air in the AC in the immediate postop period. 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. EW 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 July 2018 • Challenging cases

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