Eyeworld

69 July 2018 EW MEETING REPORTER When you have patients with Fuchs' dystrophy and cataract, there are several questions to ask, she added. It's important to consider which disease is causing the symp- toms. You also have to consider the timing of the surgery; Dr. Colby often recommends earlier cataract surgery. Choosing which procedure to perform is important, as is the type of IOL used. Dr. Colby stressed the importance of assessing the risk of corneal decompensation and highlighted some of the properties of the corneal endothelium. In management of Fuchs' dystrophy, it's important to determine if the en- dothelium needs to be replaced, and Dr. Colby said that evidence from some studies suggests the endothe- lium is capable of self-regeneration. She shared a case she handled with deliberate Descemet's stripping only (DSO) of a 69-year-old man with cataract and Fuchs.' The patient had confluent central guttae with pre- served peripheral endothelium and underwent phaco/IOL plus 4 mm stripping of central Descemet's. In conclusion, she said, if the patient has mostly cataract symp- toms, you should consider phaco alone and counsel the patient regarding the visual significance of guttae and the risk of corneal decompensation. If the patient has mostly Fuchs' symptoms with minimal cataract, she recommended considering EK or DSO. Finally, Dr. Colby said that if both diseases con- tribute to the patient's symptoms, surgeons may consider phaco-EK or phaco-DSO, depending on the extent of the guttae. New methods of capsulotomy Richard Packard, MD, London, U.K., spoke about methods for creat- ing capsulotomies, highlighting the CAPSULaser (Los Gatos, California). He discussed some important points in modern day bleb differ- entiation and spoke about the XEN Gel Stent (Allergan, Dublin, Ireland) and InnFocus MicroShunt (Santen, Osaka, Japan). With adjunctive mitomycin-C, both ab interno and ab externo micro-stents appear to provide po- tency approaching that of the gold standard trabeculectomy, Dr. Ahmed said. Cataract surgery in patients with Fuchs' dystrophy Kathryn Colby, MD, PhD, Chica- go, discussed options for cataract surgery in patients with Fuchs' dystrophy. Fuchs' dystrophy is a slowly pro- gressive dysfunction of the corneal endothelium, she said. There is a decrease in cell count with abnormal shape and variation in cell size and guttae. Fuchs' patients are typically diagnosed in their 40s, with inter- vention for patients in their 60s–70s, Dr. Colby said, adding that wom- en are more commonly and more severely affected. There is also a hereditary component, and Fuchs' is the most common cause of corneal transplantation in the U.S. Up to 4% of patients in the U.S. have guttae with this condition, and the guttae are associated with visual dysfunc- tion. Dr. Colby discussed how cataract surgery can be handled in Fuchs.' Abnormal Descemet's membrane in Fuchs' is prone to detachment, she said, so it's import- ant to be aware of this. A near-clear incision may reduce endothelial cell loss. Additionally, a soft shell viscoelastic technique (dispersive viscoelastic against the endothelium to protect it and cohesive viscoelas- tic beneath) can be used. Dr. Colby said to be parsimonious with phaco power. may be more "floppy" and apt to unfold spontaneously. In discussing some of the possi- ble graft configurations, Dr. Majmu- dar noted that the double scroll with the endothelium outward would be the ideal configuration. He present- ed maneuvers to unfold the graft. Keeping the anterior shallow in these maneuvers is very important. Which maneuver you choose may depend on the floppiness or tight- ness of the scroll. Dr. Majmudar spoke about using gentle taps on the corneal surface for a typical double scroll, the Dirisamer two-cannula technique, which involves holding one leaflet of the graft in position with external pressure from a cannula while the other cannula sweeps aqueous across the surface of the graft and unfolds it, the use of a PDEK graft, which is slightly floppier and includes Dua's layer, which prevents the graft from scrolling tightly, and the Dapena bubble rolling technique, which uses a very small air bubble on top to push on the edges of the graft. Dr. Majmudar said that a combination of techniques can sometimes be required, especially when there is a tight scroll. Remember that air is a barrier, he added. Office-based glaucoma technologies, blebs, and more Iqbal "Ike" Ahmed, MD, Toronto, Canada, discussed bleb strategies. He stressed that a posterior bleb is desirable because there are fewer metabolically active cells and it is away from the limbal stem cells. A posterior bleb is also less prone to ocular surface trauma/issues and has protection under the upper lid. You can access more conjunctival lym- phatics, and there are fewer Tenon's attachments. The posterior bleb of- fers improved patient comfort. All of these factors offer the potential for a better bleb, Dr. Ahmed said. IOP should be in the physiologic range prior to air injection into the stroma. He suggested using a blunt- tipped air cannula with a port that faces downward. Pass the needle or cannula at 80–90% of the corneal depth, Dr. Reidy said, adding that you should perform the paracentesis after achieving the big bubble. If you don't achieve it on the first try, go to another area and try again, he said. Parag Majmudar, MD, Chicago, shared tips and tricks for Descemet's membrane endothelial keratoplasty (DMEK) unfolding. Over the past 10–12 years, there has been a shift away from penetrating keratoplas- ty to lamellar techniques, he said. Posterior lamellar techniques are providing faster visual rehabilitation than penetrating keratoplasty, he noted. He mentioned the evolution in endothelial keratoplasty from DLEK to DSAEK to DMEK to PDEK. There have been some dramatic improve- ments along the way. However, he noted that there are still barriers in adopting DMEK. With availability of pre-loaded DMEK tissue, some of the barriers are lifted, Dr. Majmudar said, but there is still fear about how to unfold the graft. The key point is to understand how to manipulate the graft from outside the eye using fluidic forces within the anterior chamber, he said. The most important criteria for graft unfolding is to have a shallow anterior chamber, Dr. Majmudar said. This is accomplished by digital pressure or releasing fluid from the eye via the paracentesis. Once the chamber shallows, the graft will flat- ten; reforming the chamber allows the graft to scroll up again. Dr. Majmudar also noted some graft characteristics that could influence how well a graft unfolds. In donors younger than 40, the graft has a tendency to form a tight scroll. In donors older than 40, the graft continued on page 70

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