Eyeworld

81 June 2017 EW MEETING REPORTER Dr. Walter then stressed a number of things to consider when combining procedures. First, he said it's important to know how the view will be during surgery. Severe edema may obscure the view. "You need to consider astigmatism manage- ment because the incision is a little larger," he added. Accurate Ks and IOL selection are also important to consider. "You can keep the pupil dilated after the phaco," Dr. Walter said, adding that the surgeon can easily plan for topical anesthesia for a combined procedure. Meanwhile, Dr. Daluvoy argued that "less is more," sharing her reasons for separate procedures. A staged procedure means less surgery time, less risk of IOL instability, less risk of DSEK/DMEK graft complica- tions, less special positioning, and less risk of rejection. Maybe you just need cataract surgery, Dr. Daluvoy said, adding that it's possible to perform an "endothelial-friendly" cataract sur- gery. With no EK needed, this would mean no risk of rebubbling and no risk of rejection. Dr. Walter noted that when the cataract is done first, you make the patient's vision worse either imme- diately or in the near future. You could also cause the patient unnec- essary pain or an infection from ruptured bullae. When Descemet's stripping endothelial keratoplasty (DSEK) or Descemet's membrane endothelial keratoplasty (DMEK) is done first, Dr. Walter said you aren't doing the patient any favors with that either. This could still result in cataract formation and a risk for graft failure from the additional ultrasound trau- ma to the new graft. Dr. Walter stressed that there are many advantages of combined procedures. Combining can save the patient and family an extra trip to the OR. There is also faster visual re- covery with a combined procedure. Dr. Walter noted that you can use the same incision for both proce- dures, you just have to slightly en- large it. It's easy to accomplish both procedures with minimal additional instrumentation or skill. It also saves OR time when combined versus two separate events, he added. posterior corneal curvature using a population average of the posterior to the anterior, and using that to cal- culate total corneal cover. However, there are atypical cor- neas—after refractive surgery, after keratoplasty, ectasia, and with toric IOLs—in which the extrapolation can cause larger errors. Accurate measurement of the posterior cornea can be done with tomography—with Scheimpflug technology and with OCT devices —or directly with the Cassini LED topographer (i-Optics, The Hague, the Netherlands). "The concept is you measure the posterior cornea on an elevation- based method, you add that to the anterior, and you get total corneal power," Dr. Koch said. Dr. Koch said as corneas get better—and less RK is used—then measures of the posterior cornea should improve. Other continuing measurement challenges include patients with keratoconus, post-DSEK, and astig- matism. "The steeper the front, the more the back counteracts it," Dr. Koch said. Editors' note: Dr. Koch has financial in- terests with Alcon (Fort Worth, Texas), Johnson & Johnson Vision (Santa Ana, California), Bausch + Lomb (Bridge- water, New Jersey), Clarity Medical Systems (Pleasanton, California), and other companies. Cornea Day features point- counterpoint discussions Keith Walter, MD, Winston- Salem, North Carolina, and Melissa Daluvoy, MD, Durham, North Carolina, spoke on either side of "Fuchs' Dystrophy and Cata- ract: Combined EK Triple vs. Staged Procedure." First, Dr. Walter argued for a combined procedure, which he said makes life easier for everyone. Dr. Moster said researchers and engineers are currently working with the sensor in mouse eyes, which she noted is 5 µl, 1/10th the volume of a single drop, significantly less than the human eye. Dr. Moster envisioned this sen- sor being attached, for example, to a capsular tension ring or even a MIGS implant. If the latter, not only could the procedure lower pressure but the physician could accurately know, via the sensor's measurements, what happens with IOP moving forward. Taking it a step further, what if a drug delivery system were added to the sensor? Dr. Moster asked. "If these devices were able to be combined with a drug delivery system that was attached to the static [MIGS] device, the intraocu- lar pressure, when elevated, would be able to be responded to in real time," she said. In other words, communication between the sensor on the MIGS implant with a pump could release nanoparticles of medication when IOP is elevated. "Sensors will change the way everyone in this room will practice within the next few years. We will better understand glaucoma and better understand how we treat patients," Dr. Moster said. Editors' note: Dr. Moster has financial interests with Qura. Steinert Refractive Lecture Refractive Day included the first Steinert Refractive Lecture, which was delivered by Douglas Koch, MD, Houston, on the challenges of IOL calculations with postop and ectatic corneas. Dr. Koch noted that current lim- itations have left surgeons making many assumptions about posterior corneal power. Surgeons can better factor in the posterior cornea by measuring it in very limited zones, extrapolating continued on page 82 View videos from ASCRS•ASOA Los Angeles: EWrePlay.org Christopher Starr, MD, discusses results of his study of advanced diagnostics for ocular surface disease in patients undergoing cataract surgery.

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