Eyeworld

66 | EYEWORLD | FALL 2024 C ORNEA Relevant disclosures Price: RxSight Syed: None to weeks after endothelial cells cover areas that were damaged. When evaluating corneal edema after cataract surgery, Dr. Syed measures central corneal thickness with a pachymeter at the first postoperative visit to record a baseline against which to compare follow-up evaluations. "While specular microscopy may be helpful in confirm- ing endothelial cell loss, I do not always find it helpful in the setting of significant corneal edema because the measurements are often unreliable," she said. "Another test I may use is anterior segment optical coherence tomog- raphy (AS-OCT), especially in cases where the edema may be focal. I have evaluated cases of persistent postoperative corneal edema that were actually Descemet's membrane detach- ments that we identified on AS-OCT, and these cleared up with placement of an air bubble in the anterior chamber and face-up positioning by the patient. Identification of this diagnosis may prevent the patient from undergoing an unnec- essary corneal transplant." When managing postoperative corneal edema, Dr. Syed keeps two goals in mind. The first is to eliminate aggravators of endothelial compromise, and the second is to treat corneal edema itself. In cases of immediate postoper- ative corneal edema, Dr. Syed said inflamma- tion from surgical trauma often contributes to endothelial dysfunction. Topical steroids reduce inflammation as well as corneal edema in these situations. In the presence of a quiet eye, a steroid does not usually provide any direct benefit, instead causing side effects such as increased intraocular pressure. Another approach to med- ical management includes hypertonic saline, which accelerates corneal deturgescence. This treatment does not directly promote endothelial viability, she said, but rather provides symp- tomatic relief. Hypertonic saline works well in mild edema but not as well in advanced cases. Patients should be counseled on the likelihood of long-term hypertonic saline therapy if the goal is to avoid endothelial keratoplasty. Dr. Syed noted that rho kinase (ROCK) inhibitors are an alternative approach to man- age postoperative corneal edema. The ROCK pathway plays a role in regulating endothelial cell migration, proliferation, and adhesion, and ROCK inhibitors support endothelial wound healing and accelerate corneal deturgescence after surgery. 6 Options for ROCK inhibition include netarsudil 0.02% and ripasudil 0.4%. Both formulations may improve endothelial cell viability after surgical trauma. "I typically use the ROCK inhibitor 4 times daily for 4–6 weeks postoperatively or until corneal deturgescence is noted, although I will titrate based on tolerabil- ity," she said. If edema persists a couple of months out, Dr. Price said there's a good chance it's not going to clear and to consider an endothelial keratoplasty. For a non-Fuchs patient, he'll do cataract surgery alone when there's a low cell count because if you use a good technique, the patient can maintain a low cell count for years with or without a previous graft. Fuchs is a different story. The guttae affect vision, he said. "I operate on people with no apparent edema but who have guttae caus- ing glare and haze, and we see improvements for those patients." If they have guttae and a cataract, Dr. Price recommends treating both at the same time. Patients can have some improve- ment from just treating the cataract, but often, that may lead to corneal decompensation. When explaining guttae to patients, Dr. Price likens them to raindrops on a windshield. A few scattered guttae don't noticeably de- grade vision, but as you get more, they start to affect vision. Like raindrops, guttae cause light scattering. If there are significant guttae over the pupillary area, he'll typically do a combined case with cataract and DMEK, Dr. Price said. "That said, it's harder to hit the refractive target with the IOL because the guttae and clinical- ly evident or sub-clinical edema associated with Fuchs dystrophy throw off the accuracy of biometry. Even when preoperative corneal edema is not discernible by slit lamp exam, we notice that the central corneal thickness usually decreases after DMEK in eyes with Fuchs dys- trophy, and those changes affect the refractive accuracy," he said. Dr. Price recommends three options to pa- tients with cataracts and Fuchs: 1. Do a combined case with a standard monofocal lens. Most patients do well, but the final postoperative spherical equivalent can range –2 to +3 D from the target, and that's a big range because with standard cataract surgery, most fall within ±0.5 D of the target. A high degree of refractive accuracy is required for satisfactory use of a continued from page 65 Contact Price: fprice@pricevisiongroup.net Syed: zsyed@willseye.org

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