CATARACT EWAP SEPTEMBER 2022 ÓÇ fact that cataract surgery has more volume than retinal and corneal surgeries put together,” Dr. Yeoh said. “This was maybe because there was a perception that modern phaco cataract surgery is so well developed that an added imaging technique like intraoperative OCT would not be useful to cataract surgeons. On the contrary, I have found that intraoperative OCT has opened up a new dimension in phaco cataract surgery.” First and foremost, Dr. Yeoh said intraoperative OCT is helpful for the teaching of trainees. Figures 5 and 6. OVD under the IOL and after OVD removal. “We are operating on a 3-D structure, and intraoperative OCT allows us to see the eye in cross section during surgery,” he said. “This leads to a better understanding and appreciation of the surgical anatomy and yuidic movements during cataract surgery. This in turn is an invaluable aid to trainee cataract surgeons who get far more information compared to just a microscopic view.” Dr. Yeoh noted how with intraoperative OCT, a trainee can see and adjust his or her technique while sculpting a groove in the nucleus (Figure 1). When inexperienced, knowing how deep to create a groove or how it should be shaped can be difficult. Dr. Yeoh said intraoperative OCT is also helpful in diagnosing a posterior subcapsular cataract vs. a posterior polar cataract (Figure 2) and showing pseudoexfoliation material on the anterior lens surface (Figure 3). He admitted that while this function “gives us pretty pictures, [it] does not always contribute to better or safer surgery.” Intraoperative OCT has helped surgeons see and better understand where the yuid planes are in hydrodissection and hydrodelineation. He said that these are brief but important steps in phaco. “In Figure 4, we can see that after hydrodissection, there is a layer of yuid behind the nucleus with a small layer of residual lens cortex still present in front of the posterior capsule. Despite our best efforts to effect cortical cleaving hydrodissection, leaving a clean posterior capsule, this is often difficult to achieve,” he said. “Hydrodelineation, which was also done in this case, results in a golden ring around a small nucleus, and this is reyected by the intraoperative OCT image of a thin line just behind the nucleus.” Intraoperative OCT can also identify if there is still OVD under the IOL (Figures 5 and 6). As a surgical aid, Dr. Yeoh shared a case where intraoperative OCT was able to detect and show a posterior capsule rupture prior to starting surgery Figure Ç®, which allowed the surgeon to modify the technique. Dr. Yeoh also shared how he was able to image patients with anterior radial tears and posterior capsule ruptures, thanks to intraoperative OCT, when corneal clarity compromised the view or was ust difficult to see. “The intact posterior capsule is transparent and difficult to see even with a microscope, and sometimes we are unsure as to whether a posterior capsule rupture has occurred,” he said. Figure 8 shows a patient who had an anterior radial tear in the capsulorhexis edge and an anterior radial tear extending posteriorly across the whole posterior capsule. “The anterior radial tear is shown by the two thick, curved lines and the posterior capsule tear by the thinner and more scrolled edges. I named this the ‘intraoperative OCT scroll sign of posterior capsule rupture,’” he said. “They behave differently because we know that the anterior capsule is thicker than the posterior.” Intraoperative OCT also came
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