Eyeworld

105 EW RESIDENTS October 2018 weeks to fix it so the capsular bag can contract a little. If you fix them right away, there's a greater chance they'll reoccur and you're back to where you started. … If you place a CTR you also reduce the risk of the lens rotating again," Dr. Safran said. "If you are going to rotate the lens and you do it before 5–6 weeks, you might want to put a CTR in because otherwise there is going to be a good chance of that lens rotating again." When rotating a patient at day 1 postop, Dr. Safran said he doesn't use software, sticking with rotating them back to where the original operative plan had intended. If you wait 5–6 weeks before rotating, how- ever, he recommended the Barrett Rx formula or astigmatismfix.com. He pointed out that fibrosis should be considered, even if rotation is oc- curring at the 1-month mark. Free- ing up the haptics and recognizing the common points of adhesion that are specific to the IOL is important, he said, but noted that there won't be any fibrosis if rotation occurs within 1–2 days postop. Dr. Safran said he will always reposition off-axis lenses vs. correct- ing residual astigmatism with a laser, provided the patient has not had a YAG laser posterior capsulotomy. If he finds the wrong toric power al- together was used, he will exchange the lens. "To me, to change the cornea to compensate for a rotated lens is not the right way to fix it because you're compensating in a way that I don't think is going to provide as good of a refractive outcome as to fix the problem directly," he said. EW Reference 1. Ma JJ, Tseng SS. Simple method for ac- curate alignment in toric phakic and aphakic intraocular lens implantation. J Cataract Refract Surg. 2008;34:1631–6. Editors' note: Dr. Safran and Baartman have no financial interests related to their comments. Contact information Baartman: brandon.baartman@vancethompsonvision. com Safran: safran12@comcast.net significant amount that can't be eas- ily corrected with an LRI. If I have a patient with a 29–30 mm eye and they're with-the-rule and the Barrett formula is telling me to put in a low power toric, I tend to avoid that because I don't think it's worth the risk of rotation to correct a diopter of astigmatism, which I can correct with an LRI. If, on the other hand, a higher power toric is called for, we are more likely to use it." In addition to considering placement of a CTR, Dr. Baartman noted several other intraoperative pearls to help reduce the risk of lens rotation. One is diligent removal of all viscoelastic from the capsu- lar bag, including behind the lens. Another is nailing the capsulotomy to ensure 360 degrees of capsular overlap with the optic because it's thought increased contact helps pre- vent lens tilt and rotation postop, Dr. Baartman said. Surgeons can also consider leaving the eye somewhat soft relative to the patient's usual ocular tension at the end of the case, with the idea that it will allow proper collapse of the capsular bag around the lens, Dr. Baartman said. "Lastly," he added, "I think all patients getting premium lens implants, including torics, should be made aware of the potential for re- sidual astigmatism and the possibili- ty of a fine tune in the future, which could include a laser or IOL rotation. When you have these discussions with patients before surgery and you do encounter the scenario after surgery, it's less of a surprise to the patient and makes it feel like less of a complication to both parties." Dr. Safran said using a cohesive viscoelastic in the injector may slightly reduce the risk of rotation postoperatively because it is less likely to coat the haptics and remain in place compared to a dispersive viscoelastic. He also recommended polishing lens epithelial cells from the capsular bag, thinking it makes the "capsular bag a little tackier" for the IOL to stay in position. "Some surgeons think that the increased fibrosis and capsule contraction caused by retained LECs prevents rotation, but these LEC-induced capsular bag changes do not occur for weeks, until long after the lens is likely rotate." Postoperative management Careful postoperative refraction is critical in determining the possible need for a toric adjustment, Dr. Baartman said. He prefers to wait until the patient's refraction is stable before going in to reposition the lens, though if the rotation is signifi- cant he might go in earlier. "Generally, I like to be sure of the refractive stability and the patient's lens position, that it's not going to continue to move before going in for a second surgery. The caveat here is waiting too long puts the patient through a longer delayed optimal position and might make the procedure difficult if the bag seals down," he said. Dr. Baartman said he uses astigmatismfix.com, a program that helps identify the optimal toric lens position of a given toric IOL and the postoperative refraction. "You get a magnitude of change required in the exact position compared to its current position to reduce the amount of astigmatism," he explained. If, after plugging numbers in, he finds residual astigmatism even after toric rotation would still be visu- ally significant, Dr. Baartman said he considers IOL exchange or laser ablation. "Sometimes when there is a pristine cornea and no irregular astigmatism noted on topography and we know that we are at a good position with the toric lens rota- tionally but our spherical power is off, we're more likely to go in and change the lens power. Generally, if we're within a diopter of spherical equivalent, we'll do a laser, which is less risk for the patient than going in and exchanging the lens," Dr. Baartman said. When Dr. Baartman is going in to rotate a toric lens, he said he is more likely to rely on the axis proposed by astigmatismfix.com vs. intraoperative aberrometry, which he used when placing the lens pri- marily. In terms of knowing when to correct a rotated toric, that depends on your threshold, Dr. Safran said. "If you're using a low power toric and it's rotated 5 or 10 degrees, that might only be a 10th of a diop- ter," he said. "If it's a higher power toric, that could become a signifi- cant amount." Dr. Safran said he refracts his patients at postop day 1 and again at 1 week postop. If the toric lens is not where he wants it to be and it's causing enough residual astigma- tism to be considered significant, he will take a 30-gauge needle, go in through the limbus, and rotate it appropriately just at the slit lamp. "Most doctors don't do slit lamp rotation like I do; they're not comfortable with it. So I tell those doctors if you have a rotated toric in a high myope, wait about 5–6 " I think all patients getting premium lens implants, including torics, should be made aware of the potential for residual astigmatism and possibility of a fine tune in the future, which could include a laser or IOL rotation. " —Brandon Baartman, MD

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