Eyeworld

50 | EYEWORLD | DECEMBER 2020 ATARACT C with longer PVDF haptics specifically for intras- cleral haptic fixation, but they are only available in Japan. If some capsule support remains, the surgeon may choose to iris fixate an existing three-piece lens. Dr. Chee said she does not opt for iris fixation unless there is some capsular support. She added that one potential downside is that iris fixated IOLs may dislocate years later in patients who chronically rub their eyes. Iris fixation may also incur a cat's eye pupil, she said. are simple techniques to master, she added, and the position of the sclerotomies are determined by the remaining zonules (if any). When fixing both ends, Dr. Chee said they should be posi- tioned diametrically opposite from one another. The Yamane technique or a glued IOL tech- nique are other options for refixating the IOL. Dr. Chee said she has learned never to reuse the existing IOL for intrascleral haptic fixation. Instead, she exchanges them for either a CT LUCIA 202 or 602 with PVDF haptics or the AR40E SENSAR lens with PMMA haptics. She added that both Hoya and Santen make IOLs continued from page 49 Cutting IOLs One important thing to know when planning to cut IOLs is that it is hard to cut a PMMA lens, Dr. Rocha said. However, for hydrophilic or hydrophobic lenses, you can cut them in the anterior chamber and remove them through the small incision. To remove PMMA lenses, Dr. Safran said he makes a 6-mm scleral tunnel on the steep axis with a self-sealing incision. You can put pars plana trocars in and an infusion line to keep the eye firm, he said. If it's PMMA, it should come out in one piece, Dr. Safran said. Though he said that he sometimes will cut the haptic and go after those separately. Dr. Safran said that "all of the foldable lenses," including hydrophilic acrylic, hydrophobic acrylic, or silicone, should cut readily. Dr. Chee also shared some tips for cutting IOLs. If possible, she said to mobilize the IOL into the anterior chamber to cut in order to avoid capsular injury. She also said to ensure that the entire capsular bag is bowed posteriorly with OVD to prevent both anterior and posterior capsule injury, as OVD may be lost during the cutting process. "This is especially important when cutting the optic if the entire IOL cannot be mobilized into the anterior chamber," she said. "Make sure that the tip of the scissors does not cut the capsulorhexis rim." Another technique for reducing the risk of posterior capsule injury is to insert the new IOL into the capsular bag, under the old IOL. Dr. Chee said the new IOL acts as a scaffold to protect the posterior capsule while the old IOL is being cut in the anterior chamber. She said to use intraocular scissors that are intended for the purpose and ensure they are sharp. Grasp the IOL firmly with intraocular forceps when cutting. Or you could provide a counterforce opposing the cutting force to prevent the IOL from slipping. Dr. Chee said to ensure that no sliver of the IOL is left in the eye during the cutting process. Dr. Chee said that the IOL can be cut into two or three pieces, depending on the incision size de- sired. "A useful technique that avoids the need to rotate one half of the IOL during explantation to avoid the haptic snagging the intraocular structures is to use the 'Pacman' method," she said. "This involves cutting the IOL three-fourths across and rotating the cut section followed by the rest of the IOL out through the incision." The way an IOL behaves when cut also depends on the IOL material. Dr. Chee said the AcrySof IOLs (Alcon) tend to be thinner, softer, and easier to cut than the thicker, more rigid TECNIS IOL (Johnson & Johnson Vision). She added that hydrophilic IOLs are softer, thinner, and easier to cut across and can be removed through a smaller incision than hydrophobic IOLs. However, silicone IOLs are slip- pery and thick and are the most difficult to explant. Contact Chee: chee.soon.phaik@ singhealth.com.sg Rocha: karolinnemaia@gmail.com Safran: safran12@comcast.net continued on page 52

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