FEATURE EWAP DECEMBER 2023 13 from the limbus (e.g., 2.5–3 mm instead of 2 mm), especially in cases where the iris is highly mobile and floppy. Although controversial, one can consider shortening the haptics,” Dr. Nakatsuka wrote. Dr. Kim also said that if the needles are pierced through the sclera too anteriorly, it could cause the haptics to rub the overlying uveal tissue resulting in UGH or CME. IOL decentration or tilt: This complication can occur due to asymmetrical scleral tunnels at different lengths or angles, Dr. Pettey and Dr. Nakatsuka said. To ensure proper centration, Dr. Pettey and Dr. Nakatsuka advised “meticulous pre-surgical marking with calipers and a Mendez ring to ensure targets are precisely 180 degrees apart, and mark the center of the cornea. Close observation of the scleral indentation during the docking procedure can alert the surgeon to an asymmetry between each side to ensure symmetric tunnels. Ensure that the globe is firm during the scleral needle insertion and avoid hypotony throughout the procedure. We recommend maximal pupil dilation to facilitate visualization during the docking step.” (See Figure 2). Dr. Nakatsuka experienced a few cases of rotation of the haptic at the optic-haptic junction with the CT LUCIA lens (Carl Zeiss Meditec), although it appears to be isolated to a particular batch of these lenses. Dr. Kim also mentioned the recent issues observed with the CT LUCIA lenses, which he described as a “rotisserie rotation.” “Surgeons have observed that these haptics are not completely fused within the optic, causing them to rotate,” he said. “There is a technique called laser - lock, 2 which uses the endolaser to essentially melt the haptic to the optic to address this.” Lens/optic capture: Dr. Nakatsuka has experienced a few cases where the lens optic moves in front of the iris pupil. Floppy iris appears to be a risk factor for this complication (see Figure 3). In addition to similar pearls for avoiding UGH, Dr. Pettey and Dr. Nakatsuka said that treatment options include miotics, supine positioning with miotics, laser iridoplasty, or surgical pupilloplasty to prevent the lens from coming forward. They said some surgeons recommend multiple peripheral iridotomies but noted the efficacy is still unclear. Dr. Yamane recommends a 7.0-mm optic X-70 IOL (Santen) to avoid pupillary capture of the optic, but Dr. Kim said optic capture can still occur if the IOL is too close to the iris plane. “Rather than placing the needles 2 mm posterior to the limbus, I prefer to place them further back at 2.5 mm and target –0.50 D for a plano refractive result,” he said. “With this modification, along with always placing a temporal surgical peripheral iridectomy to avoid reverse pupillary block, I have not experienced any cases of optic capture.” Flagpole sign: Dr. Kim said that there needs to be adequate scleral support for the haptics with this technique. “If there is inadequate scleral support for the haptics because the needles are not tunneled through the sclera, the haptics may point up in a more vertical orientation, which I’ve coined the ‘flagpole sign,’” he said. “If there is a flagpole sign, this means the optic is sagging posteriorly within the vitreous space, which would induce optic tilt and astigmatism. A self-check to know the IOL is placed correctly is when you observe the haptics are lying flat to the sclera when the needles are pulled out.” Hypotony: Dr. Pettey and Dr. Nakatsuka said the Yamane technique requires the use of thin gauge needles (30 gauge) and long, oblique tunnels, but they are still prone to leaking. “On the extreme end of the spectrum,” they wrote, “Marfan patients or others with very long axial length have thin sclera and are considerably more prone to leaking. Additionally, we often do these cases combined with retina providers, whose ports may not consistently seal.” Recently, Dr. Nakatsuka had a patient with a completely collapsed eye after the procedure, which he thought was likely due to a small leak from a retina port in combination with aqueous suppression that can occur with ciliary body trauma. “Hypotony is a more frequently encountered Figure 2. Lens tilt or decentration can occur due to a variety of reasons during intrascleral haptic fixation, especially of the scleral tunnels.
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