Eyeworld

toric toolbox: Building skills and strategies to surgically manage astigmatism To minimize postoperative IOL rotation, Dr. Fram offered the following tips: •Use meticulous measurement and marking techniques •Use intraoperative aberrometry or a digital marker (Figure 1) •Remove all OVD from behind the IOL •Gently push the optic posteriorly •Perform a balanced salt solution stress test at the end of surgery 4 | SUPPLEMENT TO EYEWORLD | NOVEMBER 2019 Nicole Fram, MD Planning for success: Pearls for axial marking Accurate preoperative marking is crucial for successful outcomes A stigmatism significantly influences cataract sur- gery, affecting patients' eligibility for intraocular lenses (IOLs), vision quality, and postoperative satisfaction. "Depending on the IOL technology, more than 0.50 D of residual cylinder may leave a patient symptomatic," Nicole Fram, MD, said. methods may be used to mark alignment. At bedside or the slit lamp, patients should be in an upright position for manual marking to avoid artifacts from cyclorotation, Dr. Fram explained. She thinks the most precise way to manually mark is at the slit lamp and a level handheld marker can be equally effective. "The key is to make sure the patient is anesthetized, a fine-tip marker is used, and the patient looks in the distance to avoid con- vergence," she said. "Robert Osher, MD, has long advocated using iris fin- gerprinting and scleral vessel imaging to help guide toric IOL placement," she said. "When available, this is an ex- cellent way to provide precise measurements." Comparing manual mark- ing with a pendulum-attached marker vs. a digital marking system, Elhofi et al. found less postoperative deviation from the targeted induced astigma- tism. 3 They also found less postoperative IOL misalign- ment when a digital marking system was used compared with manual marking. Dr. Fram explained: • Digital marking systems, such as CALLISTO (Zeiss) and VERION (Alcon), begin with a preoperative reference image that is transmitted to the oculars for alignment and astigmatic planning. • The LENSAR IntelliAxis uses a preoperative image from a CASSINI or Penta- cam (OCULUS) to refer- ence the steep axis, which is transmitted to the femtosec- ond laser. Tabs are created in the capsulotomy to allow intraoperative marking of the steep axis. • Intraoperative aberrometry measures the aphakic refrac- tion and gives a steep axis recommendation based on wavefront aberrometry to allow toric IOL alignment and power suggestion. "All of these technologies show promising advance- ments. However, I recom- mend a manual reference mark preoperatively because digital technology may Postoperative astigmatism may be caused by an incorrect lens power, which may result from incorrect measurements or calculations, posterior cor- neal astigmatism, or surgically induced astigmatism, she ex- plained. 1 It also may occur if the IOL rotates after surgery or is not aligned correctly. "For every 1 degree of error, you lose 3.3% of astig- matic correction," Dr. Fram said. 2 Surprisingly, the ASCRS Clinical Survey shows that some respondents believe 10 degrees of IOL rotation is acceptable. "This highlights the critical importance of accurate preoperative marking when managing astigmatism," Dr. Fram said. Axis alignment Several manual and digital Figure 1. Intraoperative image of intraoperative aberrometry with reticle overlay of steep axis. continued on page 5

• Blank Page
• Blank Page (1)