EyeWorld India December 2019 Issue

EWAP DECEMBER 2019 29 SECONDARY FEATURE cornea,” he said. Dr. Barrett stressed that when selecting a toric lens the traditional toric formulas “are not valid” in eyes with previous refractive surgery. “If you’ve had previous refractive surgery and you’re selecting a toric lens, a traditional toric calculator is not appropriate,” he said. “The assumptions are no longer valid after refractive surgery. You need > Ã«iVwV ÌÀV V>VÕ>ÌÀ] >` that is the True K Toric calculator. /i /ÀÕi 6iÀÃ ÌÌ«\ÉÉ calc.apacrs.org/Barrett_True_K_ Universal_2105/) also takes into account the posterior cornea. Towards precise outcomes The evolution of cataract surgery, said Rosa Braga- Mele, MD, FRCSC, has taken practitioners and patients alike from focusing on safety, Ì ivwViVÞ] >` w>Þ Ì outcomes—moving from just cataract surgery to cataract refractive surgery so that outcomes need to be more predictable. Dr. Braga-Mele took on the question of whether intraoperative aberrometry is “worth the effort.” Has intraoperative aberrometry—which Dr. Braga- Mele described as real-time streaming refraction meeting all the clinical requirements for managing sphere, cylinder, and alignment of the lens—really been proved to be any better? She said that papers have shown that intraoperative aberrometry improves astigmatic outcomes, toric IOL selection, lens power calculation, and post-myopic LASIK. Dr. Braga-Mele said that she “only uses” the IOLMaster 700 and the Barrett Universal formula in post-refractive surgery eyes, but also incorporates the ORA intraoperative aberrometry in the OR. She considers intraoperative aberrometry “worth the effort” in post-refractive patients, high cylinder eyes, and where effective lens positioning could be more unpredictable such as in high myopes or post-pars plana vitrectomy eyes; it also accounts for both the anterior and posterior corneal surface, and can help improve toric IOL alignment. However, she admitted, current intraoperative aberrometry is still reliant on preoperative biometry and not solely on intraoperative measurements, can increase chair time, and is more iÝ«iÃÛi° Even with the most advanced instruments and techniques and in the hands of “the most iÝ«iÀiVi` >` iÌVÕÕÃ surgeons,” IOL selection is an imperfect science and refractive surprises can—and do—occur due to myriad factors. One solution is to allow refractive adjustments after cataract surgery is completed and the IOL has been implanted in the eye—and the Light Adjustable Lens (LAL) allows just that. Edward Manche, MD, discussing whether the LAL is a “niche or necessity,” said the LAL is producing “truly phenomenal outcomes.” In the U.S. FDA study leading to the LAL’s approval for use in the United States, 91.8% of eyes achieved refractive outcomes within 0.5 D of target MRSE. In comparison, he said, 90.9% of LASIK eyes achieve refractive outcomes within 0.5 D of target MRSE. In addition, he said, the LAL provides superior quality of vision in all measures including best-corrected visual acuity, ÛÃ À>Ì}] `ÀÛ} `vwVÕÌÞ] dim light conditions, glare, halos, and contrast sensitivity. The LAL also has the potential to provide superior reduction in astigmatism. In terms of technique, the LAL eliminates the need for corneal marking and issues with toric alignment and rotation, and allows surgeons to treat corneal and surgically induced astigmatism postop. However, it does necessitate patients be committed to wearing sunglasses for 1-2 weeks before the surgeon optimizes the lens (if necessary) and it locks into place. Nevertheless, he said, the LAL “has created a paradigm shift in how we’re going to do cataract surgery in the future.” Other panelists were not as convinced, as Dr. Barrett noted the lens needs to be locked in before refractive stability can be truly assessed. Managing refractive surprises /i wÀÃÌ Ã«i>iÀ Ài«ÀiÃiÌ} Europe, Thomas Kohnen, MD, PhD, FEBO, offered advice on how to handle misaligned IOLs. If it’s a toric lens, recalculate the >ÝÃ] Ìi V>VÕ>Ìi Ìi `ÀiVÌ of rotation, and then reposition the toric lens by either rotation À ÀiwÝ>Ì]i Ã>`° “Repositioning should be performed 1 week after IOL implantation at the earliest, but preferable 10 days, or 1-2 weeks, postop,” he said. At this time, he said, the initial capsular wound healing process will better keep the lens in position. He further recommended using a bimanual technique for IOL rotation, and said that intraoperative aberrometry can be helpful. 7i ÀivÀ>VÌÛi ÃÕÀ«ÀÃiÃ occur, Oliver Findl, MD, MBA, said solutions include IOL iÝV>}i] >`` " Ã] À " `wV>ÌÃ° iÃ ÃvÌ depends on the IOL haptic design, with 1-piece lenses completing their shift in about 1 Üii >` Î«iVi " Ã wÃ} in 2-3 months. º/i LiÃÌ Ìi Ì iÝV>}i an IOL is earlier rather than >ÌiÀ]»i Ã>`] >Ã wLÀÃÃ VVÕÀÃ at 2-3 months postop. In eyes with shallow anterior chambers, Dr. Findl recommends cutting the lens out to replace it. Dr. Findl also described another option currently under investigation for adjusting refractive outcomes after cataract surgery that does not require a special lens ÃÕV>Ã Ìi Ƃ \ ÀivÀ>VÌÛi `iÝ Ã>«} v ÃÌ>`>À` hydrophobic acrylic IOLs using a femtosecond laser.