EyeWorld Asia-Pacific June 2013 Issue

June 2013 15 EWAP FEAturE If rotating a toric IOL, Dr. Black recommends loosening any and all adhesions of the capsule both to itself and the IOL using the viscoelastic of your choice. This often requires the use of a 27-gauge needle to very carefully initiate the separation of the capsular edge from the anterior surface of the IOL, Dr. Black said. He then suggests rotating the IOL a minimum of 180 degrees to make sure the haptics do not remain within a capsular sheath that might lead to postop rotation back to the unintended axis. To assist with alignment before surgery, Deepinder K. Dhaliwal, MD , associate professor of ophthalmology, and director of cornea and refractive surgery service, University of Pittsburgh School of Medicine, Pittsburgh, Pa., USA, will take the patient to the slit lamp and mark 12, 3, 6, and 9 o’clock using the slit beam and a marking pen. “I line up and mark the toric IOL axis based on my preoperative marks,” said Dr. Dhaliwal, noting that she does not have access to intraoperative aberrometry. She’ll also anesthetize and place betadine in the conjunctival fornices before marking to make sure the marks do not get washed out. “I have been very happy with the Lenstar for determining the magnitude and axis of astigmatism preoperatively,” Dr. Dhaliwal said. Accommodating IOLs Not hitting emmetropia is a “necessary evil” when using accommodating lenses, Dr. Berdahl said. “The lens is intended to flex in the eye. The flexibility changes the lens position, so it results in more variable outcomes after surgery,” he said. Although making postop corrections in this patient group is easy, the downside is that such enhancements take place fairly frequently, Dr. Berdahl said—in up to about 30% of his patients. A wait time of three months is reasonable for the lens to settle in the eye before deciding on enhancements, said the surgeons. Drs. Berdahl and Black prefer to do a YAG capsulotomy as necessary before enhancements as the YAG might change the refractive outcome. However, Dr. Black cautioned against doing a YAG if there’s any concern that the IOL may need to be explanted. Dr. Dhaliwal has at times found stability issues with accommodating lenses. For this reason, she believes the use of a capsular tension ring is crucial if the surgeon detects any intraop stability problems such as pronounced asymmetric posterior vault. The CTR will fully expand the capsular bag and allow the haptics to vault more symmetrically. Also, the CTR can prevent excessive capsular bag contraction particularly in older patients with weaker zonules. “I’ve had patients with a myopic shift at one month because this lens is inherently more unstable and the haptics will flex as the capsular bag contracts,” she said. One pearl in accommodating patients is making sure the haptics stay in the equator. “If they’re not in the capsular sulcus, you’ll end up with abnormal lens vault, which changes its position,” Dr. Berdahl said. Multifocal IOLs Multifocal IOLs tend to be less forgiving than other IOL types, surgeons said—so it’s especially important to correct astigmatism postop or even intraop if possible. Discussing the pros and cons of multifocals in advance of surgery could help head off postop problems that actually are connected to patient expectations. “I tell patients it’s not an exact science and that they have to be realistic,” Dr. Dhaliwal said. “I tell them that wearing thin glasses for some activities is an acceptable outcome.” Optimizing the ocular surface preop in these patients—or really, in any patients having cataract surgery—can help head off postop complications, Dr. Dhaliwal said. If there are problems after surgery, determine if the patient is unhappy with visual acuity (a power mismatch) or visual quality (such as contrast sensitivity issues), Dr. Dhaliwal recommended. “If it’s a problem with visual quality despite optimal refraction, an enhancement may not help,” she said. If the patient is struggling with nighttime glare and halos, Dr. Dhaliwal suggested driving glasses with any residual refractive error correction (even 0.50 D) or Alphagan (brimonidine, Allergan, Irvine, Calif., USA) drops at night to minimize pupillary dilation. Sometimes leaving a small light on in the car (such as from the glove compartment) can also help. “I try to stay conservative and avoid refractive surgery in patients who may have potential side effects such as increased dry eye postoperatively,” she said. A contact lens trial prior to enhancement can help determine if the patient’s symptoms decrease, Dr. Black said. If the patient needs postop corrections, the surgeons interviewed prefer PRK, particularly in older patients who may have more dry eye. However, if the patient requires an enhancement along the lines of 2 to 3 D or higher, Dr. Kim recommended considering the option of an IOL exchange or piggyback IOL. That said, “iLASIK [Abbott Medical Optics, Santa Ana, Calif., USA] offers a more rapid return of vision as well as less discomfort and is particularly preferred by patients with healthy corneas,” Dr. Black said. Because patients with previous refractive surgery require further monitoring for refractive surprises after premium IOL implantation, Dr. Kim is cautious about even considering premium IOLs in this patient group. “If it’s a high myope, you’ve already altered the normal profile of the cornea and induced aberrations. By implanting a multifocal IOL in these patients during cataract surgery, you run the high risk of further decreasing contrast sensitivity and exacerbating the higher-order aberrations,” he said. Ironically, these are often the same patients who are interested in presbyopia- correcting IOLs in the first place, so he may consider an accommodating IOL as an option in these cases, Dr. Kim said. EWAP Editors’ note: Drs. Berdahl has financial interests with Alcon (Fort Worth, Texas, USA/Hünenberg, Switzerland). Dr. Kim has financial interests with Alcon and Bausch+Lomb (Rochester, NY, USA). The other physicians have no financial interests related to their comments. Contact information Berdahl : 605-328-3937, johnberdahl@gmail.com Black : 812-284-0660, drbradblack@aol.com Dhaliwal : 412-647-2257, dhaliwaldk@upmc.edu Kim : 919-681-3568, terry.kim@duke.edu