Eyeworld Supplements

John Berdahl, MD 6 Toric lens success depends on stability Toric IOLs are an ideal option for astigmatic cataract patients with .75 D of corneal astigmatism or greater. They address a known problem, one that is intuitive and logical to pa- tients. Just as I would not prescribe spectacles to patients without cor- recting astigmatism, it would make no sense to me not to offer a toric lens to my cataract patients. Toric lenses are more predictable than limbal relaxing incisions (LRIs) or astigmatic keratotomy (AK) in patients with more than 0.75 D of astigmatism. Incisional techniques have a less predictable healing re- sponse, and (if using a manual LRI technique) surgeons need to con- sider the variability in incision depth, arc, and angulation. The AcrySof* IQ toric IOL (Alcon, Fort Worth, Texas) features the aspheric technology and refrac- tive clarity of the AcrySof platform. Its excellent rotational stability makes treating corneal astigmatism in cataract patients very simple. Rotational stability, lens placement There cannot be enough emphasis on how crucial rotational stability is in a toric lens. The AcrySof lens material has a unique "tackiness" and has been shown to have greater fibronectin binding than other IOL materials, which promotes adhesion to the capsule (Figure 1). 1 This bond be- tween the anterior and posterior capsule helps to stabilize the lens in place and contributes to the rota- tional stability of the lens. 2 Delivering the lens in the capsu- lar bag is equally important. We want a lens that's flexible enough to be easily positioned to align on the axis. At the same time, we want a lens that is stable enough that the contraction forces of the capsular bag won't vault or distort the lens. The AcrySof platform is a nice balance between these two features. The single-piece platform's combina- tion of material and Stableforce hap- tics keep the AcrySof IQ toric lens stable and centered in the capsular bag, while the flexible haptic design allows for optimal placement in the bag, regardless of size. EW San Francisco 2013 Monday, April 22, 2013 6 Toric IOLs: Are they all the same? by John Berdahl, MD " The AcrySof lens material has a unique 'tackiness' and has been shown to have greater fibronectin binding than other IOL materials … This bond between the anterior and posterior capsule helps to stabilize the lens in place and contributes to the rotational stability of the lens. " Please refer to page 8 for important safety information about the Alcon products described in this supplement. Unfolding of the haptics An aspect of the AcrySof platform I particularly appreciate is the speed at which the haptics open in the bag. Surgeons have the appropriate time (about 10-20 seconds) to ma- nipulate the lens into its rough posi- tion before it is fully unfolded; those of us using intraoperative aberrome- try to refine outcomes enjoy that the lens unfolds relatively quickly. One pearl: Ensure the haptics are entirely unfolded when the case is finished, and completely remove the viscoelastic from behind the IOL. Then just "tap" the center of the lens posteriorly, so there is con- tact between the posterior capsule and the lens. If a surgeon realizes in the OR the lens has not been prop- erly aligned, my advice is to put a little viscoelastic under the lens, and rotate (always clockwise as the hap- tics move more freely in that direc- tion) the lens to the proper position. Clinical pearl: Finding the ideal axis Finding the ideal axis is the most important and sometimes the most challenging aspect of toric IOL im- plantation. Although this does not occur often, sometimes the lens is exactly where we intended to place it—but that location is not the ideal axis. Differentiating between the intended and ideal axis is necessary for these lenses. If there is residual astigmatism postoperatively, there are two op- tions: perform laser vision correction or return the patient to the OR and rotate the lens. David Hardten, MD, and I developed an online tool that is hosted by ASCRS that can help surgeons, www.ascrs.org/toric- results-analyzer. Surgeons input the manifest refraction, what toric lens is being used and its axis, and the site will calculate where the lens should be rotated to and estimate the new refraction. The key issues for surgeons to consider are whether the spherical equivalent is accept- able and whether the residual astig- matism is acceptable. I personally find that anything under 0.50 D of residual astigmatism is usually not noticeable to patients. A quality lens platform In my hands, the AcrySof IQ toric lens tackles some of the most chal- lenging issues of toric lenses through its material and design, and pro- duces great alignment, adhesion to the bag, and most importantly, ex- cellent rotational stability. As we continue to advance into more so- phisticated toric lenses and multifo- cal torics, I believe this lens platform will evolve seamlessly with us. *AcrySof is a trademark of Novartis. References 1. Linnola RJ, Sund M, Ylonen R, et al. Adhesion of soluble fibronectin, laminin, collagen type IV to intraocular lens materials. J Cataract Refract Surg. 1999;25:1486-1491. 2. Linnola RJ. Sandwich theory: Bioactivity- based explanation for posterior capsule opaci- fication. J Cataract Refract Surg. 1997;23:1539-1542. Dr. Berdahl is in private practice, Vance Thompson Vision, Sioux Falls, S.D. He can be contacted at 605-328-3937. Figure 1 Source: Alcon Alcon Monday_SF2103 8pages-DL_Layout 1 4/21/13 7:54 PM Page 6

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