Toric intraocular lenses

Supplement to EyeWorld August 2015 Driving adoption and outcomes with toric IOLs: Pre-, intra-, and postoperative pearls for success 2014 ASCRS Clinical Survey: Trends in toric IOL implementation Click to read and claim CME credit by John Vukich, MD John Vukich, MD Survey reveals practices in employing toric IOLs and managing astigmatism Toric intraocular lenses (IOLs) are of major interest among today s cataract surgeons. To gauge current practices pertaining to this technology, ASCRS included questions regarding astigmatism management and toric IOLs in the annual ASCRS Clinical Survey. This analysis, which focuses on the most compelling and controversial issues facing ASCRS members, identifies areas where there may be educational opportunities. Designed to determine members clinical opinions and practice patterns, the 2014 ASCRS Clinical Survey produced 268 data points from 137 questions, with responses from more than 1,500 unique respondents. 1 The 2014 survey revealed important information regarding ways surgeons are implementing toric IOLs and managing astigmatism in their patients. Factors that guide management When respondents were asked about the primary preop measurement driving their astigmatism axis decisions when implanting a toric IOL, overall, 11% use manual or autokeratometry when making their choices, whereas 45% use topography. When they were asked how they align the preoperative axis assessed with their diagnostic tools with their intraoperative axis where they are placing the toric IOL during surgery, 37% used anatomic landmarks with no marking or used ink marking without instruments. We think this technique may be prone to increased error. However, I think clinicians are changing direction in this area as we increasingly understand how to optimize outcomes with toric IOLs. Less than half of ASCRS members responding to the survey reported that they calculate continued on page 2 Accreditation Statement This activity has been planned and implemented in accordance with the Essential Areas and policies of the Accreditation Council for Continuing Medical Education through the joint providership of the American Society of Cataract & Refractive Surgery (ASCRS) and EyeWorld. ASCRS is accredited by the ACCME to provide continuing medical education for physicians. Educational Objectives Ophthalmologists who participate in this activity will: Outline the importance of accurate preoperative measurements with advanced diagnostic tools, for axial length, keratometric data, and IOL power as well as the magnitude and pattern of astigmatism in the achievement of positive outcomes in the management of astigmatism in cataract patients with toric IOLs and the best methods for collecting such data; discuss the optimal therapeutic target for residual cylinder that should be part of best practices in the management of astigmatism with toric IOLs; Describe the critical steps necessary for accurately aligning the preoperative and surgical axis of astigmatism through use of modern marking and alignment technologies, as well as intraoperative means for locking of the IOL after implantation; Recognize the significance of all sources of astigmatic error, and develop a toolkit to manage appropriately; and Identify the impact of incremental rotational misalignment from intended axis and its direct impact on visual quality and patient satisfaction. Assess current knowledge regarding the prevalence of rotation with toric IOLs and why it occurs Discuss the approaches to preventing and/ or resolving IOL rotational error Designation Statement The American Society of Cataract and Refractive Surgery designates this enduring materials activity for a maximum of 1.0 AMA PRA Category 1 Credits. Physicians should claim only credit commensurate with the extent of their participation in the activity. Claiming Credit To claim credit, participants must visit bit.ly/1non4uf to review content and download the post-activity test and credit claim. All participants must pass the post-activity test with a score of 75% or higher to earn credit. Alternatively, the post-test form included in this supplement may be faxed to the number indicated for credit to be awarded, and a certificate will be mailed within 2 weeks. When viewing online or downloading the material, standard Internet access is required. Adobe Acrobat Reader is needed to view the materials. CME credit is valid through February 29, 2016. CME credit will not be awarded after that date. Notice of Off-Label Use Presentations This activity may include presentations on drugs or devices or uses of drugs or devices that may not have been approved by the Food and Drug Administration (FDA) or have been approved by the FDA for specific uses only. ADA/Special Accommodations ASCRS and EyeWorld fully comply with the legal requirements of the Americans with Disabilities Act (ADA) and the rules and regulations thereof. Any participant in this educational program who requires special accommodations or services should contact Laura Johnson at ljohnson@ ascrs.org or 703-591-2220. Financial Interest Disclosures John Berdahl, MD, receives a retainer, ad hoc fees, or other consulting income from and is a member of the speakers bureau of: Alcon Laboratories Inc., Allergan Inc., Avedro Inc., Glaukos Corporation, and Omega Ophthalmics. He has received a retainer, ad hoc fees, or other consulting income from: Abbott Medical Optics Inc. and ClarVista. Dr. Berdahl has an investment interest in Avedro Inc. and Glaukos Corporation, and has received research funding from Alcon and Glaukos. Dr. Berdahl has received travel expense reimbursement from Alcon. David R. Hardten, MD, has an investment interest in ESI Inc. and OSD Inc. He has received a retainer, ad hoc fees, or other consulting income from Abbott Medical Optics Inc. and Allergan. Dr. Hardten has received research funding (full or partial) from Abbott Medical Optics Inc., Calhoun Vision Inc., and DREAM. He is a member of the speakers bureau of Allegan. Bonnie An Henderson, MD, has received a retainer, ad hoc fees, or other consulting income from Alcon Laboratories Inc. and Bausch + Lomb. She is a member of the speakers bureaus of Abbott Medical Optics Inc. and Genzyme. Douglas D. Koch, MD, has received a retainer, ad hoc fees, or other consulting income from Abbott Medical Optics Inc. He is a member of the speakers bureau of Alcon Laboratories Inc. Dr. Koch has received research funding (full or partial) from i-optics, Revision Optics Inc., TrueVision, and Ziemer Inc. John A. Vukich, MD, is a member of the speakers bureaus of: Abbott Medical Optics Inc., AcuFocus Inc., and STAAR Surgical. Staff members Laura Johnson and Erin Schallhorn have no ophthalmic-related financial interests. Supported by an unrestricted educational grant from Abbott Medical Optics, Alcon Laboratories, and Bausch + Lomb

2 Driving adoption and outcomes with toric IOLs: Pre-, intra-, and postoperative pearls for success continued from page 1 Nearly one-third of survey respondents stated that 10 degrees or more of rotational error is acceptable after toric IOL implantation. Overall, 25% of respondents ignore posterior corneal cylinder because they believe it is insignificant Ignore it because it is typically insignificant Estimate it based on published average values Measure for each patient and include it in my calculations 0.0% 10.0% 20.0% 30.0% 40.0% 50.0% 60.0% U.S. Non-U.S. Overall The 2014 ASCRS Clinical Survey asked, How do you manage posterior corneal cylinder? their surgically induced astigmatism based on their own recent surgical results. Clearly, we have come to understand that our surgical techniques affect outcomes and must be taken into consideration. The survey showed that 25% of respondents overall ignore posterior corneal cylinder because they believe it is insignificant. However, we continue to learn that this may be an important factor that we should take into account. Nearly one-third of survey respondents stated that 10 degrees or more of rotational error is acceptable after toric IOL implantation before visual quality and acuity are significantly affected. Although I think this view is shifting substantially, we will need to improve our efforts to hit our target to attain optimal visual outcomes. When respondents were asked about the procedure they use most often to manage astigmatism in patients with cataracts, only 54% reported that they implant a toric IOL in patients with 1.25 D of Toric IOL strategies for success Responding to some of the educational gaps identified by this survey, this supplement shares the astigmatism management strategies and toric IOL optimization techniques of some of our most noted experts. They will discuss the impact of rotational error, ways to improve treatment planning, techniques for intraoperative alignment, and how to manage postoperative error in toric IOL patients. Reference 1. 2014 ASCRS Clinical Survey. Global Trends in Ophthalmology. Fairfax, VA: American Society of Cataract & Refractive Surgery, 2014. Dr. Vukich is a partner at the Davis Duehr Dean Center for Refractive Surgery in Madison, Wis. He can be contacted at javukich@facstaff.wisc.edu. 45.0% 40.0% 35.0% 30.0% 25.0% 20.0% 15.0% 10.0% 5.0% 0.0% Less than 5 5 6 to 9 10 Greater Depends than 10 U.S. Non-U.S. Overall 30.2% of respondents believe 10 degrees or more is acceptable The 2014 ASCRS Clinical Survey asked, After implanting a toric IOL, how many degrees of postoperative rotational error is acceptable before visual quality and visual acuity are significantly affected? On axis incision 0.75 D 1.25 D 2 D 3 D 42.1% 12.0% 0.9% 0.5% Manual LRI or AK 13.2% 17.1% 3.5% 1.1% Femtosecond laser LRI or AK 7.9% 8.3% 1.6% 1.1% Toric IOL 5.9% 53.9% 89.7% 91.6% Postop laser vision correction 0.9% 1.6% 2.7% 3.6% Glasses or contact lenses 7.1% 5.3% 1.5% 1.8% No special correction needed 22.9% 1.9% 0.1% 0.2% Only 54% of respondents reported they would implant a toric IOL in a patient with 1.25 D of astigmatism The 2014 ASCRS Clinical Survey asked, What is your most common procedure to manage astigmatism in a cataract patient with the following levels of cylinder?

Supported by unrestricted educational grants from Abbott Medical Optics, Alcon Laboratories, and Bausch + Lomb 3 Impact of rotational error on toric IOL outcomes by John Berdahl, MD John Berdahl, MD Precise IOL alignment is essential for crisp, clear vision, but it is particularly critical with high-powered IOLs When correcting astigmatism during cataract surgery, it is easy to reach the 5-yard line. However, it takes considerable effort to target sources of potential error and consistently reach the end zone. Residual astigmatism There are 3 causes of residual astigmatism after intraocular lens (IOL) implantation: positioning the IOL incorrectly, choosing the incorrect IOL, or implanting the IOL in an eye with severe ocular surface disease, anterior basement membrane dystrophy, or irregular The IOL may be implanted in the wrong location or an incorrect IOL may be used if measurements or calculations were performed incorrectly or as a result of unexpected surgically induced astigmatism (SIA). Posterior corneal astigmatism also plays a role. Roughly 80% of the time this is against-the-rule, but at least 15% of the time it is with-the-rule Therefore, estimating posterior corneal astigmatism rather than measuring it can result in suboptimal outcomes. Furthermore, the IOL may rotate or it may have been positioned improperly. If the correct IOL is used but it is in the wrong position, I prefer to rotate the IOL. If the incorrect IOL was used, I may perform an IOL exchange or laser vision correction. Tools for correction To guide surgeons in correcting residual astigmatism, David Hardten, MD, and I created the Toric Results Analyzer (astigmatismfix.com). In a large database, we found that in 76% of cases the intended axis will not neutralize the most Moreover, the IOL rotated 70% of the time. Therefore, in 52% of cases both of these problems contribute to residual Figure 1 shows that at 0 degrees of misalignment, vision is crisp and clear with a T9 IOL. If this IOL is misaligned by 15 degrees, patients have much blurrier vision. If the IOL is misaligned by 1 degree, the patient loses approximately 3.3% of the effective toric power; if it is off by 10 degrees, the patient loses approximately 35% of the toric power (Figure 2). Although this may be less significant with low power lenses such as a T3 resulting in 0.36 D of astigmatism with high-powered toric IOLs it is a major problem. A T9 corrects 4.11 D at the corneal plane. Therefore, the patient will have almost 1.5 D of residual astigmatism with a 10-degree misalignment. One of our patients received a T9 IOL and had 3.5 D of astigmatism 1 week after surgery. When we plugged the information into the Toric Results Analyzer at astigmatismfix.com, it Figure 1. Misalignment of a T9 IOL dramatically affects vision. Misalignment % loss Figure 2. The effects of IOL misalignment on toric correction indicated that rotating the lens 28 degrees clockwise would reduce the astigmatism to less than 1.0 D. During surgery, I looked at the preoperative and intraoperative aberrometry measurements, which confirmed that she had approximately 3.0 D After we rotated the IOL 28 degrees, we repeated intraoperative aberrometry measurements and found that the measured residual astigmatism was less than 0.5 D. One day after we rotated the IOL, she was plano 20/20 and very pleased. Although surgeons may not achieve their target results every time when implanting toric IOLs, Absolute loss T3 (1.03 D) T9 (4.11 D) 0 degrees 0% 0 D 0 D 5 degrees 17.5% 0.18 D 0.71 D 10 degrees 35% 0.36 D 1.43 D 15 degrees 50% 0.51 D 2.05 D 30 degrees 100% 1.03 D 4.11 D tools such as excimer lasers and understanding whether to perform an IOL exchange or rotate the IOL can be very helpful. Conclusion Precise IOL alignment is especially critical when implanting high-powered toric IOLs, but it will be more important with toric multifocal IOLs, which are even more sensitive to residual Dr. Berdahl is in practice at Vance Thompson Vision in Sioux Falls, S.D. He can be contacted at john.berdahl@ vancethompsonvision.com.

4 Driving adoption and outcomes with toric IOLs: Pre-, intra-, and postoperative pearls for success Preoperative tools and diagnostics: Pathways to improved treatment planning with toric IOLs by David R. Hardten, MD David R. Hardten, MD Surgeons must manage astigmatism to achieve good uncorrected vision More than 70% of cataract patients have 0.5 D of astigmatism or more before surgery. 1 It is crucial to recognize this and successfully manage astigmatism to provide the uncorrected vision our patients seek. We have a number of tools at our disposal to help us reach this goal. These include corneal relaxing incisions and laser vision correction, but toric intraocular lenses (IOLs) are gaining popularity and offer an excellent means to correct very significant levels of Technologic necessities It is remarkable how many patients are referred to us after implantation of a toric IOL because they are unhappy with their astigmatic results. Irregular astigmatism is one of the main reasons for residual astigmatism after implantation of a toric IOL. Irregular astigmatism may result from previous RK or LASIK, anterior basement membrane dystrophy, dry eye, previous scars, and other conditions. Surgeons seeking good refractive outcomes in their patients with astigmatism must determine the true astigmatic power of the cornea before surgery and predict how it will change after surgery. They also must verify whether astigmatism is regular. Toric IOLs feature a flat axis and steep axis, but they cannot correct for asymmetric Topography is necessary to verify that the astigmatism is regular; K readings are not sufficient. Regular astigmatism also may change if the incision is made in a slightly different location than intended. Furthermore, the internal incision or incision length can dramatically affect the amount of induced Surgeons should consider their average astigmatic result or customize their results. Surgeons must also be able to position the IOL correctly intraoperatively and examine and verify it after surgery. IOL misplacement or postoperative IOL rotation can result in residual We need to accurately measure the primary curvature and verify that measurement. Tomography can be used to examine the anterior and posterior curvatures and understand the asphericity. This also can be accomplished empirically by nomograms of average asphericity and ratios of anterior and posterior corneal In addition, we can use a system that measures front and back, such as the Pentacam (Oculus, Arlington, Wash.) or the Galilei analyzer (Ziemer Ophthalmic Systems, Port, Switzerland), Figure 1. Barrett calculator available at www.ascrs.org/barrett-toric-calculator which can measure total corneal curvature by subtracting the back curvature of the front of the eye. An accurate calculator and reliable alignment method are essential. The Barrett toric IOL calculator on the ASCRS website (www.ascrs.org/barrett-toric-calculator), which can be used for any toric IOL, can help surgeons estimate asphericity based on population averages (Figure 1). This formula also takes into consideration posterior corneal curvature and the lens position. Conclusion A number of low-tech tools are available to guide toric IOL implantation. We need to verify that the patient s topography shows regular astigmatism and be very wary of considering toric IOLs in patients with irregular The irregularity creates an outcome that typically can t meet expectations of most patients when using toric IOLs, which only correct the regular component of the For optimal results, surgeons should use a high-quality calculator that incorporates asphericity. They also should consider measuring it directly with a tomography system. Almost everyone has some degree of astigmatism that must be addressed. Our patients have high expectations. We need to make every effort to reduce astigmatism to less than 0.5 D. Reference 1. Hoffmann PC, Hütz WW. Analysis of biometry and prevalence data for corneal astigmatism in 23,239 eyes. J Cataract Refract Surg. 2010;36(9):1479 1485. Dr. Hardten practices with Minnesota Eye Consultants in Minneapolis. He can be contacted at drhardten@mneye.com.

This CME supplement is supported by unrestricted educational grants from Alcon and Bausch + Lomb. Supported by unrestricted educational grants from Abbott Medical Optics, Alcon Laboratories, and Bausch + Lomb 5 Intraoperative toric IOL alignment: Technologies and techniques for optimal outcomes by Bonnie An Henderson, MD Bonnie An Henderson, MD Device manufacturers continue to strive for seamless integration of systems Most cataract surgeons rely on manual marking techniques when implanting toric intraocular lenses (IOLs), but technologic advances are streamlining this process by linking automated systems. Learn more about the array of available options to determine the best ways to improve accuracy and your surgical outcomes. Manual marking With manual marking techniques, it is critical to avoid the effects of cyclorotation. In a LASIK study, Swami et al. reported that the average torsional misalignment was approximately 4 degrees, but more than 8% rotated more than 10 degrees. 1 To avoid the effects of cyclorotation, surgeons must make preoperative reference marks on the cornea while the patient is upright. Subsequently, when the patient is supine, surgeons can use marking instruments that are held with one hand by dialing in the steep axis on a marker, then marking the cornea and aligning the preoperative reference marks to determine the incision location. Another approach is to use marking instruments with a bimanual approach and mark the steep axis with the other hand. Device manufacturers are linking systems with preoperative, intraoperative, and postoperative data collection to decrease human error and improve overall outcomes. High-tech systems Image-guided systems increasingly link devices seamlessly to reduce the risk of manual data entry errors, while eliminating the need for manual marking. Wirelessly or with a USB stick, these tools capture data in a clinical area and transfer it to the intraoperative area, potentially decreasing the risk of error. The Verion Reference Unit (Alcon, Fort Worth, Texas) measures keratometry, pupillometry, and other parameters in the surgeon s office and produces a high-resolution image of the eye (Figure 1). This information is imported into the planning continued on page 6 Figure 1. Preoperative measurements performed with Verion Image Guided System Figure 2. Zeiss Cataract Suite graphical overlays are displayed on the monitor as well as the eyepiece through the Integrated Data Injection System.

6 Driving adoption and outcomes with toric IOLs: Pre-, intra-, and postoperative pearls for success continued from page 5 Figure 3. The Cassini relies on LED point-to-point ray tracing of the cornea to perform corneal analysis and high-resolution images to direct surgery. Practice pearl: When using toric IOLs, it is important to take into consideration the effects of cyclorotation. Additionally, using marking instruments or a refractive reference unit is important to align the IOL properly. Figure 4. The Holos IntraOp provides continuous, real time feedback. software, and then these data, along with the plan, are transferred to the LenSx laser (Alcon) and surgical microscope with a USB stick. The Zeiss Cataract Suite uses the IOLMaster (Carl Zeiss Meditec, Jena, Germany) in the clinic to capture noncontact biometry numbers. Based on data obtained from the Zeiss Forum data management system, the Callisto Eye (Carl Zeiss Meditec) creates custom overlays and transfers this information to the OPMI Lumera microscope (Carl Zeiss Meditec) (Figure 2). The Cassini (i-optics, The Hague, the Netherlands) relies on LED point-to-point ray tracing of the cornea and also provides information about the posterior corneal curvature (Figure 3). The Holos IntraOp system (Clarity Medical Systems, Pleasanton, Calif.), which is under development, displays continuous, real time refractions throughout surgery (Figure 4). A built-in digital video recorder records the procedure. The ORA system (Alcon) shows real-time refractive data. It performs aphakic calculations that take into consideration the corneal incision and posterior corneal curvature. Pseudophakic calculations check the power and alignment of the toric IOL and assess the effects of limbal-relaxing incisions. If the IOL is misaligned during surgery, we can continue rotating the lens until we reach our target (Figure 5). Conclusion Many high-tech and low-tech tools are available to guide IOL alignment. Device manufacturers are linking systems with preoperative, intraoperative, and postoperative data collection to decrease human error and improve overall outcomes. Reference 1. Swami AU, Steinert RF, Osborne WE, White AA. Rotational malposition during laser in situ keratomileusis. Am J Ophthalmol. 2002;133(4):561 562. Dr. Henderson is clinical professor of ophthalmology at Tufts University School of Medicine, Boston, and a partner at Ophthalmic Consultants of Boston. She can be contacted at bahenderson@eyeboston. com. Figure 5. Screenshot of the ORA system, which shows whether additional IOL rotation is necessary

Supported by unrestricted educational grants from Abbott Medical Optics, Alcon Laboratories, and Bausch + Lomb 7 Pearls for achieving surgical success with toric IOLs Douglas D. Koch, MD To ensure patient satisfaction, surgeons must be prepared to refine postoperative outcomes if necessary Implantation of toric intraocular lenses (IOLs) is more than a procedure it is a comprehensive process, said Douglas D. Koch, MD. Surgeons must take critical steps before, during, and after surgery to ensure precise visual outcomes and patient satisfaction. Causes of error Regardless of surgeons experience, surgical outcomes occasionally fall short, Dr. Koch said. There are many causes. Preoperative measurements may be imperfect (Figure 1). Intraoperatively, misalignment can occur, Dr. Koch said. Marks may be blunt or imprecisely located, and there may be parallax as the surgeon examines the lens. Furthermore, surgically induced astigmatism (SIA) may vary because of the wound construction and location, as well as the patient s biologic features (Figure 2). The effects of relaxing incisions also may differ. Postoperatively, the IOL can rotate, he said. In addition, a spherical error may occur. Additional treatments After surgery, patients with monofocal IOLs may require additional treatment if residual astigmatism is 0.75 D or greater, depending on their visual needs, Dr. Koch explained. 1 With a multifocal IOL we have to be much tighter, reducing astigmatism to less than 0.5 D, he said. Hayashi et al. reported that patients had 20/20 vision at distance if astigmatism was 0 after implantation of an AcrySof ReSTOR IOL with a +3.0 D add (Alcon, Fort Worth, Texas), but if they had 0.5 D of astigmatism, their vision decreased to 20/30. 2 When making postoperative adjustments, surgeons need to consider the alignment of the IOL, whether they have under- or overcorrected the astigmatism, the magnitude of the error, and the IOL power accuracy, Dr. Koch said. If the IOL power is incorrect, he recommended an excimer laser ablation or IOL exchange, depending on the magnitude of the error. He suggested an IOL exchange for larger residual errors, especially on the hyperopic side. If the spherical power is correct, the IOL is aligned, and astigmatism is within 1.25 D, he performs a peripheral corneal relaxing incision if it was not performed previously. He takes this approach regardless of whether astigmatism is under- or overcorrected. If there are existing relaxing incisions, you can either reopen them, enlarge them, or even consider making another one, he said. If astigmatism is 1.5 D or greater, he recommends considering excimer laser ablation or IOL exchange. If the IOL is misaligned and astigmatism is 1.0 to 1.25 D, he again prefers relaxing incisions. If it exceeds 1.25 D, the Toric Results Analyzer developed by John Berdahl, MD, and David Hardten, MD, is a helpful tool (astigmatismfix.com). Figure 1. Dual Scheimpflug Placido map of a patient with a large amount of anterior and posterior corneal astigmatism; ignoring or misestimating the latter can result in suboptimal uncorrected acuity. Figure 2. Dr. Koch s SIA in a series of eyes Conclusion Astigmatism correction is a process with our patients, Dr. Koch said. There are critical steps before, during, and after surgery. It s mandatory to be prepared to adjust your patients postoperatively in order to provide them with optimal outcomes. Fortunately, we have excellent options available to us, thanks to things like astigmatismfix.com and techniques as simple as relaxing incisions. References 1. Villegas EL, Alcón E, Artal P. Minimum amount of astigmatism that should be corrected. J Cataract Refract Surg. 2014; 40:13 19. 2. Hayashi K, Manabe S, Yoshida M, Hayashi H. Effect of astigmatism on visual acuity in eyes with a diffractive multifocal intraocular lens. J Cataract Refract Surg. 2010; 36(8):1323 1329. Dr. Koch is a professor and the Allen, Mosbacher, and Law chair in ophthalmology, Cullen Eye Institute, Baylor College of Medicine, Houston. He can be contacted at dkoch@bcm.edu.

8 Driving adoption and outcomes with toric IOLs: Pre-, intra-, and postoperative pearls for success To take this test online and claim credit, go to bit.ly/1non4uf or complete the test below and fax, mail, or email it in. CME questions (circle the correct answer) 1. According to Dr. Berdahl, if a toric IOL is misaligned by 10 degrees, the patient loses approximately what percentage of the effective toric power? a. 15.3% b. 35% c. 25% d. 10.5% 2. Residual astigmatism after toric IOL implantation may result from irregular astigmatism, which can be caused by: a. Dry eye b. Previous LASIK c. Anterior basement membrane dystrophy d. All of the above 3. According to Dr. Koch, patients may require additional treatment after implantation of monofocal IOLs if: a. Residual astigmatism is 1.0 D or greater b. Residual astigmatism is 0.50 D or greater c. Residual astigmatism is 0.75 D or greater d. Residual astigmatism is 0.25 D or greater 4. According to Dr. Henderson, image-guided total refractive suites: a. Eliminate the need for manual marking b. Reduce the risk of human error c. Transfer data directly to the surgical area d. All of the above 5. Based on results in a large database, Dr. Berdahl reported that IOLs rotated: a. In 70% of cases b. In 60% of cases c. In 10% of cases d. In 30% of cases To claim credit, please fax the test and fully completed form by February 29, 2016 to 703-547-8842, email to GPearson@ascrs.org, or mail to: EyeWorld, 4000 Legato Road, Suite 700, Fairfax, VA 22033, Attn: August 2015 CME Supplement ASCRS Member ID (optional): First/Last Name/Degree: Practice: Address: City, State, Zip, Country: Phone: Email: Please print email address legibly, as CME certificate will be emailed to the address provided. Copyright 2015 ASCRS Ophthalmic Corporation. All rights reserved. The views expressed here do not necessarily reflect those of the editor, editorial board, or the publisher, and in no way imply endorsement by EyeWorld or ASCRS.