Eyeworld Supplements

4 EW Chicago 2012 Sunday, April 22, 2012 4 T oric IOLs offer an efficient and consistent method of correcting pre-existing corneal astigmatism in cataract patients. A 2010 study published in the Journal of Cataract & Refractive Surgery 1 found that toric IOL implantation was more predictable and effective than limbal relaxing incisions (LRIs) in correcting refractive astigmatism, resulting in greater spectacle inde- pendence. The AcrySof IQ Toric IOL (Alcon, Fort Worth, Texas) offers an excellent range of visual correction that gives us the capability to correct 0.75 D to 4.0 D of pre-existing corneal astigmatism. In addition to these advantages, toric IOLs obviate the need for the additional incisions required with LRIs. In light of these advantages and the excellent visual outcomes achieved, I think the AcrySof IQ Toric IOL is quickly emerging as the new standard of care for patients with cataracts and pre-existing corneal astigmatism. Corneal astigmatism: When to treat? When treating with a monofocal IOL, residual astigmatism of even 0.75 D should be considered visually significant and all of these patients considered as potential candidates for the AcrySof IQ Toric IOL. Physi- cians know that 0.5 D of astigma- tism creates a considerable amount of visual aberration for a patient and can cause vision to drop to the 20/30 to 20/40 ranges. In monofocal lens patients who are predicted to have residual astigmatism of 0.8 D or 0.9 D, I will consider implanting a lower power of the AcrySof IQ Toric IOL, the T3, which will leave them with 0.1 or 0.2 in the opposite direction to achieve the best possible visual outcome. Regarding the higher levels of astigmatism, we are now able to address a greater range of refractive error. However, I always recommend surgeons perform topography in these pa- tients to rule out ectasia or any type of progressive irregular astigmatism. Incisional LRIs versus toric IOLs The reason that torics are preferred by many surgeons in patients with 0.75 D of pre-existing corneal astig- matism or greater is because the toric IOL is more predictable and consistent than LRIs 2 ; there is no risk of regression later on. Larger LRIs may also induce significant pe- ripheral aberration, which certainly runs counter to our goal of minimiz- ing, not creating, aberrations. Surgical pearls If surgeons have not yet implanted a toric lens, the AcrySof IQ Toric IOL is an excellent way to get started. Surgical technique doesn't vary much from monofocal IOL implan- tation. One small adjustment you must make is marking the 3, 6, and 9 o'clock axes pre-op before the patient lays down to avoid misplacement of the IOL due to ocular cyclorotation in the supine position. Once you have mastered marking the desired axis intraopera- tively, it's just a matter of rotating the IOL clockwise after insertion to those marks. Post-op issues A question that often arises is, "What if the toric lens is off by 5 degrees?" In my opinion, when you check the patient on that first post- op day and the vision is good and the patient is happy, where the lens ended up is not nearly as important as you might think. The intended axis is merely an approximation based on pre-op K readings. It cannot provide full knowledge of where the lens should be placed as we know there are other factors that may influence post-op refractive cylinder. If the patient is happy, there's no need to bring him/her back into the OR. Leave the lens alone. Conversely, if a patient is not happy with his/her vision post-op or comes in with 20/40 vision, which rarely happens, and thinks he/she is happy, the surgeon must dilate that patient to verify the axis position. If the lens is misaligned, even by as little as 10 or 15 degrees, I take the patient back to the OR and rotate the lens to the intended axis deter- mined pre-op. Remember, the patient will not complain of tilted images, etc.—just blurry vision as one loses 3% of the cylinder power for each degree of misalignment. You can make these patients happier. Patient education Educating the patient about astigma- tism and what a toric lens actually does is equally important. Although many patients know that they have astigmatism, their understanding of it may be very limited. We like to use visuals when explaining astig- matism to a patient, likening the shape of their eye to a football rather than a basketball, or a teaspoon rather than a soup spoon. We explain that this irregular shape interferes with their vision and that the AcrySof IQ Toric IOL will figura- tively correct the shape of their eye. We then explain to patients that without correcting this problem, their vision without glasses will not be as clear, i.e., it will cause halos around lights and/or less distinct vision and reduced contrast. Provid- ing detailed patient education allows patients to make an informed deci- sion. It is not uncommon for pa- tients to say, "I don't mind wearing glasses," whereupon I will explain that it's not simply about spectacle freedom. It is about quality of vision. People understand that it's optically superior to correct astigma- tism inside their eye as opposed to wearing glasses. Also, I will often ask patients, especially the high astig- mats, how often their glasses had to be remade in the past when their astigmatism wasn't properly corrected. Then I tell them that with a toric lens, those days are over. References 1. Mingo-Botin, D. et al., Comparison of toric intraocular lenses and peripheral corneal relaxing incisions to treat astigmatism during cataract surgery, J Cataract Refract Surg 2010; 36:1700-1708. 2. Data on file, Novartis AG. Dr. Black is founder of Dr. Brad Black's Eye Associates in Jeffersonville, Ind. Contact information Black: drbradblack@aol.com Please refer to page 12 for important safety information about the Alcon surgical products described in this supplement. " The reason that torics are preferred by many surgeons in patients with 0.75 D of pre-existing corneal astigmatism or greater is because the toric IOL is more predictable and consistent than LRIs " Brad Black, M.D. Should toric IOLs become the standard of care? by Brad Black, M.D. Alcon Sunday supplement_Chicago2012-12pages_Layout 1 4/20/12 4:50 PM Page 4

• Cover