Eyeworld

4 4 The impact of refractive error on outcomes and patient satisfaction Avoiding refractive surprises with presbyopia-correcting IOLs by Elizabeth Yeu, MD Clinical Survey, 57% of surgeons think ocular surface dysfunction occurs in less than 20% of their cataract patients. When ocular surface problems go unnoted and untreated, we are much more likely to see refractive surprises because of poor image capture or incorrect IOL selection. In addition, if suboptimal, fluctuating, or blurred vision results from dry eye that has not been treated, patients will be dissatisfied with their outcomes. We also need to emphasize the importance of continuing dry eye treatments after surgery to main- tain optimal visual outcomes. Refractive packages Surgeons should have a plan for correcting refractive error when a surprise occurs. In my practice, refractive packages that include preoperative assessments and matism would be to use intraop- erative aberrometry; it is not nec- essary to initially invest heavily in expensive capital equipment to be an effective refractive cataract surgeon. However, these devices can be very valuable in further mitigating refractive surprises. Excluding dry eye Patient selection for refractive cataract surgery or refractive lens exchange is a key component in achieving successful outcomes. Surgeons need to carefully ex- amine the ocular surface of any patient who is considering these procedures. More than 60% of our cataract surgery patients have at least mild to moderate dry eye disease that is clinically seen on the slit lamp even if they are not necessarily symptomatic. 1 Howev- er, according to the 2015 ASCRS A closer look at corneal astigmatism Advanced preoperative diagnostics are also essential. In my experi- ence, the i-Optics Cassini device with the Total Corneal Astigma- tism (TCA) software, along with corneal topography, is particularly helpful in avoiding postoperative refractive surprises. In a retrospective review of my own toric IOL results (n=50 eyes), the TCA software has in- creased the accuracy of my results, demonstrating a 0.50-D residual refractive astigmatism in 94% of eyes, compared with 84% using the Barrett Toric Calculator and 76% with the Baylor nomogram. Posterior corneal astigmatism plays an important role in refrac- tive astigmatism management, and our data suggest that it is actually aligned with the rule posteriorly in ~75% of eyes, which may be less than we thought pre- viously. Moreover, oblique astig- matism was seen in more than 22% of corneal astigmatism cases that I was treating, and these eyes behave very differently posterior- ly than eyes that have vertically or horizontally oriented anterior corneal astigmatism. About half of these eyes have TCA that is less than that seen anteriorly, whereas the other half of oblique eyes have TCA that is greater than the ante- rior corneal astigmatism. Another way to better understand the total corneal astig- To optimize results, surgeons need to address astigmatism and focus on quality care every step of the way P atients have high hopes when they invest in pseudophakic presby- opia-correcting surgery, but their expectations may promptly deflate if refractive error remains untreated. In my clinical experience, in patients with multifocal IOLs, which are exquisitely sensitive, visual acuity declines by 1 line per 0.25 D of astigmatism. Patients will be dissatisfied if surgeons do not nail the spherical equivalent. The good news is that sur- geons can achieve their targeted outcomes in most patients, but it requires a strong commitment to refractive cataract surgery. Before beginning to implant presbyopia-correcting IOLs, sur- geons should consider whether they have the necessary surgical skills and plans in place to be successful (see box). In striving for improved refractive outcomes, for example, we need to know our surgically induced astigmatism (SIA) and the expected outcome of limbal relaxing incisions. Surgeons can calculate their personal SIA using an online calculator (sia-cal- culator.com). Elizabeth Yeu, MD Presbyopia-correcting IOL surgery requirements • Select appropriate candidates • Master surgical skills and IOL power calculation • Optimize ocular surface • Manage astigmatism • Use good marking technique • Know your SIA • Plan for refractive enhancement if necessary " Surgeons may choose to bundle options to make it simpler for patients to understand and to deliver a seamless spectrum of care. " –Elizabeth Yeu, MD

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