Eyeworld

EW CORNEA 80 March 2017 by Liz Hillman EyeWorld Staff Writer What to look for, how to treat it, and how to counsel these patients I n recent years, managing the ocular surface has become a more popular topic, both in general and in conjunction with other procedures. With regard to cataract surgery, the focus on a healthy ocular surface is in part driven by presbyopia-correct- ing IOLs, which require the most accurate measurements for optimal refractive outcomes. These measure- ments can be thrown off by even a little dry eye. One study found average ker- atometry (K) readings and anterior corneal astigmatism were more variable in a group of patients with hyperosmolar eyes compared to a group with normal tear osmolarity. This statistically significant variabili- ty in average K readings was asso- ciated with "statistically significant resultant differences in IOL power calculation," Epitropoulos et al. wrote. 1 "Those who are refractive- ly-minded recognize how important managing the ocular surface [prior to cataract surgery] is, particular- ly those who embraced advanced technologies early on and saw how important it was with presby- opia-correcting lenses, particularly multifocals," said Elizabeth Yeu, MD, assistant professor, Department of Ophthalmology, Eastern Virginia Medical School, Norfolk, Virginia. "Even the littlest amount of dry eye could lead to significant patient dissatisfaction." Identifying the dry eye patient Dr. Yeu said all her patients take a symptom questionnaire prior to sur- gery that flags dry eye. If the ques- tionnaire indicates they're positive, then tear osmolarity testing is done along with other diagnostics, but Dr. Yeu stressed that one can't rely on a questionnaire or what a patient is telling you alone. "One of the biggest things we realized is, especially for our older patient population, they're often not having the classic symptoms. You might miss it because they're not complaining about it," she said. As such, Dr. Yeu will check ker- atometry mires for irregularity, and she'll look for consistency among devices, like her optical biometer and topography readings. Irregular- ity or discontinuity on these fronts lead her to treat these patients for dry eye. Jeremy Kieval, MD, Lexington Eye Associates, Lexington, Massa- chusetts, said his cataract patients also receive a questionnaire to alert him to any dry eye symptoms. Their standard exam includes evaluation of lid anatomy, blink rates, tear meniscus, tear film breakup time, and vital-dye staining. Other dry eye diagnostics, such as the Ocular Surface Disease Index Question- naire, Schirmer's, meibography, and Inflammadry (RPS, Sarasota, Florida) are reserved for other dry eye point- of-care testing. Zachary Zavodni, MD, The Eye Institute of Utah, Salt Lake City, said he relies on observations at the slit lamp, placido-disc topography quality, and consistency in optical biometry K values to screen cataract patients for significant dry eye. De- pending on the etiology of the con- dition (senile ectropion, blepharitis, or aqueous deficiency, for example), he may test tear osmolarity or con- duct LipiView (TearScience, Morris- ville, North Carolina) imaging. Managing the condition Once Dr. Kieval finds evidence of dry eye, he said he'll start the patient on aggressive lubrication, warm compresses, and omega-3 fatty acid supplements as a first line of treatment. Dr. Yeu offers office-based pro- cedures like LipiFlow (TearScience) to patients who don't seem to respond to these typical treatments. Patients with exposure issues—those who have a poor blink or whose lids don't close all the way—are good candidates for self-retaining, cryopreserved amniotic membrane therapy, like ProKera (Bio-Tissue, Doral, Florida). "Prokera is great at providing whole corneal coverage for 3 to 5 days, and it can at least temporarily provide a significant improvement so you can capture the images that you want to," Dr. Yeu said. Drs. Kieval and Zavodni also said they offer LipiFlow at their offices. Dr. Zavodni added that in- tense pulsed light therapy is also an option for these patients who need more aggressive treatment. After treatment, determining when the ocular surface is "ready" for accurate measurements and cat- aract surgery can be challenging, Dr. Zavodni said. "Objectively, I will look for sta- bility over time in topography imag- es and biometry K values," he said. "Ideally, I like to have at least a cou- ple of weeks between data points, separating different measurements. Subjectively, I will look for the reso- lution of, or at least a plateau in the improvement of, epithelial dryness on the slit lamp exam." Dr. Yeu also said she's looking for healthy mires, the absence of concerning hot spots or flat spots on axial maps, and continuity among devices. "If all that looks good coupled with their examination, then I know we're a go," Dr. Yeu said. Counseling patients on expectations "Patients coming in for cataract surgery evaluations really wanted it done yesterday," Dr. Yeu said. This is why counseling a patient who needs to resolve ocular surface issues prior to surgery is particularly important because of the possibility for delay. In these patients, Dr. Yeu said she typically schedules surgery for the first eye 6 weeks out and the sec- ond 8 weeks out, telling them they'll return for repeat testing at 3 to 4 weeks to see if surgery can proceed as scheduled. "In the meantime, I tell them, 'I need to have a commitment from you that we're going to use these medications or drops in order to get the best imaging possible so I can help you achieve the quality of vision you're looking for,'" she said. If at the 4-week checkup the pa- tient still hasn't responded to treat- ment for adequate measurements, Dr. Yeu said they can push back sur- gery for the first eye to the 8-week mark, which was already on the schedule for the second eye. This, Dr. Yeu said, allows her patients to feel like they are moving forward with a date still on the calendar. Dr. Kieval said his typical sur- gery schedule runs 2 to 3 months out, a timeframe that usually allows Prepping the ocular surface for cataract surgery T he health of the ocular surface is an important variable in the refractive result of cataract surgery. If proper attention is not paid to the uniformity of the corneal refractive surface and tear film prior to surgery, patient disappointment and frustration may follow postop. In this month's column, YES clinical committee members Jeremy Kieval, MD, Elizabeth Yeu, MD, and Zachary Zavod- ni, MD, offer their insights on optimizing cataract surgical outcomes for patients with coexisting dry eye. In my clinical practice I have found that an ever-increasing contributor to dry eye is the ubiquity of screen-time in modern life, whether it be televisions, computer monitors, smartphones, or tablets. Cataract surgery patients are not spared from this culprit: a 2014 Pew Research Center report states that 74% of seniors between the ages of 65–69 use the internet, and 84% in this age group own a cellphone. 1 More screen- time is linked to fewer blinks, which refresh the ocular surface. Whereas an average resting blink rate is 14.5 blinks per minute, this frequency drops by nearly 50% when reading to 7.9 blinks per minute. 2 In addition to the expert recommendations provided in the column, encourage patients to take breaks to look away during visually intensive activities and to be conscious of their blink- ing. Any intervention to improve a dry ocular surface will pay dividends in preparation, execution, and post-operative outcome of cataract surgery. 1. Pew Research Center. "Older Adults and Technology Use. April 2014. Available at: www.pewinternet.org/2014/04/03/old- er-adults-and-technology-use/ 2. Doughty MJ. Consideration of three types of spontaneous eyeblink activity in normal humans: During reading and video display terminal use, in primary gaze, and while in conversation. Optom Vis Sci. 2001;(78)10:712–725. Charles H. Weber, MD YES Connect co-editor YES Connect continued on page 84

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