EyeWorld India June 2017 Issue

44 EWAP cornea June 2017 Prepping the ocular surface for cataract surgery 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- correcting IOLs, which require the most accurate measurements for optimal refractive outcomes. These measurements can be thrown off by even a little dry eye. One study found average keratometry (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 variability in average K readings was associated with “statistically significant resultant differences in IOL power calculation,” Epitropoulos et al. wrote. 1 “Those who are refractively- minded recognize how important managing the ocular surface [prior to cataract surgery] is, particularly those who embraced advanced technologies early on and saw how important it was with presbyopia- 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 surgery that flags dry eye. If the questionnaire 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 keratometry mires for irregularity, and she’ll look for consistency among devices, like her optical biometer and topography readings. Irregularity or discontinuity on these fronts lead her to treat these patients for dry eye. Jeremy Kieval, MD , Lexington Eye Associates, Lexington, Massachusetts, said his cataract patient 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 Questionnaire, 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, Utah, 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. Depending on the etiology of the condition (senile ectropion, blepharitis, or aqueous deficiency, for example), he may test tear osmolarity or conduct LipiView (TearScience, Morrisville, 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 procedures 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 intense 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 cataract surgery can be challenging, Dr. Zavodni said. “Objectively, I will look for stability over time in topography images and biometry K values,” he said. “Ideally, I like to have at least a couple of weeks between data points, separating different measurements. Subjectively, I will look for the resolution of, or at least a plateau in the improvement of, epithelial dryness on the slit lamp exam.” Dr. Yeu also said she would look 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.