Eyeworld

EW CORNEA 48 June 2018 by Maxine Lipner EyeWorld Senior Contributing Writer Inflammation's role in dry eye T he vicious cycle of inflam- mation is at the root of dry eye disease for some patients. A study published in Ophthalmology 1 took a closer look at this connection with the hope of teasing out the impact of inflammation on dry eye disease, said Francis Mah, MD, director of corneal and external disease and co-director of refractive surgery, Scripps Clinic, La Jolla, California. The two medications currently FDA approved for dry eye—Restasis (cyclosporine, Allergan, Dublin, Ireland) and Xiidra (lifitegrast, Shire, Lexington, Massachusetts)—impact parts of the inflammatory cascade, Dr. Mah said. How these drugs actu- ally influence inflammation, how- ever, is not well understood. "For a long time, we didn't know, for example, how cyclosporine worked or how it affected dry eyes," he said. Even with lifitegrast, where there's a known mode of action, there is still a desire to determine what the role of inflammation is and how it could be possible to affect this. Eyeing the inflammatory rabbit hole 3. Hagen KB, et al. Comparison of a single- dose vectored thermal pulsation procedure with a 3-month course of daily oral dox- ycycline for moderate-to-severe meibo- mian gland dysfunction. Clin Ophthalmol. 2018;12:161–68. Editors' note: Dr. Kading and Dr. O'Dell have financial interests with Johnson & Johnson Vision. Contact information Kading: drdave@specialtyeye.com O'Dell: lodell@dryeyecenterofpa.com "There is always a lot of skepti- cism and resistance to new technol- ogy from the optometry and oph- thalmology communities, so any study comparing old standards is important," she said. "Doxycycline was one of the standards of care that we had to treat meibomian gland dysfunction, so to see if a treatment in the office that's only 12 minutes long and all natural can be as effec- tive as 3 months of an antibiotic is powerful." Dr. O'Dell thinks the study also validates why she got away from prescribing doxycycline, an antibi- otic with anti-inflammatory prop- erties, in favor of LipiFlow for MGD patients. The adverse side effects of the drug, such as sun sensitivity, urinary tract infections, and GI dis- tress, for example, were her primary reasons. LipiFlow being an in-office procedure also takes away any pa- tient compliance issues. With both LipiFlow and doxy- cycline improving meibomian gland function without a statistically significant difference between the two (as shown by the number of glands yielding clear meibum after treatment), Dr. O'Dell said there is at least something to be said for the statistically significant difference in SPEED scores in favor of LipiFlow. "Even though we want to make the eye function better and opti- mally, patients want to feel better. I think the significance is that patients are feeling better, which is encouraging because that helps them stay adherent to whatever the modality of treatment is," Dr. O'Dell said. EW References 1. Blackie CA, et al. A single vectored thermal pulsation treatment for meibomian gland dys- function increases mean comfortable contact lens wearing time by approximately 4 hours per day. Clin Ophthalmol. 2018;12:169–183. 2. Lemp MA, et al. Distribution of aqueous-de- ficient and evaporative dry eye in a clinic- based patient cohort: a retrospective study. Cornea. 2012;31:472–8. Studies continued from page 46 Research highlight Exploring the literature Michelle Rhee, MD, assistant professor of ophthalmology, Icahn School of Medicine at Mount Sinai, New York, said that she and Dr. Mah performed a literature review on the topic covering the period from 1973 through March 2017. "We have known for decades that there are reports in the literature about inflammation's core role in dry eye disease," she said. Technological advances have offered a new under- standing. "We're able to definitively show that inflammation is both the cause and effect of dry eye and it's not a postulation anymore," she said. Dr. Mah said that investiga- tors focused on the inflammatory cascade and the drugs that were associated with this, such as ste- roids, lifitegrast, cyclosporine, and nonsteroidal anti-inflammatory medication. In breaking the inflammatory cycle, some things have become clear. For example, some power- ful agents are less specific than others. "Steroids work at a global level where it's like using an atom bomb, whereas with lifitegrast it's like using a rifle," Dr. Mah said. "Yet both can be effective in treating dry eye." Likewise, cyclosporine is more specific than steroids. "It's a more defined pathway than lifitegrast, but we still don't know all the steps," he said. "We found that there's inflam- mation in ocular surface disease, and that the mode of action of many of these modalities of treat- ment impacts the inflammatory cas- cade," Dr. Mah said, acknowledging that more questions have emerged. Although the volume of pub- lished literature on the topic has exploded over the last decade, inves- tigators have just as many questions concerning markers, how different inflammatory cascades are related, and how the different mechanisms of action of available medications Eyes such as this with punctate epithelial keratopathy are among those affected by the inflammatory cycle. For dry eye patients, investigators considered how medications impacted the inflammatory cascade. Source: Francis Mah, MD

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