More than 1.5 million men and twice that many women over the age of 50 are estimated to suffer from dry eye (Schaumberg et al, 2009; Schaumberg et al, 2003). With updated information and including younger patients, the specter of this disorder is likely an order of magnitude greater and is inescapable in eyecare practice. From impaired quality of life to reduced contact lens wearing time, the problem and its numbers and effects are confounding. Many attempts at palliative to curative measures have proved only marginally successful. But the recent U.S. Food and Drug Administration (FDA) approval of a new medication for dry eye has brought us a novel approach for this common condition.

A Case in Point

A 53-year-old female presented with complaints consistent with dry eye disease. Her visual acuity was somewhat variable, but she was capable of 20/20 in each eye with persistent blinking. She was a former contact lens wearer who discontinued due to insufficient wearing time and inconsistent vision, especially at the end of the day. Figure 1 shows her anterior segment at presentation. Note the coalesced staining pattern.

The patient was prescribed Xiidra (lifitegrast ophthalmic solution, 5%, Shire) for instillation q12h, according to the package insert. Figure 2 shows her anterior segment two weeks later. There was a remarkable resolution of the epithelial disruption as well as a reported relief of symptoms.

Mechanism of Action

Xiidra is the first FDA-approved topical medication to treat the symptoms and signs of dry eye disease (www.accessdata.fda.gov ). It is the first integrin lymphocyte function-associated antigen-1 (LFA-1) that interacts with the intercellular adhesion molecule-1 (ICAM-1). This mechanism appears to interrupt the cascade involved in immune responses and inflammation, especially those prominent in ocular surface inflammation (Abidi et al, 2016; Pflugfelder et al, 2017). Safety and efficacy have been demonstrated over three clinical trials that led to the FDA approval in July 2016 (Holland et al, 2016; Holland et al, 2017). Data from these trials are compelling for not only efficacy, but the rapid improvement in clinical symptoms, some as soon as two weeks, as demonstrated in this case.

Side Effects

The most common adverse reactions (incidence 5% to 25%) observed during the Phase II and III clinical trials of Xiidra were instillation site irritation, dysgeusia, and decreased visual acuity (www.accessdata.fda.gov ). My experience among patients using Xiidra is that the perverted taste sensation is variable, yet the most frequently reported side effect. Some notice nothing, while others report a range of specific descriptions from “sour” to “yucky” to “an uncomfortable drying sensation.” In only one case in my early experience has the dysgeusia been the reason for discontinuation. Patients can try mouthwash, brushing their teeth, or drinking something such as orange juice to overcome any taste sensation. CLS

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