Today, over 38 million Americans experience dry eye symptoms.1 Of these, only about 17 million have a formal diagnosis of dry eye, and among them, only approximately 1.2 million actually have a prescription.2 Ultimately, this means two things: many patients with dry eye don't know because they haven’t been given a formal diagnosis, and even if a patient has received this diagnosis, they likely aren’t receiving adequate symptom relief because chances are they're not on a prescription medication.
There are numerous factors to assess when considering dry eye, many of which change over time. However, two of the most common elements are evaporative disease components, which affect around 86% of dry eye patients, and inflammation.3 Although patients may use over-the-counter options, such as artificial tears, warm compresses, and omega-3 supplementation4, these approaches often don’t offer sufficient symptomatic relief. As practitioners, we can help by providing our patients with prescription medication treatments that can substantially improve signs and symptoms of dry eye.
Miebo (perfluorohexyloctane ophthalmic solution) First, Fast, and Tolerable
Miebo is the first and only drop that specifically targets excessive tear evaporation. It’s indicated for the treatment of the signs and symptoms of dry eye disease; although this may seem obvious, there are currently only 8 approved Rx DED eye drops and 2 have tear production as their label indication. Another thing the package insert contains is the potential adverse reactions, and if you look at Miebo’s, there’s a significant item that was not listed for the first time ever in a DED eye drop: instillation site reactions. For me, this is one of the best parts about Miebo. It's water-free, making it pH-free, osmolarity-free, preservative-free, and steroid-free. Miebo is also the first and only Rx DED drop that contains a single ingredient—perfluorohexyloctane.
But how does it actually work? Perfluorohexyloctane, which is biologically inert, has both aerophilic and lipophilic segments. While the exact mechanism of action is not known, it orients itself based upon these attractions to form a monolayer at the air-tear interface of the tear film, preventing tear evaporation. The exact mechanism of action of MIEBO in DED is not known. In practice, as demonstrated in the FDA-approved clinical trials, patients with dry eye disease and Meibomian gland dysfunction treated with Miebo demonstrated statistically significant improvements in total corneal staining at day 15, with this continuing to day 57. However, most patients don't care about corneal staining; what they want is symptomatic relief, and fast. Miebo also demonstrated statistically significant improvement in patient symptoms at day 15, and even more by day 57. In these two studies, which included over 600 patients treated with Miebo, the discontinuation rate due to adverse events was very low—comparable to prescribing the medication a thousand times and having only two patients choose to discontinue treatment.5-6 In clinical trials, the most common adverse reactions reported in 5-25% of patients were instillation site irritation, dysgeusia and reduced visual acuity. Other adverse reactions reported in 1% to 5% of the patients were blurred vision, conjunctival hyperemia, eye irritation, headache, increased lacrimation, eye discharge, eye discomfort, eye pruritus and sinusitis.
As practitioners, we have a lot of confidence that Miebo is effective, not only in the long term but also quickly. This confidence is reinforced because the comparison was made against a hypotonic saline solution, rather than a control vehicle (as a single ingredient drop, Miebo has no vehicle for comparison). We know that hypotonic saline lowers tear film osmolarity and provides lubrication to improve dry eye symptoms. Personally, I have had great success prescribing Miebo to patients who experience fluctuating vision and symptoms like burning, sandiness, or grittiness, which Miebo alleviated rapidly.
Xiidra (lifitegrast ophthalmic solution): A Unique Immunomodulator
Xiidra targets the inflammatory component of dry eye disease and is also indicated for treating the signs and symptoms of the disease. There are many other topical immunomodulators in the market. However, they all contain cyclosporine, a calcineurin inhibitor that helps reduce inflammation by preventing the activation of T-cells and thereby limiting the production of proinflammatory cytokines such as interleukin-2.7 Conversely, Xiidra contains lifitegrast - lifitegrast binds to the integrin LFA-1, a cell surface protein found on leukocytes and blocks the interaction of LFA-1 with its cognate ligand intercellular adhesion molecule-1 (ICAM-1). ICAM-1 may be overexpressed in corneal and conjunctival tissues in DED. LFA-1/ICAM-1 interaction can contribute to the formation of an immunological synapse resulting in T-cell activation and migration to target tissues. In vitro studies demonstrated that lifitegrast may inhibit T-cell adhesion to ICAM-1 in a human T-cell line and may inhibit secretion of inflammatory cytokines in human peripheral blood mononuclear cells. The exact mechanism of action of lifitegrast in DED is not known.
Xiidra received FDA approval following five clinical trials involving over 2,400 participants. These included one phase 2 study, three phase 3 studies, and a long-term safety study lasting 360 days.7,9 Focusing on the Phase 2 and Phase 3 studies, two out of four trials demonstrated a statistically significant reduction in symptoms, with half of the participants reporting improvement by two weeks. At six and twelve weeks, there were improvements in patient symptoms in all four trials.7 Additionally, three of the four studies indicated improvements in corneal staining and Xiidra is well tolerated with the exception of adverse events such as instillation-site irritation, dysgeusia, and decreased visual acuity. For these reasons, I advise patients that Xiidra can begin to work in as little as two weeks, but they should allow at least six weeks before evaluating its effectiveness. Doing so makes them statistically likely to experience improvements in their symptoms and continue using the medication.
Xiidra has outstanding coverage of approximately 90% in the US. This widespread acceptance allows patients to access Xiidra easily, regardless of the doctor who prescribes it. Miebo's coverage has also steadily improved over the past few years, and my patients have not encountered issues obtaining it through commercial insurance at this time. Additionally, BlinkRx provides patients with a faster way to receive Xiidra by offering support for prior authorization and helping to ensure affordable prices.
The dry eye market today is quite complex, with many different eye drops continually emerging that offer new ways to address our patients' signs and symptoms. I encourage you to move beyond linear thinking and the traditional trial-and-error approach to prescribing. Instead, focus on identifying the exact cause of dry eye disease so you can precisely tailor your treatment to each patient's specific signs and symptoms.
