For those who suffer from dry eyes, you understand the struggle of trying to manage the symptoms of gritty, sandy, stinging, burning, excessively watery, dry eyes. While many individuals can manage their dry eye symptoms with artificial tears and warm compresses, there are many others who continue to suffer.
Fortunately, research in this field is ever ongoing. Today there are several prescription strength dry eye drops—you may have even seen commercials for them on TV!
Dry eye is a chronic disease, meaning it will never completely go away as there is not yet a “cure”.
Dry eye results from either a quality or quantity problem—the eyes can either produce poor quality tears that evaporate too quickly, produce too little of an amount of tears, or a combination of both.
Our tears are composed of three layers—lipid, aqueous, and mucin.
The lipid layer is made from the glands that run vertically in the eyelids—called meibomian glands.
The aqueous layer is produced by the lacrimal gland (located at the outer edges of the eyebrows) and accessory lacrimal glands.
The mucin layer is made from specialized cells located in the corneal conjunctiva—called goblet cells.
We need strong components of all 3 layers—if one layer is lacking it causes instability across the entire tear layer, thus creating dry eye disease.
In some situations, dry eye disease is secondary to meibomian gland disfunction—MGD for short. In MGD, the glands within the eyelids die off (meibomian gland atrophy) leading to a significant decrease in lipid layer production.
Often times in these situations, the oil produced in the meibomian glands becomes thick, almost like a toothpaste consistency, and never even reaches the eye. This means the tear layer is missing the lipid component, increasing the layer’s evaporation rate.
Warm compresses—preferably via Bruder Mask—work towards liquifying the oils within the Meibomian glands, returning them to a “Crisco”-like consistency to better contribute to the tear layer.
In other situations, the lacrimal glands do not produce enough aqueous layer—leading to an overall decrease in the amount of tears produced.
When the eyes do not have enough tears, or the tear quality is poor, the corneal nerves within the eye detect the feeling of dryness as pain. The nerves then send a signal to the brain to produce more tears—hence why many individuals with dry eye actually complain of excessive watery/tearing eyes.
The nerves detecting pain also signal to the immune system that something is wrong. In response to this, the immune system upregulates inflammatory responses which further dry out the system.
The tears produced are of poor quality and the cycle progresses—Meibomian glands are destroyed during the attempt to work better and the tears are produced less and less, despite the signal to upregulate production.
Initial treatment for dry eye includes over-the-counter artificial tears such as Refresh, Systane, FreshKote, and Soothe tears, as well as warm compresses. However, this is often not enough. There are currently 3 major prescription dry eye drops—Restasis, Xiidra, and Cequa.
Restasis is an eye drop that got its FDA approval in 1983. It is prescribed to be taken every 12 hours, or twice a day.
Restasis is composed of 0.05% Cyclosporine. Cyclosporine is a drug used to decrease inflammation within the body. More specifically, Restasis is a Calcineurin Inhibitor immunosuppressant.
In addition to decreasing inflammation, Restasis also works toward encouraging the body to produce more natural tears. The combination of the two mechanisms of action lead to significant improvement in dry eye symptoms for the majority of patients.
Like any medication, Restasis can have sides effects, with the most common being a burning sensation of the eyes post-instillation. Other less common side effects include irritation, redness, and blurred vision.
Xiidra is an eye drop that got its FDA approval in 2016. It is also prescribed to be taken every 12 hour, or twice a day.
Xiidra is composed of 5% lifitegrast. Lifitegrast is also drug used to decrease inflammation within the body, but works via a different mechanism than cyclosporine. Specifically, lifitegrast is a lymphocyte function-associated antigen 1 antagonist.
In other words, Xiidra does essentially the same thing as Restasis—decrease inflammation while upregulating production of natural tears—but through a different biological pathway.
The most common side effects of Xiidra insillation are an unusual tase, irritation, and blurred vision. Other side effects include burning post-installation, headaches, and redness of the eyes.
Cequa is an eye drop that received its FDA approval in 2018. Like Restasis and Xiidra, Cequa is prescribed to be taken every 12 hours, or twice a day.
Cequa is similar to Restasis in the fact that it is composed of 0.09% Cyclosporine. It therefore functions to decrease inflammation and increase natural tear production.
The main difference between Cequa and Restasis is the drug vehicle—Cequa uses a nanomicellar technology, allowing the Cequa drops to penetrate the cornea deeper than Restasis drops do.
The most common side effects of Cequa are irritation upon drop instillation and redness. Other side effects include eyelid inflammation and headaches.
Ultimately, this is a question that your eye doctor will need to answer. There are several tests used to diagnose dry eye disease and help to determine what your eye’s unique individual problem is.
There really is no right or wrong treatment for prescription dry eye drops as each drop is roughly equally effective in studies.
Restasis and Cequa tend to take about 3-6 months for a patient to really notice a different.
Xiidra tends to have a quicker onset in as little as 1 month.
What is most important is to be consistent with using these drops twice a day every day. Only using them once a day, or once every few days, is not helpful. These drops will not help to lessen symptoms unless taken regularly, and therefore cannot be used “as needed” for dry eye discomfort.
Additionally, often times insurance dictates which drop will be tried first, as certain insurances only provide coverage for one of the three options.
If one drop does not work for you, perhaps another one will. It is at least worth a try! Be sure to have this conversation with your optometrist so that he or she can find the drop that works best to manage your symptoms.