Knowledge - Treatment - Relief

    Preview the eBook by reading Chapter Four: Artificial Tears

Chapter Four: Artificial Tears

The goal of artificial tears is to supplement your own natural tears. This is generally the first line of treatment for dry eye, and most dry eye sufferers are accustomed to using them. The most common mistake made by those using artificial tears is waiting for the symptoms to appear before using the drops. It is much better to instill drops before the symptoms appear, thereby prohibiting or diminishing the effects of dryness. This strategy is most effective for those whose dryness is primarily related to their environment such as heavy computer users or those who work outdoors in windy areas.

Many patients state that they don't need artificial tears because their eyes already produce extra tears, often to the point that they are watery. Excess watering are your eyes compensating for the dryness and is a reflex response to dryness. If you experience this, you are already dry and should have started your artificial tears earlier.  If your eyes water, it is important to get artificial tears started to stabilize the natural tear film since the reflex tears are washing out the normal three layer system and perpetuating the problem.

There are many brands of artificial tears, some are better than others. One study showed many patients tried more than three brands of drops prior to seeing their eye doctor for dry eye. There is no single "best" drop. No drop can correctly imitate the complexity of the normal tears. The most important thing is which one or ones are the best for you. Remember, the tear film consists of three layers. Different tears target different layers. If the drop you use doesn't target your problem area then it is not the best for you.

How do you know which ones to use? There are two methods. First, certain problems of the tear film must be identified. Once pinpointed, it allows you to target the problem with a certain class of drops. This should be diagnosed by your doctor and is often difficult for them to identify correctly. The second method is trial and error. This means trying one drop after another until you find one that works for you. This can be costly and time consuming. It is also frustrating and delays finding real relief. Below the most effective drops are categorized by how they work. You can dramatically narrow down the number of drops you try by testing drops from each class rather than randomly trying them all.

Each class of drops discussed includes several good drops to try. There are many different brands and it would be impossible to cover them all. Listed are some of the most effective. Most drops are based on good science and the manufacturers spend tremendous amounts of money telling consumers why theirs is the best. The goal of this book is not to tell you which one is the best because there are many good ones. It teaches you what the categories are and brands in each one. Remember, the most important thing is finding which drops are the best for your eyes.

Here are the categories of tears in no particular order:


Hypo-osmotic tears

Within the water layer of the tears are many components including salt, proteins and electrolytes. When the tear volume decreases either through reduced tear production or increased tear evaporation the ratio of these components and tear fluid become unbalanced, causing your tears to become hyper-osmotic. This hyper-osmotic state promotes inflammation and worsens a whole host of conditions in the tears and on the eye surface. Hypo-osmotic tears work to restore the normal delicate balance and decrease the cycle of dryness.

Drops in this class include: Theratears, Hypo-tears, Akwa Tears


Lipid Restoration

The top layer of the tear film consists of lipids. This layer helps to protect against evaporation. Deficiency in this area is usually caused by meibomian gland dysfunction (MGD). We will talk later about addressing MGD specifically. These drops are designed to compensate for this deficiency by supplementing the lipid layer of the tears. By supplementing for inadequate lipids, these drops help restore the top layer to its normal function, thus improving integrity of the tear film and decreasing evaporation. Current research indicates diminished lipid production is one of the leading causes of dry eye. Improving this layer when deficient is very important.

Drops in this class include: Soothe XP, Systane Balance, Tears Again Advanced Liposome Spray


Tear layer restoration and lubrication

This category is one which has many drops available over the counter. In fact there are so many it is not practical to list them all, but a few are mentioned below. These have their place in dry eye treatment which is to temporarily decrease discomfort by increasing  tear volume. Most of these will make your eyes feel better. Some are better than others and some last longer than others. Drops in this category have the following molecules in them: Propylene Glycol, Glycerin, Polysorbate, Carboxyl Methylcellulose, Hydroxypropyl Methylcellulose, Dextran, and Polyethylene Glycol.

You will find out which drops you like in this category mainly by trying them. Ask your eye doctor for samples of these before purchasing them, the costs can add up quickly. Manufacturers do a pretty good job of keeping doctors supplied with samples so take advantage of it. Remember, the most effective drop is whichever one works the best for you.

Drops in this class include: Refresh Optive, Refresh Tears, Systane, Blink, and Genteal


Homeopathic

For some, the molecules listed above remind them too much  of names they learned in chemistry class. Others prefer more natural tears and only want non-synthetic drops going into their eyes. For those there are homeopathic drops available. These also fall under the heading of Tear Layer Restoration and Lubrication.

Drops in this class include: Similison, Optique, Nature's Tears Eyemist


Gels versus Liquids

There are several brands of Gels available. They usually consist of ingredients already discussed, only in a thicker form. Their goal is to last longer in the eye. Many people like them while others don't like the feeling they get with them or the initial blurry vision they cause. Their goal is to provide longer lasting relief than ordinary drops.

Drops in this class include: Refresh Liquigel, Genteal gel


Ointments

These are generally reserved for more severe conditions and are most often used at night. They keep the eyes lubricated for a longer period of time while sleeping.

Brands in this category include: Refresh PM, Refresh Lacrilube, Genteal PM


Freshkote

Freshkote is an artificial tear available by prescription only. It attempts to target all three layers of the natural tear film by including components beneficial to each layer within a single bottle. It does this by providing higher concentrations of treatment than over-the-counter drops. It is similar to taking a prescription strength ibuprofen. While it has worked well for some people, it doesn't benefit everyone.


Lacrisert

Lacrisert needs to be discussed in a category by itself. The package insert describes it this way:

Lacrisert is a sterile, translucent, rod shaped, water soluble, ophthalmic insert made of hydroxypropyl cellulose, for administration into the inferior cul-de-sac of the eye.

It is similar in size and shape to the end of a pencil lead. It is approximately 1.27mm in diameter and 3.5mm long. It is placed behind the lower eye lid using a special applicator included in the package. It is preservative free. The goal is to have an extended release of the molecule to maintain a steady flow on the eye without regular instillation of drops.

A recent study involving over 400 participants showed Lacrisert can decrease dry eye symptoms in moderate and severe cases. In the study, the number of patients who previously reported having severe dry eye symptoms decreased to moderate symptoms by 30%. 19% of those who scored as moderate dry eye decreased to mild. Some patients are not successful with daytime use due to experiencing a foreign body sensation. For those, they might benefit from using it at night while sleeping. This method provides a constant release of artificial tears aiding those who suffer from dry eye associated with sleep.

It is by prescription only and should be discussed with your eye doctor to determine if you are a good candidate.


Preservatives


This is a very important consideration. Any bottle that has a screw on cap that is replaced after use will have a preservative. The purpose is to protect the drop from contamination so it can be safely used repeatedly over time. Preservatives are safe and serve a vital role with all repeated use drop containers. However, you need to limit your exposure to them to about 4-5 drops per day. More than that and the preservatives can worsen the irritation to the cornea, the same thing you are trying to treat.

Most packages will clearly state if they are preservative free. Some drops have what is called a "disappearing preservative" which means once the drop contacts the eye surface it breaks down into water. There is one way to know for sure if it is free of preservatives. If the drop comes in an individual single dose vial which is discarded after use then it doesn't have preservatives.

The preservative benzalkonium chloride (BAK) receives significant attention and deserves its own discussion. BAK is likely the most effective preservative at resisting microbials and one of the most commonly used in eye drops. Nevertheless, it has been shown to be toxic to corneal tissues with frequent dosing. With low frequency use it is considered safe. However, there are problems with dry eye sufferers using it. Anything more than just mild dry eye will compromise the cornea, making it more likely to be adversely affected by BAK. Also, the decreased tear volume diminishes the ability to properly dilute BAK once applied to the cornea.

Many dry eye sufferers use eye medications for other conditions such as glaucoma. Most medications are preserved with BAK. Dry eye sufferers should avoid it as much as possible. If you must use a medication with BAK (for dry eye or any other condition), minimize the amount coming into contact with your eyes by ensuring that every other drop, where you have a choice, is preservative free. Any pain, redness, or foreign body feeling after instilling BAK preserved drops should be discusses with your eye doctor.


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