I love dry eye. There. I said it, and I don’t care who knows it. I find dry eye to be one of the most interesting and challenging aspects of optometry. What others see as a nuisance and a waste of their time, I embrace as an opportunity to share my expertise and alleviate patients’ functional visual health issues. What can I say? I’m a dry eye geek!

As I travel around the country, I’m often asked my thoughts regarding the myriad over-the-counter treatment options for dry eye. This is not an easy topic to tackle. There are many fine artificial tear products on the market today; moreover, the “best” option for one patient is likely not the best option for another. This judgment is based upon numerous factors, including the underlying disease etiology, tear composition and pH, corneal integrity, blur tolerance, and a variety of other factors.

With time and experience, however, I’ve developed an algorithm of sorts that helps me logically prescribe the appropriate tear formulation for a given type of patient. This article reviews my thought processes and recommendations in that regard. And, for the record, I have no direct financial interest in any of the products (or their respective companies) discussed in this article.

Choose the Right Product
Dry eye stems from either a quantitative or qualitative reduction in normally secreted human tears, or because of circumstances that facilitate more rapid evaporation of tears from the ocular surface.

Past experience suggests that quantitative issues in the form of true lacrimal insufficiency are relatively uncommon in clinical practice. More often than not, patients experience dry eye complaints due to enhanced evaporation caused by a deficient lipid tear component, dysfunctional mucin component, irregular ocular surface or poor lid-globe apposition and dynamics. So, one of the first goals in managing dry eye is replenishing or augmenting the tears with a lubricant drop.

Our ideal artificial tear should provide fast, effective and prolonged relief. It should be comfortable immediately upon instillation, and it should induce minimal blurring. Don’t forget: The product should be convenient to use, and should ideally have the ability to improve objective signs of dry eye as demonstrated by impartial clinical trials.

While that “perfect” artificial tear may not exist, some are far better than others. In practice, we should prefer science over marketing hype. Look for those products that can clearly show improved patient satisfaction and clinical superiority based upon well-designed prospective studies presented in an open forum.

Practitioners must realize that artificial tear products need only conform to the guidelines in the U.S. Food and Drug Administration’s OTC monograph in order to be sold in the U.S., which does not require individual studies be conducted or submitted for review. So, I tend to favor those products whose companies go the extra mile to demonstrate compatibility or superiority. Of course, personal experience plays a big role, too. If I get a good response from the majority of the patients to whom I prescribe a particular product, I’m inclined to continue to prescribe that product.

What, Where and When?
It’s likely easiest to discuss recommendations for dry eye based on the specific product. Here, I’ll review my five most commonly used tear products (in no particular order): Refresh Optive, Blink Tears, Systane Ultra, Soothe XP and FreshKote.

• Refresh Optive (Allergan) is an aqueous suspension that contains the active ingredients 0.5% carboxymethylcellulose (CMC) and 0.9% glycerin. Optive is preserved with Purite, a proprietary element that dissipates upon contact with the ocular surface and may have a less deleterious effect than other, harsher preservatives.

In practice, Optive is my workhorse; I use this drop for the vast majority of patients with mild or intermittent dry eye complaints. It is gentle and comfortable, and the CMC ensures good comfort and reasonable retention on the ocular surface. Patients with computer-associated dry eye or those who experience sporadic symptoms in specific locations (e.g., on airplanes or in dusty environments) usually fare quite well with Optive. In a recent trial of more than 5,000 dry eye patients, 75% reported improvement in clinical signs and symptoms after using Optive for two to four weeks.1 In another study, patients using Optive for a month showed a significant improvement in staining, Schirmer’s score and the Ocular Surface Disease Index questionnaire.2

• Blink Tears (Abbott Medical Optics) is another dry eye product with broad utility. Like Optive, it is a transiently preserved, minimal-viscosity lubricant drop. The active ingredient is 0.25% polyethylene glycol 400, but the inactive ingredient—hyaluronic acid (HA)—makes Blink Tears unique. Though relatively new in the U.S., HA has been used for many years in Europe as a dry eye therapy, and there is a fair amount of literature detailing its benefits.3-6 A long-chain polysaccharide molecule, HA imparts significant elasticity to the solution, increasing the residence time of Blink Tears on the ocular surface. I tend to use Blink in those patients who have more persistent dry eye complaints or those who require too-frequent administration of Optive or similar drops to control their symptoms.

• Systane Ultra (Alcon) is a formulation of polyethylene glycol and propylene glycol, preserved with Polyquad. Once again, however, it is the inactive ingredients that make it unique. This product contains HP-guar and borate, which upon instillation bind together to form a mesh-like coating over the ocular surface, simulating the epithelial glycocalyx. Once formed, the HP-guar matrix serves as an anchoring bandage, protecting the epithelium and allowing the other components to hydrate and lubricate the damaged cells. Research has shown that Systane helps to improve not only dry eye symptoms, but that it also extends the tear film break-up time and promotes resolution of corneal staining.7-9

Systane Ultra is my tear of choice for patients who present with moderate dry eye symptoms and notable keratopathy. In other words, if there is any significant staining of the cornea with either sodium fluorescein or lissamine green, I start therapy with Systane.

• Soothe XP (Bausch + Lomb) is one of only a handful of products that contain lipids, a key component of the natural tear film that is absent from most artificial tear formulations (others that contain lipids include Refresh Dry Eye Therapy Sensitive [Allergan], formerly marketed as Refresh Endura, and FreshKote [Focus Laboratories]). Specifically, Soothe XP utilizes Restoryl, a proprietary formulation of mineral oils designed to closely approximate the tear lipids.

This combination is particularly beneficial in those patients with dry eye secondary to meibomian gland dysfunction (MGD). Studies conducted by highly respected scientists like Donald Korb, O.D., support the use of this product.10-11

Because this drop helps to replenish the specific tear element that is deficient in MGD, I tend to use Soothe XP as first-line therapy for these patients; of course, I simultaneously attempt to restore the integrity of the glands by using warm compresses, AzaSite (azithromycin 1%, Inspire), oral doxycycline, omega-3 supplements, or a combination of these therapies. It is important not to confuse Soothe XP and Soothe (B+L); the latter does not contain oil, but rather, it is an aqueous solution containing glycerin and propylene glycol.

• FreshKote (Focus Laboratories) has been the subject of many practitioners’ questions of late. It is probably the most unique new product to be marketed for ocular surface disease in the last five years. FreshKote boasts a high colloidal osmolality (oncotic pressure) using a proprietary combination of conventional ophthalmic demulcents, which effectively creates an osmotic gradient away from the cornea. The benefits of this property could be debated in true dry eye disease, but the design seems perfectly suited for ocular surface conditions that manifest superficial or microcystic corneal edema. Additionally, FreshKote contains a proprietary combination of phospholipids, polysorbate-80, glycerin and ethanol, which acts as a dispersing and lubricating agent, much like the lipid layer of the tears.

I find this combination of osmotic potential and enhanced lubrication to be suited for the management of various corneal dystrophies (e.g., granular or lattice), anterior basement membrane disease, recurrent corneal erosions, corneal abrasions and contact lens overwear—essentially, any situation in which 5% sodium chloride solution would be desirable but probably poorly tolerated over the course of the day.

There are scores of artificial tears available to today’s consumers. Certainly, not all are created equal. By having some idea of the utility and specific applications of the various formulations on the market, we can take a more proactive stance in prescribing these agents for our patients with dry eye disease.

As stated above, Dr. Kabat has no direct financial interest in these companies or products. Dr. Sowka returns next month.

1. Kaercher T, Buchholz P, Kimmich F. Treatment of patients with keratoconjunctivitis sicca with Optive: results of a multicenter, open-label observational study in Germany. Clin Ophthalmol. 2009;3:33-9.
2. Kislan T, Rajpal R. Evaluation of Optive in patients previously using Systane for the treatment of dry eye signs and symptoms. Poster presented at the American Academy of Optometry; Anaheim, CA. October 2007.
3. Johnson ME, Murphy PJ, Boulton M. Carbomer and sodium hyaluronate eyedrops for moderate dry eye treatment. Optom Vis Sci. 2008 Aug;85(8):750-7.
4. Prabhasawat P, Tesavibul N, Kasetsuwan N. Performance profile of sodium hyaluronate in patients with lipid tear deficiency: randomised, double-blind, controlled, exploratory study. Br J Ophthalmol. 2007 Jan;91(1):47-50.
5. Johnson ME, Murphy PJ, Boulton M. Effectiveness of sodium hyaluronate eyedrops in the treatment of dry eye. Graefes Arch Clin Exp Ophthalmol. 2006 Jan;244(1):109-12.
6. Brignole F, Pisella PJ, Dupas B, et al. Efficacy and safety of 0.18% sodium hyaluronate in patients with moderate dry eye syndrome and superficial keratitis. Graefes Arch Clin Exp Ophthalmol. 2005 Jun;243(6):531-8.
7. Ousler GW, Michaelson C, Christensen MT. An evaluation of tear film breakup time extension and ocular protection index scores among three marketed lubricant eye drops. Cornea. 2007 Sep;26(8):949-52.
8. Christensen MT. Corneal staining reductions observed after treatment with Systane. Adv Ther. 2008 Nov;25(11):1191-9.
9. Versura P, Profazio V, Campos EC. One month use of Systane improves ocular surface parameters in subjects with moderate symptoms of ocular dryness. Clin Ophthalmol. 2008 Sep;2(3):629-35.
10. Scaffidi RC, Korb DR. Comparison of the efficacy of two lipid emulsion eyedrops in increasing tear film lipid layer thickness. Eye Contact Lens. 2007 Jan;33(1):38-44.
11. Korb DR, Scaffidi RC, Greiner JV, et al. The effect of two novel lubricant eye drops on tear film lipid layer thickness in subjects with dry eye symptoms. Optom Vis Sci. 2005 Jul;82(7):594-601.