All Dryness in Contact Lens Wear

Christopher Snyder, OD, MS
AUGUST 1998

Symptoms of dryness plague many contact lens wearers.  Here's what can be done to restore and maintain lens comfort.

The term "dry eye" encompasses many combinations of clinical signs and patient symptoms, all with varying degrees of severity and periodicity and with many underlying etiologies. In addition, many ocular discomforts are described by patients as dryness, so the symptom of dryness is not necessarily indicative of a dry eye. As a result, the complex dry eye landscape leads to frustration and sometimes misunderstanding for practitioners and researchers. Yet, an accurate diagnosis and understanding of the etiology is the key to effective treatment.

We use the term "marginal dry eye" to indicate a condition where patients experience occasional symptoms of dryness, typically in conjunction with certain activities, times, environments or conditions, but where consistent and absolute signs of dry eye are not present. A diagnosis of marginal dry eye is often associated with contact lens wear.

In follow-up to Dr. Kelly Kinney's article on detecting dry eye in contact lens wearers, published in the May 1998 issue of Contact Lens Spectrum magazine, this article focuses primarily on the clinical management of dry eyes and drying symptoms in contact lens wearers.

The Pre-Fitting Circumstance

Patients with clinical signs and symptoms of dry eye should not be fitted with contact lenses until such signs and symptoms are improved or eliminated. This means that you should have guarded prospects for contact lens success in these patients unless you find problems like meibomian gland dysfunction or blepharitis, which are manageable causes of tear film instability. At the other end of the spectrum, a bandage hydrogel contact lens often provides protective and even therapeutic effects when severe cases of ocular surface disease, aqueous deficient dry eye or evaporative dry eye are putting the eye at risk of severe drying.

If a patient is already wearing contact lenses and is having drying symptoms, treat or manage the contributing factors.

Always Helps

No contact lens wear -- Blasphemy, eh? Actually, this is a better option for patients with truly dry eyes and for those where all management steps fail to provide healthy and comfortable lens wear. This likely means presenting spectacle lens wear as the number one alternative, since dry eye is an apparent residual effect following some of the keratorefractive surgeries, although the reason why is not yet clear.

Treat eyelid problems first -- The oils of the meibomian gland are extremely important for minimizing evaporation of the tear film. Meibomian gland dysfunction can be treated with daily use of warm compresses and eyelid cleansing, either with a wash cloth or commercially available lid scrubs.

Lid margin infection, particularly from chronic staphylococcal blepharitis, can disrupt the tear film. Before continuing with contact lens wear, treat the blepharitis with good lid hygiene -- similar to what you'd recommend for meibomian gland dysfunction -- along with antibiotic ointment.

Rewetting drops -- Supplementing the bulk tears rehydrates the lens and always soothes the eye, even if it lasts for only a few minutes.

Midday re-soaks -- Patients who have hours of comfortable wear but experience drying symptoms later in the afternoon will always find tremendous relief by removing their soft lenses, even for as little as a five minute re-soak in the lens case. This allows the lens to rehydrate and gives the eyes a short break from lens wear. Patients can then reinsert their lenses for many more hours of comfortable wear. Many patients will use this trick for that occasionally long day and evening.

Another option is having a spare pair of lenses ready for that midday switch, although this doubles the number of lenses that require care at the end of the day.

Clean lenses -- Improving compliance with lens care or changing to what may be a more effective cleaning system always seems to decrease drying symptoms and give that extra boost to lens wearing comfort. This works for both RGP and soft lenses, although RGP lenses that build up coatings or have scratches, which destabilize the pre-lens tear film, don't seem to trigger what patients report as drying symptoms. However, RGP contact lens patients who routinely have their lenses cleaned and polished at their annual contact lens checkup marvel at how much better the lenses feel!

More complete and more frequent blinking -- Infrequent and incomplete blinking is devastating to contact lens wearing success, especially with hydrogel lenses. Counseling patients about their blinking habits and encouraging them to blink fully and frequently can really help, particularly for the many patients who use computers for extended periods of time. Concentration on the computer monitor decreases blink rate and blink fullness, increasing tear evaporation. When a hydrogel lens loses moisture, it draws the aqueous component of the tears into the lens, leaving the ocular surface less moist and vulnerable to symptoms of dryness.

A good blinking technique is also very important in RGP lens wearers because an RGP that's not centered or that's inferior in its position is most often associated with drying of the peripheral cornea, evidenced by 3 and 9 o'clock staining. Therefore, full and regular blinks are critical to RGP lens wearing success. A well-counseled and motivated patient can often have some degree of positive effect from blink training.

Environmental "control" -- It is sometimes possible to control a patient's environment, and higher humidity is typically good for enhancing contact lens wearing comfort. When humidity is low, as in aircraft cabins and high altitudes, soft lenses are particularly susceptible to triggering that marginal dry eye circumstance. Recommend that your patients not wear lenses for long airline flights and that they load up on rewetting drops for their winter ski vacation.

Air drafts enhance dehydration of lenses through evaporation, so calm air is an advantage. Tell patients to keep that car heater from blowing in their faces and to turn those ceiling fans down! Contact lenses are also affected by particulate matter in the air -- it gets under RGP lenses and it gets absorbed in soft lenses. Avoiding air contaminated with smoke or other pollutants will always improve the chances of delaying or eliminating ocular discomfort.

May Help

Tear Supplementation -- As I said before, supplementing the bulk tears always soothes the eye and rehydrates the lens. This is universally effective, but the short duration of the positive effect can be discouraging to some patients if they find that they are tempted to reach for their rewetting drops many times each hour.

Rewetting and lens lubricant drops are many and varied. Probably the most significant feature is whether the product is preserved or not. Patients who are sensitive to preservatives or who have allergies may do better with non-preserved products. Occlusion of the nasolacrimal drainage system can extend the relief given by these drops by extending retention time on the ocular surface.

Tear preservation with punctal plugs -- Punctal occlusion is an easy procedure and is helpful in preserving the natural tears. It provides relief for many soft lens patients who have symptoms of dryness, especially those who are diagnosed with borderline or marginally dry eye. Realize, however, that this approach most often works when the dryness symptoms stem from an aqueous tear deficiency, so it may not work well for all patients.

Dissolvable collagen plugs are typically used for a trial to determine if more permanent closure of the puncta would be worthwhile. However, you should be mindful of how powerful suggestion can be to patients. In a study by Lowther and Semes (1995), hydrogel wearers with drying symptoms who had a single collagen plug in both canaliculi of one eye but thought they had the treatment in both eyes indicated that dryness symptoms improved in both the treated as well as the untreated eye. Interestingly, the results of the clinical tests performed to evaluate for dry eye were not different between the treated and untreated eyes at follow-up.

Punctal occlusion using non-dissolvable, silicone plugs may be more effective than occlusion using collagen plugs because of the stability of the silicone material and of the plug dimensions. Silicone punctal plugs are inserted into the punctal opening, are visible and may occasionally induce foreign body sensation. Silicone intracanalicular plugs are inserted down within the canaliculus, so they leave no outward evidence of their presence and do not induce any sensation for the patient. Intracanalicular plugs improve drying symptoms and clinical signs for soft lens wearers, but Slusser and Lowther (1998) caution that the positive effects on symptoms may diminish over time for reasons that are not yet clear. Remember too, that effective lacrimal drainage occlusion enhances the benefits that rewetting drops afford.

More frequent replacement of soft lenses -- It is true that a shorter lens life is better. Newer lenses are cleaner and cleaner lenses wet better and feel better. A caveat, however -- even a lens on its very first day of wear can dehydrate and cause drying symptoms, so frequent replacement may not always bring total resolution to the problem of dryness.

Lens Materials -- If the lens polymer loses water, it will steal the aqueous phase of the tears in which it sits and leave the eye with relatively less moisture and the patient with symptoms of ocular dryness. If lens dehydration is the problem for a hydrogel wearer, consider a change to RGP lenses since they are not susceptible to dehydration. If a hydrogel wearer isn't willing or able to make the switch, consider prescribing a hydrogel of lower water content and thicker design, since it's believed that they're better for minimizing drying symptoms. The reasoning is that lower water content lenses have less water to lose and that the moisture lost from the surface of a thinner lens constitutes a high percentage of the total amount of moisture within the lens.

While many of us still believe in this logic, Jurkus and Gurkaynak (1994) reported a slight preference among 10 marginally dry eye patients for a thinner, 58 percent water content hydrogel lens compared to the same lens material in a 33 percent thicker design. They also reported that the thinner lens was associated with no corneal staining but the thicker lens had a 37 percent incidence of staining. So, our traditional tenets regarding lens material, water content and thickness are still open to debate and further study.

The U.S. Food and Drug Administration has recently permitted the labeling for omafilcon A material, available as the Proclear line of contact lenses, to state that the material may provide improved comfort for contact lens wearers who experience mild discomfort or symptoms relating to dryness during lens wear. This dryness may be associated with an evaporative (non-Sj�gren's) or aqueous tear deficiency. The lens material, incorporating the water-retaining polymer phosphorylcholine, probably won't help every patient, but the recent FDA labeling and the clinical reports to date certainly earn it a spot on our lens material option list.

Drinking more -- Many people do not drink enough water and therefore function in a relatively dehydrated body state. Targeting that quota for daily water intake (eight 8oz. glasses plus one 8oz. glass for every 10 pounds overweight) may have positive benefits on tear production, particularly the aqueous phase. Consider adding this to your list of recommendations to any marginal dry eye patient, contact lens wearer or not.

Symptoms of dryness, whether due to frank dry eye or just that occasional marginal dry eye, will continue to be a routine clinical challenge for eyecare practitioners. Keep in mind that a careful diagnostic work-up is the best place to start. Then consider the management steps offered here -- those that always work and those that may work -- to minimize drying symptoms and maximize patient success with contact lens wear.

References are available upon request to the editors of Contact Lens Spectrum magazine. To receive references via fax, call (800) 239-4684 and request document #39. (Be sure to have a fax number ready.)

Dr. Snyder is a professor of optometry and serves as chief of contact lens patient care at the School of Optometry at the University of Alabama in Birmingham.