Combating Dry Eye in Lens Wearers
Finding the cause and initiating proper treatment can help you keep dry eye sufferers wearing their lenses.
By Julia Geldis, OD, MS
Dr. Geldis is a 2005 graduate of The Ohio State University College of Optometry and completed a two-year Cornea and Contact Lens Fellowship in 2007. She is currently a clinical assistant professor at The Ohio State University College of Optometry and chief of optometry services at the university student health center.
As an optometrist at a university health center for students, I treat and manage contact lens complications resulting from noncompliance daily. I also encounter many unhappy contact lens wearers who aren't satisfied with the comfort their current lenses provide.
Most of my patients spend long hours studying and using the computer, resulting in a decreased blink rate and increasing the risk of dry eye symptoms with contact lens wear. This decreased blink rate and the disruption of tear film stability induced by contact lens wear is the perfect recipe for dry eye disease, or dysfunctional tear syndrome.
Symptoms of dryness and discomfort are leading causes of decreased contact lens wear time or discontinuation of contact lens wear. A cross-sectional survey found that 24 percent of all subjects who had some experience with contact lenses had permanently discontinued contact lens wear and 26.3 percent of current wearers were dissatisfied with contact lens wear. Participants cited dryness and discomfort as the primary reasons for dissatisfaction (Richdale et al, 2007).
Targeting the Causes
An international task force of dry eye experts recently established a treatment algorithm to manage dry eye disease. This treatment algorithm provides the tools to manage dry eye in a more concise, systematic manner based on a patient's dry eye symptoms. While we may apply the treatment recommendations created by the task force to target dry eye in contact lens wearers, no algorithm has been established to specifically target those patients who suffer from contact lens-related dry eye.
It's important to elicit information regarding a patient's lens care and compliance in the first few minutes of the examination. Knowing how our contact lens patients handle and care for their lenses is vital to our treatment and management of their symptoms of ocular dryness and irritation.
Asking a proper case history and digging a little deeper into the habits of contact lens wearers may enlighten us to certain red-flag behaviors that may be contributing to the dry eye symptoms. Not following the prescribed replacement schedule, reusing old solution, using incompatible solutions and/or lubricating drops and infrequent replacement of contact lens cases can certainly lead to poor contact lens comfort and serious ocular complications, including severe microbial infection and possible vision loss.
It's our job to educate and effectively communicate to each of our patients the importance of good contact lens compliance. This communication certainly should be verbal, as words are powerful tools to convey a message. However, supporting the verbal communication with additional handouts, diagrams or even photographs of lens complications may be an effective method to strengthen the message of proper lens care.
Assess the Severity
After establishing the daily care and handling habits of our contact lens patients, it's important to assess the severity of their dry eye symptoms with dry eye testing and/or by having patients complete a dry eye survey or questionnaire. The results of the testing will help guide your approach to treatment.
In addition to your routine slit lamp examination of the anterior ocular surface and routine lid eversion to examine the tarsal plate, the following dry eye tests may be useful in determining the etiology of the dry eye symptoms: tear break-up time (TBUT) and phenol red thread test (Zone-Quick, Menicon) or Schirmer tear test. Because dry eye syndrome is multifactorial in nature, these tests may help determine whether the etiology of the dry eye is predominantly aqueous tear deficient or evaporative in nature. Contact lens-related dry eye is classified as more evaporative in nature because of the instability of the tear film induced by the contact lens on the eye and the resulting increased rate of evaporation.
For those who suffer occasional mild dry eye symptoms, recommend the use of a preservative-free artificial tear 15 minutes before and after contact lens wear, as well as using rewetting drops throughout the day as needed during contact lens wear. The basis behind treatment with artificial tears and rewetting drops is to keep the lens and ocular surface hydrated and/or to maintain a wettable surface to prevent a quick pre-lens tear film thinning time by acting as a surfactant. While the easiest treatment for a practitioner to recommend, rewetting drops may be an inconvenient and costly method to provide short-lasting relief to those who suffer frequent or constant dry eye symptoms secondary to lens wear.
Utilize your knowledge of the different contact lens solutions to recommend a different cleaning, disinfecting and storage system that may decrease dryness and irritation. Certain solutions may induce corneal toxicity and/or hypoesthesia; therefore, a change in solution type may decrease lens-related dryness and increase comfortable lens wearing time.
Changing the solution type to one that has specific lubrication and wetting properties may benefit wearers who suffer from dry eye. The solution lubricant hydroxypropyl methylcellulose (HPMC) can increase pre-lens tear thickness, increase tear thinning time and improve the structure and stability of the pre-lens tear film through qualitative methods. For patients who exhibit an overall diffuse punctate corneal staining pattern consistent with solution toxicity, switching to a hydrogen peroxide system may decrease the amount of keratitis and lead to more comfortable lens wear throughout the day.
A Refit May Be Necessary
More often than not, if a patient is initiating a complaint of dry eye, the condition has already reached a level considered to be moderate or severe. For your patients who suffer from moderate dry eye symptoms secondary to contact lens wear, changing contact lens care systems may not be enough to eliminate dry eye symptoms, and refitting into a different brand or material may be warranted. A low-water-content hydrogel lens may be less likely to result in dry eye symptoms.
Another option is refitting the patient into a lens material that is specifically designed to combat lens-related dry eye. CooperVision's Proclear and Biomedics XC lenses are made of omafilcon A, which is combined with a synthetic analogue of phosphorylcholine, a naturally occurring phospholipid. This surface may resemble the cell membrane of human cells and is thought to combat dry eye by mimicking the structure of naturally occurring membrane surfaces, with water molecules surrounding the phosphorylcholine molecules, to provide greater comfort and less lens-related dryness.
A study by Lemp et al (1999) found statistically significant improvements in a number of parameters, including contact lens comfort, symptoms of dryness, the frequency of ocular burning and irritation, and corneal fluorescein staining as well as less on-eye dehydration with the omafilcon A material. The omafilcon A material is now available in a daily disposable lens modality as the Proclear 1 Day.
Hydrogel Vision Corp's Extreme H2O line of lenses is also designed to combat lens-related dryness, but doesn't have an FDA indication. The omafilcon A material does carry an FDA indication for reducing contact lens-related dryness.
While refitting into a daily disposable lens may not be a practitioner's first choice when treating dry eye symptoms, daily disposable lenses certainly have a role in managing contact lens-related dry eye and are not recommended frequently enough. Refitting into a daily disposable lens is an excellent choice and, in my opinion, the best clinical decision you can make to ensure optimal ocular health and contact lens comfort in those patients who suffer from ocular irritation induced by allergens or who are prone to heavy lens deposition.
A number of brands are available in a daily disposable modality. Two daily disposable lenses incorporate agents into the material to help combat lens-related dryness. Acuvue 1-Day Moist (Vistakon) incorporates Lacreon technology, which embeds a water-holding ingredient, polyvinyl pyrrolidone (PVP), similar to that found in natural tears, into the etafilcon A material. Focus Dailies with AquaRelease (CIBA Vision) is a polymer of nelfilcon A material infused with polyvinyl alcohol (PVA) as a lubricating agent, which is gradually released from the contact lens during wear.
The daily disposable modality seems to be taking a bigger role in treating and managing dry eye symptoms and ocular irritation in lens wearers.
Investigating Severe Cases
Contact lens wearers who suffer from more severe dry eye symptoms warrant more serious investigation into the etiology of their dry eye symptoms. In those patients who exhibit dry eye with a phenol red thread or Schirmer tear test, suspect aqueous tear deficiency to be the source of the dry eye symptoms. In this case, you may consider punctal occlusion to treat dry eye, as long as lid inflammation has been properly treated. However, if any inflammation is present, it may be prudent to consider other forms of dry eye management first, such as prescribing a low-dose steroid for two weeks to decrease ocular inflammation. If the low-dose steroid improves symptoms, consider prescribing Restasis (Allergan) to increase tear production and to avoid the build-up of inflammatory mediators on the ocular surface that punctal occlusion may otherwise bring.
If TBUT is less than 5 seconds and phenol red thread test results are greater than 10mm in 15 seconds or Schirmer testing is greater than 5mm in five minutes, suspect evaporative dry eye to be the primary cause of the symptoms of dryness and irritation. It's important to treat any blepharitis and/or meibomian gland dysfunction if present, as these conditions are common causes of evaporative dry eye syndrome.
I advise my patients who exhibit lid margin disease to temporarily cease contact lens wear until further advised and to begin a daily regimen of lid scrubs and warm compresses.
I advise using SteriLid (Advanced Vision Research) for gentle cleansing of the lids instead of a baby shampoo because the shampoo may irritate the ocular surface further. The key ingredient in SteriLid is linalool, a naturally occurring liquid distilled from plant oils, that gently cleans the lid margins while helping maintain the oils of the skin that have antibacterial properties. It also helps maintain the skin's natural defense against bacteria and other toxins that can contribute to meibomian gland dysfunction and lid disease.
If your patient is noncompliant with the daily regimen of lid scrubs and warm compresses or if you see no improvement, consider prescribing oral tetracycline therapy or recommending omega-3 fatty acid supplements to improve meibomian gland function and tear stability.
Well-Armed to Fight Dry Eye
Unfortunately, there is not one guaranteed treatment plan to eradicate dryness, burning, grittiness, and ocular irritation in our lens patients. However, using the knowledge of contact lens brands, materials and care systems available to us, as well as keeping current with the ophthalmic literature, ensures we will be well-equipped with the proper tools to manage our dry eye contact lens wearers.
When a simple change in care system or material does not effectively decrease frequency or intensity of symptoms or does not eliminate symptoms completely, a temporary cessation of lens wear, proper dry eye testing and treatment specifically targeted to the etiology of the symptoms are warranted.
Effectively communicating with and educating all patients on proper contact lens care will increase the chances of your patients being compliant, happy contact lens wearers and will decrease the chance of patients experiencing ocular discomfort and infection associated with contact lens wear. CLS
For references, please visit www.clspectrum.com/references.asp and click on document #152.