DAILY DISPOSABLE LENSES

Seasonal Allergy Relief with Daily Disposable Lenses

By Mary Jo Stiegemeier, OD, FAAO, and Stuart Thomas, OD
April 2001

An FDA classification allows a single-use lens to claim relief with seasonal allergic conjunctivitis.

The spring allergy season is underway in many regions of the United States, and patients are appearing with an array of complaints, symptoms and signs. Seasonal allergic conjunctivitis (SAC) symptoms of itching, burning, watering and redness along with signs such as secretions, upper and lower lid papillary hypertrophy and conjunctival swelling are common findings.

Allergy season may be seasonal for some patients and year-round for others. Allergic eye disease of all types occurs in 20 to 30 percent of the U.S. population, with about half being SAC. Perennial allergic conjunctivitis (PAC), which is the year-round, chronic disease, is estimated to occur in less than 1 percent of allergy sufferers. Based on the 2000 U.S. census, this translates into 20 to 30 million people who suffer from SAC or PAC.

Both SAC and PAC have similar physiologic mechanisms as Type I allergy reactions. They occur when a specific antigen reacts with a specific IgE antibody on a mast cell or basophil that has been previously sensitized. This specificity can give relief to some SAC sufferers as antigens vary with the seasons. The American Academy of Allergy, Asthma & Immunology's (AAAAI) timeline of pollen seasons predicts that tree pollens are highest in winter and early spring months. Grass pollens overlap with spring and summer peaks. Ragweed season then rolls in with highest levels from spring through summer and early fall. Some pollens have limited regional effect such as saltbush in the spring in western states and Florida. Sage peaks in the summer and Russian thistle in the summer in western states. Historical and actual pollen counts from 63 monitoring sites in the United States can be found online from the National Allergy Bureau's portal on the AAAAI website at http://www.aaaai. org/.

Patients with allergies often have developed strategies for managing their symptoms, and they are constantly seeking new ways to get relief. Many contact lens wearers who have ocular allergies don't want to give up contact lenses, leaving their eyecare practitioner with a challenge for management and reducing their complaints. Eye drops, cold compresses, reduced wearing time, changing from chemical lens care systems and increasing lens replacement frequency are strategies that many recommend. Contact lens wearers who have ocular allergies would cooperate with and appreciate any recommendation that could reduce their symptoms and discomfort.

The strategy of frequent replacement has been supported with some research-based findings that report the benefit of changing lenses more frequently as an effective way to reduce some complaints and symptoms. Part of this strategy is to reduce exposure to deposits from tears and airborne allergens. This strategy is sometimes combined with using a non-ionic material to maximize the benefit of lower deposits. The logical endpoint of this approach is to use a non-ionic daily disposable lens. This is the approach that was taken in a study that has resulted in a new claim for CIBA Vision's Focus Dailies daily disposable contact lens. The FDA has approved these lenses for reducing the symptoms of SAC.

Focus Dailies consists of a non-ionic, high water polymer. The main polymer constituent is polyvinyl alcohol (PVA) which has been used in many biomedical applications. PVA has been used in tear supplements as it has been found to promote tear film stability and lens wetting.

Methods

Investigators from 10 sites well-distributed across the United States were asked to enroll 10 to 12 contact lens wearers who had definite, presumptive or indeterminate SAC. The study was timed to take place during the spring high pollen season according to the AAAI's historical data. Retrospectively, pollen counts were reviewed for reporting stations nearest the study sites, and high levels during the study period were confirmed.

Some 112 contact lens wearers were enrolled. Half were randomized to get a new supply of their habitual lenses, and half were randomized to be fit and dispensed in Focus Dailies for daily disposable wear. The range of pre-study replacement schedules for habitual lenses is shown in Table 1, which also lists the subsequent distribution of pre-study replacement schedules among patients in the study. No statistically significant difference was found in the distribution of replacement schedules between the two study groups.

At baseline, patients filled out a symptom history questionnaire, and investigators took additional history from interview and patient files to confirm that each patient had symptoms, signs or history of SAC. In the symptom questionnaire, patients were asked how often they experienced specific SAC-related symptoms. The study groups were compared for differences in these symptoms and no difference was found (Table 2). The investigator's history of each patient's SAC was also compared for the study groups and no differences were found (Table 3). Other patient profile information is given in Table 4. The profile characteristics for each study group were also compared and no statistically significant differences were found.

No changes to the normal strategies for dealing with SAC were made during this study other than using Focus Dailies lenses. Patients were allowed to continue using their usual OTC or prescription medications and any other habitual practices.

The study started in April and ran through early June. Patients kept a diary in which they noted their symptoms, particularly the SAC-related symptoms of itching, burning, redness and watering along with whether they wore lenses and their average wearing time each day. The SAC symptoms were also added to produce a daily symptom sum with presence for each symptom being given a 1 and absence a 0. This could produce a total daily SAC symptom sum of 4 if all symptoms were present, 3 if there were only three symptoms and on down to 0 if there were no symptoms. These data were analyzed and compared between the study groups.

Results

Fewer patients who wore Focus Dailies reported the symptoms of burning and redness than did those who wore a new supply of their habitual lenses. No statistically significant differences were found for the symptoms of itching and watering. Patients who wore Focus Dailies also had fewer total SAC symptoms overall. Patients who wore Focus Dailies tended to wear their lenses a few minutes less than patients who wore their habitual lenses, but no statistically significant differences existed between the study groups for average daily wearing time.

We analyzed a subset from the overall study group that consisted of patients whose history included always experiencing one or more of the SAC symptoms of itching, burning, redness and watering. This subset contained 31 patients who wore Focus Dailies and 29 patients who wore new habitual lenses. Fewer of these patients who wore Focus Dailies reported the symptoms of burning, redness and, additionally, watering than did those who wore a new supply of their habitual lenses. The Focus Dailies wearers also had fewer total SAC symptoms overall. The average daily wearing time between the groups for this subset was again statistically different with slightly more daily lens wearing time being reported in the Focus Dailies group.

The data for all patients and for the subset of patients who had a history of always experiencing one or more of the major symptoms of SAC is summarized in Table 5.

Conclusion

Whether allergy season for your contact lens patients is in the spring, fall, winter or year-round, they all want relief from the symptoms that make contact lens wear uncomfortable. The Focus Dailies lens is highly rated for comfort by non-symptomatic wearers. Practice-based experience has indicated that this lens may help patients with many types of sensitivity problems. This study has found that SAC sufferers may experience fewer symptoms when wearing this daily disposable lens. Recommending an option that increases patient satisfaction with contact lens wear can differentiate your practice and lead to more referrals and practice growth.

Acknowledgement: The protocol, monitoring and data management for this study were provided by Global Clinical Affairs, CIBA Vision Corporation, Atlanta, Georgia, USA.

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