Beating Back SAC
contact lens management
Beating Back SAC
Daily disposable lens offers relief for allergy sufferers
MARY JO STIEGEMEIER, O.D., MARY FAHMY, O.D. AND SHARON HOLDEN THOMAS
Because contact lenses can act as a reservoir for allergens — prolonging their contact with the ocular surface — wearers are particularly vulnerable to Seasonal Allergic Conjunctivitis (SAC).
Ocular itching and burning are common SAC symptoms. The condition's ocular signs include watery discharge, papillary hypertrophy and conjunctival chemosis and injection.
Management of wearers who suffer from SAC symptoms typically includes avoidance of the offending allergen (often a pollen), lubricating and/or therapeutic ocular allergy drops, cold compresses, reduced wearing time, more rigorous lens care regimen and increased frequency of lens replacement. Once lens wear becomes uncomfortable for SAC patients, they often choose to cease wearing contact lenses.
Dailies AquaComfort Plus, a next-generation Dailies lens from CIBA Vision, however, may help allergy patients to continue wearing lenses. Like it's predecessor, Dailies AquaComfort Plus is made of nelfilcon A, a non-ionic, polyvinyl alcohol (PVA)-based polymer. PVA is a blink-activated moisturizing agent that provides end-of-day comfort. In addition, the lens contains hydroxypropyl methylcellulose (HPMC), a lubricant that provides instant comfort at the start of the day; and polyethylene glycol (PEG), a hydrophilic wetting agent that works with PVA to provide moisture throughout the day. Also, Dailies AquaComfort Plus wearers begin each day with a fresh lens, ensuring an allergen-free surface.
In 2001, the Food and Drug Administration (FDA) cleared original Focus Dailies one-day contact lenses for reducing the symptoms of SAC in contact lens patients after a 10-site clinical trial of 112 wearers with the condition revealed decreased reports of burning and redness in patients who wore them.
Dailies AquaComfort Plus
MATERIAL: Nelfilcon A
WATER CONTENT: 69%
WEARING SCHEDULE: Daily Wear
SCHEDULE: Daily Disposable
BASE CURVE: 8.7mm
SPHERE POWERS: +0.50 to +6.00 in 0.25D steps; -0.50 to - 6.00 in 0.25D steps; -6.50 to - 10.00 in 0.50D steps.
PATIENT COST: $28 to $60
To demonstrate that wearers who have SAC experience decreased subjective symptoms of the condition when wearing Dailies AquaComfort Plus, CIBA Vision began a one-month, open-label, 10-site clinical trial in Spring 2007. The trial consisted of 145 subjects who had definite or presumed SAC and wore soft daily wear contact lenses, which they replaced at intervals of two-weeks or longer.
The trial protocol defined "definite SAC" as a history of seasonal allergy, in which the investigator's office (one of the sites) previously observed and/or managed signs and symptoms related to those allergies. The protocol defined "presumed SAC" as a history of seasonal allergy given by the patient, in which the investigator's office didn't observe or previously manage SAC signs and symptoms.
The researchers randomly divided the participants into two groups: those who wore a new pair of their habitual lenses on a daily wear basis (71 subjects), and those fit in Dailies AquaComfort Plus and wore them on a daily wear, daily disposable basis (75 subjects). Subjects in the habitual group continued to replace their lenses at their prescribed replacement schedule and use their habitual lens care system.
The researchers didn't permit the participants to use over-the-counter (OTC) or prescription ocular medications during the trial, though the subjects were allowed to use OTC or prescription oral, inhaled or injected medications not contraindicated for the soft contact lenses that they used during the trial.
The trial included a baseline/enrollment visit and a final visit at the one-month mark. At the baseline visit, participants completed a questionnaire assessing ocular symptoms, such as itching, burning, redness and watering, that they experience during allergy season. In addition, they kept a daily diary of symptoms experienced during the trial period.
At the end of the trial period, researchers compared the percentage of days the subjects experienced each symptom between the Dailies AquaComfort Plus group and the habitual daily wear lens group.
Results revealed that overall, the group wearing Dailies AquaComfort Plus experienced a statistically significant reduction in the percentage of time that they had stinging (3.3% v. 8.3%), redness (7.1% vs. 15.0%) and watering (4.3% vs. 11.1%). Patients in the habitual daily wear lens group tended to experience burning and itching a higher percentage of time than those in the Dailies AquaComfort Plus group, although the researchers found no statistically significant differences regarding these symptoms (burning, 6.1% vs. 9.3%; itching, 14.1% vs. 20.7%).
The results of this month-long trial show that patients who have SAC fit in Dailies AquaComfort Plus experienced a reduction in the frequency of some of their symptoms. The combination of a nonionic, daily disposable lens with three moisturizing agents and proven comfort appear to provide welcome relief for many allergy sufferers. The bottom line: Fitting these patients in Dailies AquaComfort Plus may prevent many of them from dropping out of lens wear. OM
DR. STIEGEMEIER IS IN PRIVATE PRACTICE IN BEACHWOOD, OHIO. SHE LECTURES THROUGHOUT THE COUNTRY ON THE SUBJECT OF CONTACT LENSES AND PERFORMS CLINICAL RESEARCH. E-MAIL HER AT IMDOCSTIEG@AOL.COM.
DRS. FAHMY AND THOMAS ARE SENIOR PRINCIPAL CLINICAL SCIENTISTS WHO PERFORM CLINICAL RESEARCH AT CIBA VISION WORLDWIDE HEADQUARTERS IN DULUTH, GA.
Optometric Management, Issue: September 2008