The use of 1-Day Acuvue in patients reporting dry, sensitive or easily irritated eyes

The sensation of dryness is one of the most common symptoms of contact lens wear, experienced by as many as three out of four wearers.1-3 Dryness is also a major cause of discontinuation from contact lens wear; around a half of contact lens drop-outs cite discomfort as the principal reason for having given up contact lenses and the most common type of discomfort is dryness.4 Improved comfort and relief of dryness symptoms have also been shown to be the primary factors that would improve contact lens wear for those who have discontinued.5
The diagnosis of dry eye is elusive, at best, and further characterisation of patients who suffer symptoms of dryness or irritation in conjunction with contact lens wear is even more difficult. Eye care practitioners and researchers increasingly recognise that often the best criterion for diagnosing contact lens-related dry eye is agreement by the subject that they suffer from symptoms of dryness. Begley et al6 recently reported that patient-reported symptoms correlated more highly with practitioner grading of dry eye than did clinical signs.
Practitioners typically consider lens factors such as material properties, water content and thickness when selecting the best soft lens option for patients reporting symptoms of dryness and irritation. However, the importance of replacement frequency and avoidance of deposit-related complications should not be underestimated.
A survey of more than 1,000 soft lens wearers found that symptoms of dryness and end of day comfort were better with one-day and two-weekly replacement lenses than with monthly systems.7 Daily disposable lenses offer the additional advantage of contact lens wear free from cleaning and disinfection, and any potential problem with solution sensitivity.
Numerous studies have shown daily disposables to have significant advantages over other modalities among a general population of lens wearers.8-13 Daily disposable lens wearers benefit from improved comfort, better vision, increased wearing time and fewer unscheduled visits when compared with those using conventional daily wear soft lenses and experience fewer and less serious lens-related complications and symptoms, as well as fewer lens surface deposits.
The use of daily disposable lenses has also been shown to be an effective strategy for managing allergy-suffering contact lens wearers.14,15 A recent study showed that for two out of three allergy sufferers, 1-Day Acuvue (Johnson & Johnson Vision Care) provided improved comfort and reduced slit-lamp findings compared to their habitual, re-usable lenses.15
Introduced to the UK market in 1995, 1-Day Acuvue was the world's first daily disposable contact lens. In 2001, modifications were incorporated to the lens design to further improve its comfort and handling characteristics while maintaining fitting performance. A major study was conducted to compare the clinical performance of 1-Day Acuvue against a range of other daily disposable lens types.16 The lens was shown to provide improved performance and was also preferred by patients for overall choice overall comfort, comfort on insertion, performance in dry environments and longest comfortable wearing time.
The clinical performance of daily disposables among contact lens wearers reporting symptoms of dryness and irritation has not been widely covered in the literature. The purpose of this further analysis of the previous study16 was, therefore, to evaluate the use of 1-Day Acuvue among those patients who were self-identified sufferers of dry, sensitive or easily irritated (DSEI) eyes.

MATERIALS AND METHODS
This was a two-week, daily wear, randomised, contralateral study conducted by 21 investigators in four European countries (UK, Austria, Germany and Sweden), North America (US and Canada) and Malaysia. Subjects wore the test lens (new 1-Day Acuvue) in one eye and one of three other daily disposable lenses in the other eye. Different sites used a different lens as the control. The control lenses were Biomedics 1-day (Ocular Sciences), SofLens One Day (Bausch & Lomb) or Focus Dailies (Ciba Vision). The identity of the sponsoring company was masked to subjects. The lens parameters used in the study are listed in Table 1.
Current wearers of any Johnson & Johnson Vision Care products were not eligible. Subjects were excluded from the study if they were amblyopic, showed evidence of lid or conjunctival abnormality or infection, or had clinically significant slit-lamp findings. Those suffering from any active ocular disease or systemic condition contraindicating lens wear were also ineligible.
There were three scheduled visits during the study: a screening and trial fitting visit; lens issue; and a follow-up visit.

Initial visit
At the initial visit, subjects were questioned about their previous contact lens-wearing experience and asked to state their level of agreement with the statement: 'I feel my eyes are dry, sensitive or easily irritated'. Baseline measurements were taken and subjects were then fitted with 1-Day Acuvue in one eye and a control lens in the other eye. Test and control lenses for each subject were randomly assigned. If both the control and test lenses were successful then the subject was enrolled. If either lens were unsuccessful, the subject was not enrolled and was not dispensed lenses.

Lens issue
Once enrolled, subjects were issued with sufficient lenses to wear until the follow-up visit. It was stressed that a new lens should be inserted each day and that no care products, including saline, were to be used.
All subjects were requested to wear the study lenses for at least eight hours a day, five days per week, and to complete at least 10 days of lens wear prior to the follow-up visit. They were also asked to wear the lenses for at least two hours prior to this visit.

Follow-up visit
At the follow-up visit, baseline measurements were repeated and subjective comfort recorded on a 0-10 scale. Those showing unacceptable comfort, fit or slit-lamp findings were deemed unsuccessful. Subjects completed a questionnaire to rate the two lens types for overall preference and preference in relation to various attributes. At the end of the study, investigators were asked how they would position the test lens in their practice based on their experiences.

Data analysis
Differences between test and control lenses were compared at the baseline/issue visit and at the follow-up visit. The Wilcoxon's signed ranks test for matched pairs was applied as all data were found to be non-normal. The nominal questionnaire data were evaluated using the Pearson chi-square test. A P-value