Article Date: 5/1/2000

Daily Disposable Versus Two-Week Disposable Lenses

LENS COMPARISON

Daily Disposable Versus Two-Week Disposable Lenses

By Christine Sindt, OD
May 2000

This clinical study of patient preference pitted Focus Dailies single-use lenses against the leading two-week replacement lens.

Previous studies comparing daily disposable contact lens brands have shown a strong patient preference for Focus Dailies single-use contact lenses (CIBA Vision) over other single-use, daily disposable soft contact lenses. But what about the predicted patient preference for a one-day contact lens over a two-week replacement contact lens? International studies, predominantly in European countries, have shown that patients preferred a daily disposable contact lens to their previous lens modality. We wondered whether or not patients in North America would appreciate any differences in convenience, comfort and handling of a leading single-use contact lens versus the leading two-week replacement contact lens.

The purpose of this study was to evaluate the overall patient preference of Focus Dailies one day contact lenses as compared to two-week replacement Acuvue lenses (Vistakon).

Study Design

This was a prospective, open label study that involved 118 subjects from 10 investigative sites (one in Canada and nine geographically distributed throughout the United States). Each site enrolled currently successful daily wear contact lens wearers from their patient population. The subjects could not be wearing the Focus Dailies one day contact lens, or any contact lens manufactured by Vistakon.

Inclusion and Exclusion Criteria

INCLUSION CRITERIA

  • Have signed the Patient Informed Consent
  • Are successful daily wear contact lens wearers
  • Full time wearer (at least eight hours daily wearing time/five days a week)
  • Healthy and non-irritated anterior segment of the eye at the baseline examination
  • Vertex corrected spherical equivalent ametropia between -0.50D and -6.00D
  • Cylindrical ametropia < -0.75D
  • Corrected visual acuity of 20/30 or better in each eye
  • Available for the planned appointments throughout the study

EXCLUSION CRITERIA

  • Acute infection of the cornea or conjunctiva
  • Any tissue change or abnormality of the anterior segment of the eye which would affect the wearing of contact lenses
  • Acute or chronic inflammation of the anterior chamber
  • Insufficient lacrimation
  • Surgery to the cornea (e.g. PRK, RK)
  • Simultaneous participation in another clinical trial
  • Inability to comply with the protocol criteria
  • Any systemic disease or use of medications that may affect the eye or be exaggerated by wearing contact lenses
  • Any condition requiring ophthalmic medication
  • Active acute allergies/hay fever/GPC

After inclusion and exclusion criteria (see sidebar at right) were met, each subject was fit and same-day dispensed in a randomized fashion with the Focus Dailies lens in one eye, and the Acuvue lens in the fellow eye. Subjects were then given a two-week supply of Focus Dailies and instructed to wear a new lens every day, disposing of the it at the end of the day. The Acuvue lens was worn on a daily wear basis for two weeks. Patients cleaned and disinfected the Acuvue lens daily using their habitual lens care products. After two weeks, subjects returned for a final visit, and completed a forced choice questionnaire on their subjective evaluation of overall lens preference, overall comfort, initial comfort and overall ease of handling and convenience.

Previous and separate studies have shown that both Dailies and Acuvue two-week lenses provide good clinical performance regarding vision, fit, comfort and health. The clinical evaluations measured in this study were visual acuity, fit of lenses and biomicroscopic findings of bulbar redness, epithelial staining, striae, edema and any other abnormal finding.

Subjects

Some 93 females and 25 males, ranging in age from 11 to 57 years (averaging 31 years) participated, approximating a normal contact lens wearing population. The habitual contact lenses worn previous to the study ranged from two week to yearly replacement and can be seen in Figure 1. The habitual lens care systems used previously and throughout the study were predominantly multi-purpose.


Figure. 1: Replacement schedule of habitual lenses

Materials

The lenses, and their parameters, used in this consumer preference study are outlined in Table 1.

TABLE 1 Study Lenses
PARAMETER  TEST  CONTROL
Name Focus  Dailies Acuvue
Material nelfilcon A etafilcon A
Water percent 69  58
Base Curve 8.6  8.4, 8.8, 9.3
Center Thickness 0.10 mm (-3.00) 0.07 mm (-3.00)
Diameter 13.8 14.0, 14.4
Rx range for test -0.50 to -6.00 -0.50 to -6.00

Results

Figures 2-6 show results from the patient questionnaire. In terms of overall lens preference, 84 percent of the patients preferred the Focus Dailies over the Acuvue lens. Some 90 percent preferred Dailies for convenience, 79 percent for initial comfort, 82 percent for overall comfort and 74 percent for ease of handling. These results indicate that patients generally prefer the Focus Dailies lens in a daily disposable modality. Five out of six patients preferred Dailies to Acuvue even though over 75 percent were already accustomed to a frequent replacement modality (50 percent two weeks, 28 percent one month).

We recognize that this study compares two different regimens of replacement schedules, and that there are obvious advantages and disadvantages to each regimen. However, in this study comparing the two different regimens, there was a clear patient overall preference for the daily disposable lens modality.

In addition, no clinically or statistically significant differences existed between the two lenses for the clinical evaluations of bulbar redness, epithelial staining, striae or edema. There was no degradation of visual acuity from habitual lenses. No adverse events occurred during this study, and no subjects were discontinued for any reason. One patient returned for an unscheduled visit for a refit of the Acuvue lens to a different base curve.

Discussion

Frequent replacement of contact lenses, especially daily disposable, benefits both patients and eye care professionals. As previous studies have shown, patients appreciate better comfort, vision, ocular health and the overall convenience of less lens care. Practitioners appreciate fewer clinical complications and the overall satisfaction of contact lens wearers. The results in this study are similar in that no clinical complications were noted with either the Focus Dailies or the two-week Acuvue.

This study supports the presumption that daily disposable lenses in general offer convenience and comfort advantages to patients. In a side-by-side comparison with no previous experience with either product, patients concluded that the Focus Dailies lens was more comfortable overall, more convenient and easier to handle than the two-week Acuvue lens, a lens widely regarded for its comfort and convenience. Contact lens practitioners seeking comfort and convenience for their patients can use the results of this study to assist in patient management decisions. 

References are available upon request to the editors at Contact Lens Spectrum. To receive references via fax, call (800) 239-4684 and request document #60. (Be sure to have a fax number ready.)

Acknowledgements:

Co-authors: Randy L. Andregg, OD; Carolee R. Boyd, OD; Carol Deitz-Bertke, OD; Roy A. Kline, OD; and Brenda Weirich, OD

Participating Investigators: Wiley Curtis, OD; Nelson Murata, OD; Dan Robinson, OD; Michael Rotholz, OD; Paul Sorg; and Casey Tepperman, OD

Dr. Sindt is an Assistant Professor of Clinical Ophthalmology and Director of the Optometric/Contact Lens Services at the University of Iowa Hospitals and Clinics. She also sees patients in the UI Center for Macular Degeneration's Low Vision Service.


  Figure. 2: Percent subject overall lens preference.


Figure. 3: Percent subject lens preference for overall comfort.


Figure. 4: Percent subject lens preference for ease of handling.


Figure. 5: Percent subject lens preference for convenience.


Figure. 6: Percent subject preference for initial comfort.


Contact Lens Spectrum, Issue: May 2000