Evaluating the Success of Habitual Multifocal Wearers When Refit With a New Lens Design

Evaluating the Success of Habitual Multifocal Wearers When Refit With a New Lens Design

The objective of the study was to adapt existing multifocal soft lens wearers to a CONTROL lens for 2 weeks and then evaluate the success of switching them to the TEST lens, with a review after 2 weeks.

This was a prospective, crossover, bilateral daily wear, and subject masked dispensing study. The habitual contact lenses were not optimized. There was no randomization of the study lenses, participants wore the control lenses for the first wear period and the test for the second wear period. Participants wore each study lens for 3-7 days and then attend a prescription optimization visit. After this optimization visit, they wore each study lens for a 2-week period. During the 2-week wear period, participants recorded their subjective lens-wear experience remotely.

Inclusion Criteria:

1. Is at least 42 years of age and has full legal capacity to volunteer;

2. Has read and signed an information consent letter;

3. Self reports having a full eye examination in the previous two years;

4. Anticipates being able to wear the study lenses for at least 8 hours a day, 5 days a week;

5. Is willing and able to follow instructions and maintain the appointment schedule;

6. Habitually wears multifocal soft contact lenses, for the past 3 months minimum;

7. Has refractive astigmatism no higher than -0.75DC;

8. Is presbyopic and requires a reading addition of at least +0.75D and no more than

   +2.50D;

9. Can be fit and achieve binocular distance vision of at least 20/30 Snellen (or +0.20 logMAR) which participants also deem to be 'acceptable', with the available study lens parameters (powers +4.00 to -6.00DS)

Exclusion Criteria:

1. Is participating in any concurrent clinical or research study;
2. Has any known active* ocular disease and/or infection that contraindicates contact lens wear;
3. Has a systemic condition that in the opinion of the investigator may affect a study outcome variable;
4. Is using any systemic or topical medications that in the opinion of the investigator may affect contact lens wear or a study outcome variable;
5. Has known sensitivity to the diagnostic sodium fluorescein used in the study;
6. Self-reports as pregnant, lactating or planning a pregnancy at the time of enrolment;
7. Has undergone refractive error surgery or intraocular surgery.