Practitioners are increasingly prescribing silicone hydrogel contact
lenses for daily and flexible wear schedules as they consider
silicone hydrogels to be the lenses of choice for more and more
patients. In addition to new fits, practitioners are refitting many
patients who wear traditional hydrogels for daily and flexible wear
into silicone hydrogels. Currently, silicone hydrogel lenses account
for more than 30 percent and 25 percent of lenses prescribed for new
daily wear fits in the United States and Canada, respectively.
cases, patients who've been upgraded into silicone hydrogel lenses
will continue to use their existing lens care products. However,
recent evidence suggests that certain multipurpose solutions can
interact with various silicone hydrogel lens materials and result in
varying levels of corneal staining. We undertook a study to explore
patient experience and ocular response to use of silicone hydrogels
with CIBA Vision's Aquify Multi-Purpose Solution (Aquify MPS), which
is indicated for use with silicone hydrogel lens materials.
Need for Solution Compatibility
who continue to use their existing lens care solution with their
silicone hydrogel lenses and who develop associated corneal staining
may be at risk for more serious consequences in the long term.
Specifically, a recent study examined solution toxicity, defined as
diffuse punctate staining in at least four out of five areas of the
cornea. In this study, patients who experienced solution toxicity
were more likely to experience an infiltrative event and to report
lower subjective comfort. Thus an incompatible lens care solution
can potentially compromise the success of patients who wear silicone
MPS is compatible with all soft contact lenses including silicone
hydrogels. It's the only multipurpose solution the FDA has cleared
for use with silicone hydrogel lenses that offers the flexibility of
two disinfection options: in addition to the traditional no-rub,
four-hour-to-overnight soak option, patients can perform a 10-second
rub with a five-minute soak. With reported high disinfection
efficacy and minimal corneal staining, its formulation is designed
to address contact lens discomfort and lens dryness. Aquify MPS
contains dexpanthenol, a moisturizer found in dry eye and
wound-healing products which, when combined with the humectant
sorbitol, has been shown to increase the water retention of
The ocular health benefits of high oxygen transmissibility offered
by silicone hydrogel contact lenses are well documented for both
daily and continuous overnight wear. Despite this, it's important
that patients don't become complacent with lens care. Even with
silicone hydrogel lenses, they must take care to minimize the risk
of microbial contamination of lenses, which may lead to infection.
five-minute cleaning and disinfection option, we believe Aquify MPS
offers an easy and convenient method for patients to effectively
disinfect their lenses, thereby helping to promote compliance.
Study Design and Methods
clinical study set out to evaluate and compare subjective ratings of
comfort and convenience as well as to evaluate compliance for
silicone hydrogel wearers when switched from their habitual lens
care brand to Aquify MPS. We conducted the study at one clinical
site. To be included in the study, subjects had to be adapted
silicone hydrogel wearers who wore lenses at least five days per
week, at least eight hours per day and who slept in lenses no more
than three nights per week; they had to be multipurpose solution
users but couldn't currently be using Aquify MPS. Subjects were
masked to the sponsor of the study. All subjects signed a written
informed consent prior to enrollment. IRB approval was not required
because all study products were marketed products used within the
indications for use.
baseline, subjects underwent an ocular evaluation and completed a
baseline questionnaire. The investigator then gave subjects Aquify
MPS to use for the two-week study period and instructed them to use
either the four-hour soak option or the five-minute soak with rub
option. Subjects received instructions on both options. During the
study, subjects wore their habitual silicone hydrogel contact lens
brand for daily wear only; or, for subjects wearing lenses
FDA-approved for extended wear and obtaining investigator approval,
they could wear the lenses overnight for up to three nights per week
(consecutively or not).
the study period, subjects completed diaries with information about
their lens wear and lens care. When subjects returned at two weeks,
they were re-examined and completed follow-up questionnaires. We
compared their subjective evaluations of the performance of Aquify
MPS and their habitual lens care system. We also evaluated
compliance with lens care regimens using the completed diaries.
Sixty-three adapted silicone hydrogel lens wearers (15 O2
Optix [CIBA], 16 Night & Day [CIBA], 16 Acuvue Advance [Vistakon]
and 16 PureVision [Bausch & Lomb]) completed the study. Table 1
shows subjects' habitual lens care brands.
TABLE 1 Lens Care Brands of Study Subjects
initial visit, 29 subjects (46 percent) indicated that they
occasionally or frequently remove their lenses for a quick clean and
then immediately reapply them. Also, 75 percent of subjects, all
using traditional multipurpose solutions with the typical four- or
six-hour disinfection cycles, expressed interest in being able to
clean and disinfect their lenses faster than their current lens care
Evaluation of Key Features
Preference Subjects compared Aquify MPS to their
habitual lens care system for product attributes relating to comfort
and convenience. Subjects could answer that the test lens care
product was much better, a little better, the same as, a little
worse than or a lot worse than their habitual lens care product.
Study subjects rated Aquify MPS superior to their habitual solutions
for attributes relating to subjective comfort, convenience,
flexibility and moisturizing effects. There were no attributes for
which they found their habitual products to be better than Aquify
MPS. Figures 1 and 2 show the key findings.
Figure 1. More study subjects preferred Aquify to their
habitual brand for subjective comfort.
Figure 2. More study subjects preferred Aquify MPS to
their habitual lens care for convenience.
Complaints An evaluation of subject reports of
problems experienced while wearing contact lenses revealed that a
significant number of subjects experienced less redness (p=0.000,
Wilcoxon signed rank sum test) and less blurry or hazy vision
(p=0.001, Wilcoxon signed rank sum test) after using Aquify MPS as
compared to when they used their habitual lens care system. Other
problems such as lens awareness, eyes watering, eyes burning or
stinging and eye irritation weren't significantly different.
Evaluation of compliance with lens care revealed that 93 percent of
subjects' diary entries indicated that they used Aquify MPS as
directed. When asked which lens care product best allowed them to
care for their lenses the way they were supposed to, twice as many
subjects selected Aquify MPS as compared to their habitual lens care
(p=0.03, McNemar test).
The investigator graded corneal staining at baseline and at follow
up using a scale from 0 to 4 where 0=none, 1=very slight, 2=slight,
3=moderate and 4=severe. At baseline and at follow up, corneal
staining was minimal. At follow up, after using Aquify MPS, 47
percent of eyes exhibited no corneal staining and the mean staining
grade was 0.4 �0.6.
Aquify vs. Leading Habitual Study Solution
Express (Alcon) users represented the largest habitual lens care
group in the study (48 of the 63 subjects in this trial) and
comprised a sample size large enough for statistical analyses. We
performed a post-hoc analysis of the results from this group.
subjects' comparisons of Aquify MPS to Opti-Free Express, Aquify MPS
out-performed Opti-Free Express on several key attributes including
comfort, clean-feeling lenses, flexibility and convenience. Opti-Free
Express didn't significantly outperform Aquify MPS on any variable
we evaluated. Figures 3 and 4 present results of this comparison.
Although a placebo effect can't be ruled out, we believe these data
Figure 3. Opti-Free Express didn't perform significantly
better than Aquify MPS in any of 11 subjective comfort
Figure 4. More study subjects preferred the flexibility
of Aquify MPS over Opti-Free Express.
wear and flexible overnight wear of silicone hydrogel lenses,
contact lens wearers are adapting their lens cleaning and
disinfection to suit their wearing patterns. An interesting finding
from our study is that 46 percent of the subjects revealed at
baseline that they remove their lenses for a quick clean during the
day, although all of them used lens care products that required a
four- or six-hour soak. In this study sample, patients achieved a
high rate of lens care compliance (93 percent) when using Aquify
MPS, which provides an option for rapid cleaning and disinfection.
article highlighted the importance of lens disinfection and
recommends: Hygiene and general lens care should also be emphasized
at every visit. If a contact lens is out of the eye for any time, it
should be disinfected before replacement in the eye, or a new lens
should be used. For those who routinely remove their lenses for a
quick clean, Aquify MPS is the only solution indicated for use with
silicone hydrogel lenses that can provide disinfection, with a rub,
in five minutes.
today's market, in addition to providing options for rapid cleaning
and disinfection, the performance of lens care solutions with
silicone hydrogels is of key importance. Zhang et al (2006) found
Aquify MPS less likely than other MPS solutions, including Opti-Free
Express, to stimulate corneal inflammatory mediators (cytokines)
when used with lotrafilcon B lenses. Cytokines play a major role in
a variety of immunological, inflammatory and infectious diseases and
their increase may contribute to contact lens-associated adverse
MPS contains moisturizing ingredients that provide comfort and
compatibility with silicone hydrogel contact lenses. In our study,
Aquify MPS performed better for silicone hydrogel lens wearers on a
daily or flexible overnight wear schedule compared to habitual lens
care and also compared to Opti-Free Express. We found that Aquify
MPS delivered significant improvements in comfort and convenience
over habitual lens care and over Opti-Free Express.
believe the choice of a traditional four-hour soak or a five-minute
soak with rub for disinfection provides convenience that complements
the flexible wear patterns and emerging habits of many of today's
silicone hydrogel contact lens wearers. We also believe the ability
to effectively disinfect lenses in five minutes (with rub) helps to
promote lens care compliance, an important part of healthy contact