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Solutions for contact lenses are considered incompatible if
the use irritates the eyes or discolors the lenses. Also when
solutions
that are to be used together, if not used in that same manner
may harm lenses or eyes. Different types of solutions are required
for different types of contact lenses and it is vitally important
to use only those solutions recommended for your specific type
of lens. Gas permeable lenses require special cleaners, soaking
and wetting solutions. Soft lenses also require many solutions
like daily cleaners, disinfecting solutions like hydrogen peroxide,
enzyme cleaners, rinsing and storing solutions. Generally soft
contact lenses are more prone to damage due to incompatibilities
but problems can also occur with gas permeable contacts.
Multipurpose solutions
Multipurpose solutions and MPD’s contain all ingredients
necessary for cleaning, disinfecting and storing in a single bottle.
They also enhance wetting and protein removal. They are designed
to promote better patient compliance but some people shortcut
the directions and also do not rinse their cases properly and
change the solutions nightly.
The solution becomes less effective after the first use, therefore
patients who fail to change their solutions or who merely top
off the solution remaining in the case may not achieve adequate
disinfection. Also, while topping off, some patients immerse the
tip of the solution bottle into the old solution that remains
in the lens case. This can contaminate the solution in the bottle.
As they squeeze additional solution into the case and then release
the tension, old solution is suctioned back into the container.
This can transfer bacteria and other material into the bottle
of cleaning solution.
Some patients do not understand the difference between saline
solution and multipurpose solution and purchase saline solution
as it is cheaper. Saline solution supports microbial growth and
no disinfection occurs. In addition, many patients stop using
solutions that were recommended by their practitioners and buy
generic solutions or whatever is on sale. Switching care systems,
mixing multipurpose solutions can lead to lens discoloration,
clouding and more adverse reactions like toxic red eye. Frequent
replacement lenses have less adverse reactions caused by improper
use of multipurpose solutions.
Solution Incompatibilities in Soft Lenses
Products from different manufacturers with different preservatives
and active ingredients interact with one another and many contact
lens solution incompatibilities are found to occur. All eye specialists
are familiar with the scope for damage to the lenses or the eyes
and the symptoms when contact lens care solutions are used inappropriately.
Since the manufacturer of one company does not test how their
product reacts when mixed with products of other manufacturers,
it is difficult to document which solutions are incompatible.
However, there are some reactions that are documented. In case
of soft lenses, if the user changes from one cold disinfecting
solution to another without changing the lenses then precipitates
can form on the lens matrix. If a tablet neutralizer with catalase
is used in a case containing a catalytic disc, then the disc will
become gummy and there will be incomplete neutralization. If the
contents of the neutralizer or case becomes foamy and overflows,
the surfactant cleaner then has not been thoroughly rinsed from
the lenses before disinfection.
If hydrogen peroxide system containing Ultracare is used for
disinfecting any sandwich technology lens, then bubbles will form
on the inner layers of the laminates. When silicone hydrogel lenses
are disinfected with Ultracare, “sag depth” may occur.
If ReNu Multiplus is used with Pure Vision hydrogel lenses there
may be complications. When soft lenses are soaked overnight in
a surfactant cleaner in an attempt to remove heavy deposits, it
will be difficult to completely rinse out the cleaner and sometimes
some cleaners distort the shape of the lens due to the presence
of isopropyl alcohol in the solution.
Rigid Gas Permeable Solution Incompatibilities
In rigid gas permeable lenses, solution incompatibilities occur
when patients mix solutions from various manufacturers or if non
appropriate cleaning agents like dishwashing liquids, baby shampoo
or toothpaste are used to clean lenses. In these cases there is
drying of lenses, itching, burning, hazy vision, heightened lens
awareness and surface deposits and some patients experience injection
in the conjunctiva, mild epithelial edema, SPK, hydrophopic surface
spotting.
There are few incompatibilities which are felt with RGP solutions
like when borate buffered solutions are used in conjunction
with those containing polyvinyl alcohol then a sticky gel forms
on the lenses. When generic peroxide is used then lens surface
becomes soft and there is resultant scratching, scoring and
scuffing. If chlorhexide preserved solutions are used with lenses
that contain styrene then there will be clouding on the surface
of the lens.
Maintaining a successful contact lens care system is largely
dependent on patient compliance. The users of contact lenses can
avoid problems by purchasing only those solutions that have been
prescribed by the practitioner. Mixing or transferring solutions,
contaminating them, skipping nightly care routine will result
in complications. So patients should first be educated regarding
contact lens care system.
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