Air Optix Multifocal Fitting Guide -- do you really know the recommendations for best fit?
air optix multifocal fitting guide 8:47 PM
Fitting contact lenses can be such a routine after awhile, it's easy to forget about that little fitting guide the reps give you the first time a lens launches. We all know how to do it any way, right? Pick the right lens, the right add, and over refract. But with the new launch of Ciba's Dailies Aqua Comfort Plus Multifocal which is utilizing the exact same multifocal design as their original monthly Air Optix Multifocal lens, let's take another look at the fitting guide because what's inside may surprise you.
Here's the link to Ciba's Version
1) Start with your vertexed distance power and select your add based on this traditional scale. Start with the same add in both eyes.
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2) Over-refract at a distance with +0.25/-0.25 trial lenses or flippers. Make sure both eyes are open (do NOT do monocular over-refractions). Change power of lens accordingly -- try to push as much plus as possible at this stage without hurting distance vision.
STOP. If vision is acceptable distance and near with binocular vision and good lighting, dispense the trial lenses.
Having trouble with distance or near? Time to take advantage of ocular dominance. To determine dominance I like to use the +2.00 blur out method. Hold up +2.00 or +1.50 over each eye at a distance binocularly. Which option looks better? The eye that can't take the plus is your dominant eye.
If Issues with Distance:
If over-refraction can't solve distance complaints, it is time to use that dominant eye to our advantage and split adds. This may seem obvious, but check out that last line of the table. For Hi adds, you should drop to medium add power on the NON-dominant eye. Yes, you read that right. Shocked? I was. I can't say it makes sense, but apparently it should work.
If Issues with Near:
1) Add +0.50 to the Non-Dominant eye. That's right, before you start messing with add, try pushing a little more plus. At this point, you are committing to sacrificing a little distance in the name of near.
If you still can't get good enough near vision, then from here, split the add as described:
2) Split the Add:
Yes, again the Hi add power is counter-intuitive. You drop the non-dominant add to medium.
I haven't been able to get a good scientific explanation as to why this strange add adjustment on the Hi adds works, but the blended zones of multifocal contact lenses can yield crazy results. I am guessing if there are vision issues, then we are assuming the eye is not being able to take advantage of a certain add power's blend, so we are trying to utilize a different power blend to increase visual function. As we all know, the power of the multifocal contact lens is just a starting place, and many times the final contact lens Rx doesn't match that well with a person's glasses prescription because multifocal contact lenses are so variable in the vision they provide. It is all about how a patient's eye and brain can utilize the blended zone information it is being given. That's why vision may take a week or two to even reach it's true potential; the eye and brain have to learn how to interpret the lens.
So if you are wanting to achieve even better multifocal results, try revisiting the fitting guides of your lenses. You may be surprised by the suggestions inside!
