Last week I had the benefit of attending a presentation on the most up to date recommendations for fitting the Synergeyes lenses.  For new ODs out there just getting familiar with this lens, I have been promised that this new method can simplify your fitting time to around 15 minutes on the initial day and 1 to 2 follow-up appointments.  Believe me, this is considerably less chair time than what it has been taking me to perfect the lenses since I began fitting larger numbers of patients in December.

Here's the idea:  Mid-K fitting.  To summarize the words of Dr. Beatty (who gave the presentation), "fit the RGP like a hard lens, and the soft skirt like a soft lens."  Makes so much sense...

1) Determine K's, then find the average K value (mid-K value).
I usually just use my autorefractor and average the K's from flat and steep.  Remember, in order for this lens to work you can't have more than 1 diopter of residual astigmatism, so K values and corneal cyl are really important to evaluate before even opening your trial set.  I was told that if the patient has less than 1 diopter of corneal cyl, you should add 0.50 D to your mid K value.

2) Use the Synergeyes conversion table to select the appropriate base curve for your Mid-K value.
Find your mid-K, go across the table to find the base curve in radians.  Remember, the Synergeyes lenses only come in a few base curves (7.9, 7.7, 7.5, 7.3).  Round your conversion value to the nearest available base curve.  Example: if your K value gave you 7.46, select the 7.5 base curve.

3) Insert the appropriate lenses on each eye, using the medium skirt curve.

NaFl staining should look like this, but it pretty much always does unless you are really off on base curve.

For first time wearers, it works best for you to insert the lens yourself.  I have found that fluorescein really doesn't tell you much on these lenses unless you are super flat or steep, so I would skip that step if you feel comfortable looking at RGPs with a slit lamp.  To save on time, have your tech insert the lenses for you.  You need to let the lenses settle at least 10 minutes before evaluating to truly judge the fit.

4) Over-refraction
All the fitting set lenses are a -3.00, so you have to over-refract to find the correct power to order.  Patient will tend to want to overminus you in this lens, so make sure you fog well, or do retinoscopy.  Your final lens should be within -0.50 to -1.50 more minus than the spherical spec Rx.  This is different from the original fitting recommendation, allowing more minus!  It has been recommended that you let your patient wear the trial frame of their Rx around the office before they leave so they can see what their distance and near vision will look like.

5) Slit Lamp Evaluation
Waiting that 10 minutes is going to help you evaluate the soft lens skirt to make sure it is not fitting too tightly.  Originally, the Synergeyes lenses were recommended to be fit with a steep skirt when comfort or vision problems arose, but we now know that movement of the lens between blinks is essential to fit and comfort.  If you have a medium skirt on the patient and you don't see movement with blink, then you need to order a flat skirt.  Changing the skirt should not influence the over-refraction.  I have seen patients come back a week after their initial lens was dispensed with a ring around the cornea from the skirt fitting too tight, so make sure the lens is moving!  It will only get tighter as it dries out during the day.

6) Duette Multifocal Add selection

Ghosting creates almost a "3D" view for near This is normal with this lens

For presbyopes, there are 2 add powers available: small and large.  The new method recommends starting with small adds in both eyes.  This is especially true for early presbyopes. If near or computer vision becomes an issue, try going to a large add on the non-dominant eye. I was told that a large add in both eyes is really reserved for late presbyopes.  I think this is different from original recommendations as well. Educate your patients to expect to have that "shadowing" or "3D ghosting" effect that so many multifocal wearers describe.  If you prepare them for it, they won't think of it as a problem inherent to a bad fit.

7) Insertion and removal
Check out the company's videos here
Always fill the bowl of the lens before inserting.
Best to insert the lens with your face parallel to the floor.
Remove the lens by pinching the soft skirt between your fingers below the center of the lens, and then lifting up and out to break suction
Use Biotrue or Aquify solutions.  Clearcare for heavy depositors.  See this post for more info.

Synergeyes Duette is a RGP in the center for great optics, surrounded by a silicone hydrogel skirt for comfort

You can probably tell from my previous posts (here, here, and here) that I have really been incorporating the new Synergeyes Duette lenses into my practice.  Unfortunately, they haven't always been the easiest lenses to fit.  I was seeing patients back 3 or 4 times (or more!) over a period of 2 months to get the vision and fit comfortable for some patients.  The lens would look great, I was following the fitting guide, but my patients were getting variable results.

Then came the break through.

If you are going to fit Synergeyes Duette lenses, don't follow the fitting guide.  At least, not the one they gave you initially.  I was told earlier this week that the fitting guides are being changed and redistributed, so if you have a trial set in your office this new information will be available soon.  The original fitting guide had you fitting lenses based on flat K, over refracting, and then maybe going to a steeper skirt curve if the distance vision still didn't seem sharp enough.  Sometimes it worked; sometimes it bombed.The new fitting technique is straight forward and makes a lot of sense.

Step 1:  Get the Patient's K readings and find the average K value.




You can use a topographer (left), your autorefractor, or a (gasp) keratometer for your K readings.  If you are fitting this lens, the cornea should be pretty regular, so using the autorefractor K's should be good enough in most cases.









Step 3: Round your Base Curve to the nearest available Synergeyes Base Curve (they only offer 7.90, 7.70, 7.30, and 7.10)

Step 4: Insert the trial lens in the Median Skirt curve and Over Refract -- make sure you are within +/-1.00D of the spherical glasses correction!  Remember, you need less than 0.75D of residual astigmatism (just like any other RGP) to make this lens work.  I have been told it can handle up to 4.00D of cyl, but I haven't tried that high.  If your over refraction isn't within that 1.00D target, your base curve probably needs to be adjusted.  Just SAMFAP to tell you which direction to go.

Step 5: Order.  You can still adjust skirt curve for comfort (steep and flat options are available).   And in the multifocal lens you can use a large (better for distance vision) or small (better for near vision) add zone to improve vision.  I will say that basically every lens that I put on a patient looks like a good fit, so using fluorescein hasn't been that helpful.  Judge going steeper or flatter based on patient complaints.  Also, there is very little movement of the lens if the fit is too steep, so make sure to check that out. Little tweaks from your original fit should be all that is needed!


I am just now incorporating this method into my office, but so far it seems to make a lot of sense!  Please post if you are having any problems or any advice for other ODs out there fitting this lens.  Overall my patients do really like the vision and comfort in this lens once we get the fit correct.  Hopefully with this new method, finding the right fit will be a lot less time consuming.