Synergeyes Duette Fitting Guide for the New OD

 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 2: Use a Diopter Conversion chart to match the K value to a Base Curve radius.

My Synergeyes representative tells me I will be getting one from their company with some sample pictures of ideal fits in the near future.

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.