I have had several optimized rx's in reasonably high myopic powers that pt's have had trouble adapting to. One thing I've noticed is the actual power is weaker than the prescribed rx which the pt's have complained about their vision being fuzzy? I ended up having the lenses remade without optimizing and they were fine? I'm referring to wrap frames as well as regular dress eyewear. I have seen some rx's up to .50 weaker than actual rx? Just curious if anyone else has had issues.
This is a tough situation to tease out the offending culprits. Try trial-framing the DV Rx, adjust/note to vertex, and use flippers to determine if the RX is spot on. Review the compensations in light of this.
I really have had not compensated failures when orig Rx is appropriate for client's expectations and/or utility.
B
Let me guess that you are using a Shamir product? Add back the -.50 to the distance and it will fix the compensation issue. I have also added 0.25 BO to turn it off and that helps as well; you could do what I did and not use Shamir compensation?Originally Posted by dash1
I have not used Shamir since September and most of my issues also vanished!
PS- I am hostile because when I shoed this to Shamir, they told me I was a complainer and they did thousands per day with no problem! I said that was not the issue and they called me an ***-hole by the lead US technical guy. This did not make me happy and the rep was in a few days ago to get his dose of reality. I also save $$25 per job after the bogus rebate of $15.
I have had this problem with shamir but also with wrap rx's in non digital as well as digital designs . I had a guy rx -4.25 with a little cyl in both eyes, they had to put his rx on a 6 base for fit, the lab optimized the rx ,without me asking for it, the sph was reading -3.87 with a little more cyl? Had another was an rx -3.25 sph and -3.00 sph in a rec spec, the lab gave me -3.00 w/cyl and -2.75 w/ a little cyl? I don't know if this is normal compensation? I didn't give any POW measurements, after having the scripts remade without compensation pt's were fine. I haven't had any trouble with hyperopic rx's. These are just a few of the issues I've had. Do they always assume to reduce the rx? It sometimes seems like the rx's that would benefit from optimized designs don't, even when POW is used?? It could very well be us not taking them right but I don't know.
Last edited by dash1; 04-18-2012 at 08:12 PM. Reason: adding
absolutely we have had that issue. on wrap around maui jims as well as personalized/optimized rxs (progressives and sv). The distance RX would read about .5 weaker and each time the client complained of blurred distance vision. Add back the -.50 and all is well.
Clearly an issue of the practical application of a theory not working. I do not buy this compensation business with "optimizing". The same supplier offers plenty of lens designs that don't include this optimizing and we just don't have the same problems. Jus' sayin'.
What are flippers?
Maui is Shamir, so is Kaenon, Oakley and ? Costa and that is why the same problems exist. I just had an the same issue with optics by Shamir with my Internet partner, who is also a fishing guide. He hates the vision out of the Oakley, Maui Jim and the Kaenon while loving the one no name digital we made. He is only a +1.50 OU 2.25 add and the compensation drives him crazy. He also got a cheap pair off the internet that made him sick, so he is sensitive to the lens but it is a compensation issue!!!!
PS-Poly does not help the cause!
thanks
Welcome to Optiboard Dash1! You don't specify if the issue is visual acuity or "comfort"...
I see a couple of causes for this. One is Lenticular Astigmatism. When a large portion of the astigmatism is in the lens and not the cornea these patients have a tendency to dislike the stronger and custom compensated lenses. A cheaper (less optimized) Free-form usually solves the issue. You can determine this by comparing the K readings to the subject Refraction, and the Auto refection. If the K readings vary less than the subjective, you may have lenticular astigmatism.
The second I see is in the refraction. When a patients is on the border between two RX's, the Dr will often choose the weaker one. The lens weakens it more, and they are pushed too far. I recommend using the higher power if the lens will be compensated, lower if its not, or use .12ths as an alternative.
The third issue is design or pattern issues. All traditional lenses are an hourglass design, but Free-form can offer a multitude of patterns or shapes. The Auto II has enormous distance, but the reading is narrower than the Comfort. If your patient is a heavy reader they won't like the Auto II. We have to know each lens, where its weak and strong, and match that to our patients lifestyle more than ever. Free-form offers great variety but we have not fully adapted to that.
The fourth issue is what Barry calls Geometric distortions. When we move the add from front to back we are moving it from the steepest curve of the lens to the flattest. As well the distance usually steepens in reverse. Not bad per say, just different. Everything will move and feel different in a free-form lens from a grinder. If the patient is not informed of this at dispense, they will not like how it feels at first. Its disconcerting. But if they are informed they will adapt quickly.
You don't mention what their DVA acuity was with the new lenses, its crucial for trouble shooting issues. You can compare thier DVA with their subjective refraction, if its lower it could be a “too much compensation” issue. If it’s not, it’s one of the 4 above. Good trouble shooting will narrow it down quickly.
Last edited by sharpstick777; 04-19-2012 at 11:59 AM. Reason: damn I can't spell anymore
WOW! +1000 I really found this informative!
B
Good stuff. Makes me realize that there's a lot I don't know that I don't know.
Thanks Barry
Fezz, you are way too funny. Flippers are the best trouble shooting tool an Optician can have if they are used correctly.
Flippers are just an extension of the metric refractive process, done with "normal" size pupils, and "in situ" with meniscus lenses and known POW values.
B
Do you have a cite for this? It wouldn't be a problem for me to take k readings on all of my astigmats, but I don't understand how this relates to reducing marginal astigmatism and power error.
Prescribing is both science and art.The second I see is in the refraction. When a patients is on the border between two RX's, the Dr will often choose the weaker one. The lens weakens it more, and they are pushed too far. I recommend using the higher power if the lens will be compensated, lower if its not, or use .12ths as an alternative.
Traditional PALs can have a variety of shapes also.The third issue is design or pattern issues. All traditional lenses are an hourglass design, but Free-form can offer a multitude of patterns or shapes.
I suspect that when PALs are designed, and the data from the blind and double blind clinical tests are evaluated, and you're where you want to be functionality wise for the fundamental PAL design, you would not want to deviate from that design. In other words, the PAL designer chooses a specific 'flavor' of PAL design across a field of base curves and Add powers- one of the objectives of advanced optimizations is to try to keep the PAL design as close as possible to the intended design, regardless of the Rx, something that can not be done with semi-finished PALs.
In my personal trials (-3.00 -1.75 x 90 add 2.25 avid reader), the Auto 2 fixed 18 at 20 high was the clear winner at near compared to the Hoya, Zeiss, and Essilor optimized PALs. The others were not bad lenses, they were not the best for my Rx, pupil diameter, and visual needs.The Auto II has enormous distance, but the reading is narrower than the Comfort. If your patient is a heavy reader they won't like the Auto II.
Science is a way of trying not to fool yourself. - Richard P. Feynman
Experience is the hardest teacher. She gives the test before the lesson.
This thread gives me a headache, since the poster did not give enough info for an educated guess the alternative was provided darts thrown in a dark room.
Sharpstick, you should shoot the person that gave you those "facts"
Barry, *-1,000" for agreeing with that.
gmc, scrub your brain off real quick before that stuff sticks and dries..
Robert Martellaro, a bow and a tip of the hat to you.
Not real sure how much more info you would need to make a comment? I have read what I posted again and the question seems straight forward to me. Maybe you are reading too much into it?? I've had several people read and they seem to understand what I was asking. The main point of the question is anyone having trouble with optimized RX's in high myopic powers? I didn't give specific accounts because I didn't feel they were needed to answer that question. I am basically trying to find out if anyone else is having my same problem and what are their thoughts? Sorry you are are getting a headache, might need some computer pals??:)
shheeeesh. I don't like rx--ing the wraps any more. Way back when we used to edge and mount the most basic lenses in wrap arounds occasionally (before the digital optimized era), as we had a master lab tech. He "convinced" sola vips and flat base sv hi index lenses to pop into oakleys etc.. we had fewer issues than with todays factory made premium products from the big guys. On a side bar - I would swear I had fewer progressive non adapts in the pre-digital era. Ok, maybe not in a court room under oath. But it feels like it. Kind of. Meh.
Flippers are great!!
Time will tell if I deserve to off in the corner, and put on the dunce cap. If I should....I will.
My hat is always tipped to Robert...
B
What the Heck Fezz ?? Get with the program. You need to update to the new Free Form flippers
90% of everything is crap...except for crap, because crap is 100% crap
Ok........you asked for it!
Last edited by Fezz; 04-20-2012 at 03:01 PM. Reason: Try to erase the mental image of me wearing these!!!
Wow Fezz, you've got some set of enhanced flippers there !!!!!!!!!!!!!!!!!
90% of everything is crap...except for crap, because crap is 100% crap
Love the Free Form Flippers!
One thing to add. Dr.'s rx is only accurate at the vertex distance it was measured. The Free Form compensated Rx is generally compensated due to the difference between default measures and those the optician measures for the frame, however, if Dr. was not measuring the patient's Rx at the default distance of the Free Form manufacturer, the whole equation is off.
I wonder if part of the original problem is doctor taking high Rx measures with the patient's eyes too close to the phoropter, and then not trial framing to confirm accuracy. It is just one more thing to troublshoot.
Renee Kathleen Jacobs O.D., M.A.
Director Practice Management Depot
www.PracticeManagementDepot.com
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