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Thread: Subjective near refraction

  1. #1
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    Subjective near refraction

    Greetings,

    When determining a near refraction, addition power, what is the most common method?

    Using the phoropter and near-target (on the push-up rule on the phoropter head) approach

    OR

    trial frame/lenses with the patient holding a reading card or similar material?

    OR

    ???

    Regards Scott
    Last edited by Scott Fisher; 08-11-2003 at 01:33 AM.

  2. #2
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    Skip it all consult Stimson, Drew or Copeland, find out how old the patient is and how tall he is . Bifocal determined by age alone, and can get by with less if tall (long arms). Have watched results of refractionists for 40+ years and those who go by age alone have fewer complaints than those who try to examine for same. Give some concideration to patient's activities (watchmakers need more plus) but don't bother to examine for near unless special activities involved.

    Chip

    Yes, I expect to hear contrary opinions on this.

  3. #3
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    I (half-heartedly ;) ) agree................

  4. #4
    Master OptiBoarder Jeff Trail's Avatar
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    Scott,


    It is going to depend on who is doing the refracting :) .. if it is an ophthalmologist than Chip's method is going to be common..if it is an Optometrist than it is more often than not by phoropter.. and broken down in most of the chains it is majority of phoropter..and in private practice a mix of phoropter and trial frame..
    When I had two stores I had an OD come to one and an MD to the other, I refracted under both of them.. one we had plus lanes the other minus (majority of MD's refract in plus cyl.) .. I used the phoropter for the total refraction and than once done popped the chair up swung out the arm and had them hold a page sized card where they read normally.. times I tweaked the add to fit the comfort zone of each person.
    With Chips version you use the formula but it means everyone is at that certain point for that age range and it is trying to fit everyone into one set of numbers.. how we worked 40 years ago and how we work now is a lot different... just think about everyone reading this thread or board, we ALL are sitting at a computer and chances are that we are all set up at different ways..keyboard, screen etc., etc.. and I (when refracting) tried to match the refraction as close as possible to the needs of EACH person ..
    Chip says in his 40+ years it was the best he has seen, as a wholesaler (I sold my stores) I can tell you that broken down.. my Dr RX change in OD's on average is around 4%...in MD's on average it runs around 22% and I have one MD account it is 50%!!! (yikes).. oh it is not all due to addition problems.. but I still think using the formula may be a starting point but now a days it might be a little more complicated than that to meet all the needs..
    If you want the common answer majority is probably phoropter only... with phoropter/trial frame second, formula a distant third...mainly due to the numbers doing the refracting... their are less MD's refracting than OD's :) (that is if you can actually find an MD who is refracting and NOT having techs do it) :rolleyes"

    Jeff "changing with the times..we all have to sometime or another" Trail

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    Stopper & Optom(i find them great in refraction business) how you do ur near subjectie refraction

  6. #6
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    Start with the age normals that Chip suggests and modify from there. I give the patient something to read and ask them to hold it at a distance that they like to read. Keeping in mind there age and this distance I will use trial lenses over the current rx or a trial frame to determine the add. I very rarely use the phoropter for determining the near add. You should also try understand what the patient does every day and see how this will effect those tasks positively and negatively and address those situations as best as possible.

    The patient will also feel that you took the time to give them the best Rx for them. And you will have demonstrated how they will likely see with there new glasses

  7. #7
    Optimentor Diane's Avatar
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    Stopper said:
    Start with the age normals that Chip suggests and modify from there. I give the patient something to read and ask them to hold it at a distance that they like to read. Keeping in mind there age and this distance I will use trial lenses over the current rx or a trial frame to determine the add. I very rarely use the phoropter for determining the near add. You should also try understand what the patient does every day and see how this will effect those tasks positively and negatively and address those situations as best as possible.

    The patient will also feel that you took the time to give them the best Rx for them. And you will have demonstrated how they will likely see with there new glasses
    Stopper, Optom, NCOD and any other OD's out there.

    Got a question for you. Whether using the phoropter, or trial frames, realistically speaking the tilt of the lens in front of the eye is usually different than the final eyewear, not to mention vertex distance.... Using a trial lens over current glasses, if you're careful with the tilt, that issue may be improved, but then vertex of the trial lens is still a concern. My question is, do you compensate for all of these variables in the final result? As I begin to think more, I'm thinking of more questions, but will stop here...OC placement, combining trial lens over the eyewear, increasing thickness and possibly combining index, differences in curves of trial lenses, v/s correct curve lenses...do any of them have an impact on the patient's acceptance of the add power and what the eyewear will be used for?

    Diane
    Anything worth doing is worth doing well.

  8. #8
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    Diane,
    When refracting I always set the Phoropter with pantoscopic tilt to match the typical angle of most frames. Also with trial frames there is an an adjustment for the tilt and I usually have that crank to the max. Also the nose pad can be adjusted to help also. As far as all the other questions, I think most of those issues are insignificant. You are just trying to get the right power and most of the time the refining is done with +or- .25 or .50. Don't sweat the small stuff. Don't over think it:D

    Life is to short to drink cheap beer:cheers:

  9. #9
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    There are only two things to take into consideration: symptoms and previous Rx.

    If symptoms are present, modify accordingly; if not, don't.

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    I worked in a high volume Optometric practice for three years where the patient was dilated by the technician and basically all of our refractions were "wet". I would say that I averaged (roughly!) 11 patients a day for 5 days a week for 3 years. So, around 8500 patients. It was extremely rare to have a patient return for an add power problem. I would guess maybe 50 patients over 3 years and all we primarily used were patient history and a formula estimation.............My 2 cents........

  11. #11
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    Hello Diane,
    You have logic in your question,especially high power prescription from phoropter(over 4.00D)may need to be compensated for vertex distances and adjusted for pantoscopic angle in real eyewear.I am certain you know how to do it.
    Regards,
    Shabbir

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