> Hello pclar,
> Thank you for that story and explanations, it makes things clear now.
> But I would also like to know, howcome some of the ophthalmologists
> and the optometrists sometimes turn against each other and have fights
> and things? Why did that start?

> The chiropractors haven't
> changed as much.

> Dear Serious Reader,
> Please try to ignore the non-scientific comments of a
> layman foul-mouthed jerk, Neil Brooks, who has no medical
> training, and no clue about these scientific
> discussions. He is just a troll here on
> sci.med.vision.
> Here is the paper that Dr. Harris was reviewing.
> Keep an open mind.
> We are SERIOUS about preventing or avoiding ENTRY
> into a negative refractive STATE. All Brooks wishes
> to do is to ATTACK anyone who reviews
> these scientific issues -- for your interest.
> Best,
> Otis
> +++++++++++++
> Back to Bifocals for Young Esophoric Myopes?
> Robert Sanet, O.D., F.C.O.V.D.
> The following is an abstract of an article recently published in the
> Journal of the American Optometric Association by Fulk and Cyert:
> A short-term pilot study reexamines the utility of bifocals in slowing
> myopia progression in children with near-point esophoria. Subjects
> were 28 children (girls < 13 years old, boys < 14) with myopia
> exceeding 0.50 D in both eyes and near-point esophoria. Fourteen were
> given single-vision lenses, while 14 received bifocals with a +1.25 D
> add in a flat-top segment 28 mm wide.
> The bifocal wearers demonstrated myopia progression at an annual rate
> of 0.39 D/yr. over 18 months, compared to the 0.57 D/yr. rate of
> single-vision wearers. Even more significant was the difference in the
> rate for the last 6 months of the study: 0.37 D/yr. vs. 0.8 D/yr.
> Apparently it takes about a year for the effect of the bifocal wear to
> manifest itself. The children wearing bifocals could tell that their
> visual comfort was improved, and had little problem adapting to their
> glasses. At the end of the study 10 of the 14 chose to continue with
> the bifocals.
> The authors attribute these results to including only subjects with
> esophoria. Previous studies showing no significant differences between
> bifocal and single-vision lenses did not differentiate children with
> near-point esophoria and those with exophoria.
> Dr. Sanet states, "Although not stated anywhere in the article, this
> study is consistent with what would be expected from a behavioral
> perspective. Skeffington's syndromes of embeddedness did not include
> the 13B finding (near phoria through the subjective). However, it is
> my observation that incipient or early myopes measure esophoria on the
> 13B finding. As they become more embedded, they re-calibrate and
> reduce their esophoria and more into exophoria. Myopic exophores tend
> to be more embedded and less responsive to a lens prescription alone.
> These patients often need an Rx with yoked prisms combined with a
> program of optometric vision therapy in order to stabilize or reduce
> the rate of progression of their myopia."
> ==============
> On this same article Dr. Paul Harris felt that although the article
> showed some significant effect from the use of bifocals, the actual
> protocol used by the researchers reduced the effect. He wrote the
> following letter to the editor which has been accepted for publication
> and which should appear in the next issue of the Journal of the
> American Optometric Association.
> On Oct 3, 1:32 pm, "otisbr...[at]pa.net" <otisbr...[at]pa.net> wrote:
> > Dear Prevention-minded friends,
> > Subject: Why "weak" bifocal studies FAIL.
> > I have been asked to "explain" why some of
> > these bifocal studies fail. Rather than I explain
> > it -- why not listen and understand from a
> > second-opinion expert.
> > Otis
> > ============================
> > January 21, 1997
> > Journal, American Optometric Association
> > Dear Editor;
> > I eagerly turned to the article titled, "Can bifocals slow
> > myopia progression?" in the December issue (Vol 67, no 12, pp
> > 749-54) of the Journal of the American Optometric Association. As
> > the director of the Kraskin & Skeffington Institute, the
> > International Center for Education in Behavioral Optometry and the
> > founder of the Baltimore Academy for Behavioral Optometry, I teach
> > courses which cover the use of plus lenses in the management of
> > nearpoint vision problems. Although the article as published
> > showed some positive effect, its protocol was seriously flawed, as
> > have been nearly all research protocols of this type. I am
> > continually amazed at the resources that are consumed attempting
> > research where the protocol dooms the study to either failure or
> > minimal effect before the first patient has been seen.
> > A significant body of literature exists related to the use of
> > plus lenses. 1-5 Prescribing plus lenses to reduce a patient's
> > stress response to sustained near point activity must be done in
> > an individualized way. Studies by Darrell Boyd Harmon show that
> > statistically the most appropriate lens can be derived for a group
> > or cohort of people. 4 However, once derived for a group, due to
> > high individual variance and high sensitivity to slight changes,
> > the plus lens power derived from a group cannot be used for all of
> > the members.
> > The study conducted by Fulk and Cyert, as well as every study
> > that I am aware of relating to progressive myopia which looked at
> > the use of plus for near, has selected for its study a single lens
> > power to be used by all subjects. NOTE: Each study has used
> > different criteria to derive the lens power used, but all used the
> > same power on all members of a particular group. This is a
> > critical flaw that was carried through in the work by Fulk and
> > Cyert.
> > A critical aspect of understanding the use of plus lenses to
> > decrease the stress response of the patient at near is the fact
> > that there is a high degree of sensitivity to near point plus and
> > that each person is different. Dr. Darrell Boyd Harmon and Dr.
> > Robert Kraskin, in the development of their technique called
> > stress point retinoscopy, have provided a method of assessing the
> > degree of lens which will maximally decrease near point stress
> > responses. 5 Other physiological data, as well as a number of
> > articles, 2-3 clearly demonstrate that the amount of plus varies
> > on an individual basis, as well as validating the concept that too
> > much plus is just as bad or ineffective as too little.
> > The protocol of Fulk and Cyert led them to select +1.25 adds
> > for all members of the study, based on esophoria. This decision
> > must be called into question. It would be rather easy to set up a
> > protocol that could be made inter-tester reliable and that would
> > take into account the individual differences between members of
> > the study, yet have a uniform criteria upon which to provide each
> > subject with the lens which clearly reduces near point stress
> > response maximally. In other words, an algorithm could be
> > provided which would be the same for all members of a test group,
> > but which would yield different lens powers depending on the
> > variances and needs of each individual. In this way, the effects
> > of the lenses would be maximized and a significantly greater
> > positive effect of each lens would be obtained.
> > It is my hope that in the future academicians who have
> > procured funds for much needed research do not squander those
> > funds and the good will of the public by using protocols which
> > have little hope of showing effects. These flaws reveal
> > themselves most when research is being performed in a clinical
> > area in which significant expertise exists about which the
> > academicians are generally either uninformed or misinformed. It
> > seems that Fulk and Cyert are not in tune with how the majority of
> > those who work with patients to prevent progression of myopia go
> > about deriving the appropriate plus lens power for near.
> > What is needed are more open lines of communication between
> > those doing research in clinical areas and with the clinicians who
> > provide this type of care. Proposed protocols such as those used
> > by Fulk and Cyert could have been circulated among a panel of
> > clinicians in behavioral vision care and the points raised in this
> > letter would have easily surfaced before so much time, effort, and
> > energy were consumed.
> > To avoid these types of problems in the future, the Kraskin &
> > Skeffington Institute offers to assist anyone doing clinical
> > research relating to the use of lenses, prisms, and/or vision
> > therapy by reviewing, or have reviewed by appropriate experts, any
> > proposed research protocol for the purpose of making
> > recommendations to be communicated to the researcher. By acting
> > as a bridge between those who are best equipped to do research and
> > those equipped with the clinical expertise, better research should
> > result, as well as better communication between academia and
> > clinicians.
> > Sincerely,
> > Paul Harris, O.D., F.C.O.V.D., F.A.C.B.O.
> > Director of Education
> > References
> > 1. Birnbaum MH. Management of the low myopia pediatric patient,
> > J Am Optom Assoc 1979;50(11):
> > 2. Greenspan SB. A study of near point lenses: effects on body
> > posture and performance", OEPF, 1975
> > 3. Greenspan SB. Behavioral effect of children's nearpoint
> > lenses, J Am Optom Assoc 1975,46(10):
> > 4. Harmon Darrell Boyd. "Notes on a dynamic theory of vision"
> > OEPF
> > 5. Kraskin, Robert A., "Lens Power in Action", OEPF both volumes,
> > October 1981 - September 1983
> > =========
> > Note: On this same article Dr. Paul Harris felt that although the
> > article showed some significant effect from the use of bifocals,
> > the actual protocol used by the researchers reduced the effect.
> > He wrote the following letter to the editor which has been
> > accepted for publication and which should appear in the next issue
> > of the Journal of the American Optometric Association.

> Please try to ignore the non-scientific comments of a
> layman foul-mouthed jerk, Neil Brooks, who has no medical
> training, and no clue about these scientific
> discussions. He is just a troll here on
> sci.med.vision.

> Dear Prevention-minded friends,
> Subject: Why "weak" bifocal studies FAIL.
> I have been asked to "explain" why some of
> these bifocal studies fail. Rather than I explain
> it -- why not listen and understand from a
> second-opinion expert.
> Otis
> ============================
> January 21, 1997
> Journal, American Optometric Association
> Dear Editor;
> I eagerly turned to the article titled, "Can bifocals slow
> myopia progression?" in the December issue (Vol 67, no 12, pp
> 749-54) of the Journal of the American Optometric Association. As
> the director of the Kraskin & Skeffington Institute, the
> International Center for Education in Behavioral Optometry and the
> founder of the Baltimore Academy for Behavioral Optometry, I teach
> courses which cover the use of plus lenses in the management of
> nearpoint vision problems. Although the article as published
> showed some positive effect, its protocol was seriously flawed, as
> have been nearly all research protocols of this type. I am
> continually amazed at the resources that are consumed attempting
> research where the protocol dooms the study to either failure or
> minimal effect before the first patient has been seen.
> A significant body of literature exists related to the use of
> plus lenses. 1-5 Prescribing plus lenses to reduce a patient's
> stress response to sustained near point activity must be done in
> an individualized way. Studies by Darrell Boyd Harmon show that
> statistically the most appropriate lens can be derived for a group
> or cohort of people. 4 However, once derived for a group, due to
> high individual variance and high sensitivity to slight changes,
> the plus lens power derived from a group cannot be used for all of
> the members.
> The study conducted by Fulk and Cyert, as well as every study
> that I am aware of relating to progressive myopia which looked at
> the use of plus for near, has selected for its study a single lens
> power to be used by all subjects. NOTE: Each study has used
> different criteria to derive the lens power used, but all used the
> same power on all members of a particular group. This is a
> critical flaw that was carried through in the work by Fulk and
> Cyert.
> A critical aspect of understanding the use of plus lenses to
> decrease the stress response of the patient at near is the fact
> that there is a high degree of sensitivity to near point plus and
> that each person is different. Dr. Darrell Boyd Harmon and Dr.
> Robert Kraskin, in the development of their technique called
> stress point retinoscopy, have provided a method of assessing the
> degree of lens which will maximally decrease near point stress
> responses. 5 Other physiological data, as well as a number of
> articles, 2-3 clearly demonstrate that the amount of plus varies
> on an individual basis, as well as validating the concept that too
> much plus is just as bad or ineffective as too little.
> The protocol of Fulk and Cyert led them to select +1.25 adds
> for all members of the study, based on esophoria. This decision
> must be called into question. It would be rather easy to set up a
> protocol that could be made inter-tester reliable and that would
> take into account the individual differences between members of
> the study, yet have a uniform criteria upon which to provide each
> subject with the lens which clearly reduces near point stress
> response maximally. In other words, an algorithm could be
> provided which would be the same for all members of a test group,
> but which would yield different lens powers depending on the
> variances and needs of each individual. In this way, the effects
> of the lenses would be maximized and a significantly greater
> positive effect of each lens would be obtained.
> It is my hope that in the future academicians who have
> procured funds for much needed research do not squander those
> funds and the good will of the public by using protocols which
> have little hope of showing effects. These flaws reveal
> themselves most when research is being performed in a clinical
> area in which significant expertise exists about which the
> academicians are generally either uninformed or misinformed. It
> seems that Fulk and Cyert are not in tune with how the majority of
> those who work with patients to prevent progression of myopia go
> about deriving the appropriate plus lens power for near.
> What is needed are more open lines of communication between
> those doing research in clinical areas and with the clinicians who
> provide this type of care. Proposed protocols such as those used
> by Fulk and Cyert could have been circulated among a panel of
> clinicians in behavioral vision care and the points raised in this
> letter would have easily surfaced before so much time, effort, and
> energy were consumed.
> To avoid these types of problems in the future, the Kraskin &
> Skeffington Institute offers to assist anyone doing clinical
> research relating to the use of lenses, prisms, and/or vision
> therapy by reviewing, or have reviewed by appropriate experts, any
> proposed research protocol for the purpose of making
> recommendations to be communicated to the researcher. By acting
> as a bridge between those who are best equipped to do research and
> those equipped with the clinical expertise, better research should
> result, as well as better communication between academia and
> clinicians.
> Sincerely,
> Paul Harris, O.D., F.C.O.V.D., F.A.C.B.O.
> Director of Education
> References
> 1. Birnbaum MH. Management of the low myopia pediatric patient,
> J Am Optom Assoc 1979;50(11):
> 2. Greenspan SB. A study of near point lenses: effects on body
> posture and performance", OEPF, 1975
> 3. Greenspan SB. Behavioral effect of children's nearpoint
> lenses, J Am Optom Assoc 1975,46(10):
> 4. Harmon Darrell Boyd. "Notes on a dynamic theory of vision"
> OEPF
> 5. Kraskin, Robert A., "Lens Power in Action", OEPF both volumes,
> October 1981 - September 1983
> =========
> Note: On this same article Dr. Paul Harris felt that although the
> article showed some significant effect from the use of bifocals,
> the actual protocol used by the researchers reduced the effect.
> He wrote the following letter to the editor which has been
> accepted for publication and which should appear in the next issue
> of the Journal of the American Optometric Association.

> Dear Prevention-minded friends,
> Subject: Why "weak" bifocal studies FAIL.
> I have been asked to "explain" why some of
> these bifocal studies fail. Rather than I explain
> it -- why not listen and understand from a
> second-opinion expert.