Correction: School Children -1/2 D per YEAR

Discussion in 'Optometry Archives' started by otisbrown, May 14, 2007.

  1. otisbrown

    otisbrown Guest

    Dear Ms. Brainy,

    Sujbect: Please correctly quote the facts.

    In these so-called bi-focal studies, (six of them)
    the CONTROL group went down at an average
    rate of -1/2 diopter per year, not -1/2 diopter
    in six months.

    Just quote the clinical studies correctly -- as
    I have.

    Further, the method of PREVENTION, is not
    a Bates method at all. In fact is it supported
    by a percentage of ODs, who use the method
    on their own children to help them maintain
    a positive refractive STATE through the school
    years.

    As always, enjoy our pleasant scientific
    discussions about the proven dynamic behavior of
    the natural eye.

    Otis

    ++++++++++


    Brainy> 10 years later I moved to the big city, and a few months
    later noticed
    a new sign next door. It said "The Bates Institute". This reminded
    me of the old meeting, and I knocked on the door out of curiosity.
    By
    now my Rx increased from -1.5D to -2.5D (sorry Otis, no -.5D increase
    every 6 months as you suggest). Amazingly, it was the guy from the
    bus station, who now was my neighbor.
     
    otisbrown, May 14, 2007
    #1
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  2. otisbrown

    Neil Brooks Guest

    No, Otis. You lie by misstating statistics ... just as you do with
    Air Force Academy and Naval Academy data.

    The bottom line is/was:

    - Some myopes get more myopic;
    - Some myopes stay stable;
    - Some myopes get LESS myopic

    Therefore ....

    Liar.
     
    Neil Brooks, May 14, 2007
    #2
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  3. otisbrown

    otisbrown Guest

    Subject: The DOWN rate of the natural eye in a school
    environment.

    I would like to thank Judy for supplying the data for
    some of these six control groups.

    I always like to present the facts themselves concerning the
    natural eye's dynamic behavior.

    That way you can look at them and personally decide what you
    wish to do about them.

    The first study was conducted by Dr. Francis Young.

    The others by Dr. Judy.

    The last are studies conducted in China about myopia studies.

    If only ONE study showed that -1/2 diopter per year, you
    could call it a "fluke". But when almost all of them show -1/2
    diopter per year DOWN, you MIGHT take plus-prevention more
    seriously.

    ===============================

    Dear Scientific friends,

    Subject: The average DOWN rate of the
    control groups in these plus (or bifocal) studies.

    I have this report by Oakley-Young.

    The group using a single-minus went down at a steady rate of
    -1/2 diopter per year.

    If you have the published rates of these comparable studies,
    could you please post them.

    I will collect and publish them.

    Here is an example of one study:

    Authors:
    Kenneth H. Oakley, MD.
    Bend, Oregon

    and

    Francis A. Young, Ph.D.
    Primate Research Center
    Washington State University
    Pullman, Washington


    ABSTRACT

    "...Similarly, 226 Caucasian bifocal wearers are matched on
    the same criteria against 382 control subjects..."

    "...the Caucasian subjects of -0.02 and -0.03 diopters right
    and left eyes against -0.53 and -0.52 diopters for the
    controls..."

    +++++++++++=

    The study was conducted over a period of four years.

    I am not looking for "cause", or the "test group", only to
    establish the down rate in terms of numbers in the control group,
    and the length of time the study was conducted.

    I am also not looking for an "argument" about these issues.

    Best,

    Otis

    ====================

    Dr. Judy's report on -1/2 diopter per year
    for students:

    1. In the COMET study (children) 3 year data:

    Single vision: -0.49D/yr

    Bifocal group: -0.42D/yr

    5 year data

    Single vision, two myopic parents: -0.51D/yr
    Single vision, one myopic parent: -0.40D/yr
    Single vision, no myopic parents: -0.36D/yr
    Bifocal group, 1 or 2 myopic parents: -0.40D/yr
    Bifocal group, no myopic parents: -0.36D/yr

    2. Fulk et al, children with esophoria 30 months

    Single vision: -0.49D/yr

    Bifocal group: -0.40D/yr

    3. Parssinen (age 9 to 11) 3 yrs

    Single-Vision Dist only, SV near and far, Bifocal: -0.48D/yr

    Lin et al (young adult medical students) 5 years

    -0.14D/yr

    4. Kinge et al (engineering students average age 20) 3 years

    -0.19D/yr

    Dr. Judy

    ========

    5. A recent study in Hong Kong showed what other studies have
    shown - wearing less than a full correction will slow the
    progress of the myopia. Children selected for the study were
    between the ages of 9 and 12. All were nearsighted, with 1.00
    to 5.00 D of myopia. The children were separated into three
    groups. Each group was given a different type of eyeglasses
    to wear for the two-year period of the study. The first group
    wore single vision lenses with a full correction; the second
    group wore progressive lenses with a +1.50 add; the third
    group wore progressive lenses with a +2.00 add. All children
    were examined at 6-month intervals to check the progression of
    their myopia. Sixty-eight children completed the study. As
    expected, more undercorrection meant slower myopia
    progression.

    Minus vision lenses: - 1.23 D increase (2 years)
    -0.625 per year

    Progressive lenses with +1.50 add: - 0.76 D increase (2 years)
    - 0.38 per year

    Progressive lenses with +2.00 add: - 0.66 D increase (2 years)
    -0.33 per year

    Source: Leung JT, Brown B. Progression of myopia in Hong Kong
    Chinese schoolchildren is slowed by wearing progressive
    lenses. Optom Vis Sci 1999; 76:346, 354. Published 10/07/00.

    ==================

    The results of the natural eye "adapting" to
    12 to 16 years in a "school" environment:


    MYOPIA PREVALENCE IS ALWAYS HIGHER THAN 90 PERCENT
    FOR TAIWAN MEDICAL STUDENTS


    Re: Changes in ocular refraction and its components
    among medical students - a 5-year longitudinal study", Optom.
    Vis. Sci., 73:495-498, 1996) found that in a study of 345
    National Taiwan University medical students, the myopia
    prevalence increased from 92.8% to 95.8%! over the five year
    period.

    ******************


    1) In Singapore, the vision of 421,116 males between the ages of
    15 and 25 was examined. In 1974-84, 26.3% were myopic; in
    1987-91, 43.3% were myopic. Both the prevalence and severity
    of myopia were higher as the level of education increased.
    The prevalence rate was 15.4% in males with no formal
    education and increased steadily through the education levels
    to reach 65.1% among the university graduates in 1987-91. The
    authors state that their findings confirm indications from
    other sources that the association between the prevalence and
    severity of myopia and education attainment is real (M.T.
    Tay, K.G. Au Eong, C.Y. Ng and M.K. Lim, "Myopia and
    Educational Attainment in 421,116 Young Singaporean Males,"
    Ann Acad Med Singapore, 1992, Nov;21(6):785-91).
     
    otisbrown, May 14, 2007
    #3
  4. otisbrown

    Neil Brooks Guest

    The average is a useless, misleading statistic here. When you look at
    the data with more granularity, you find what I have told you ....
    um ... over 50 times:

    1) Some myopes get more myopic over time. Some get less myopic. Some
    stay the same:

    http://books.nap.edu/openbook.php?record_id=1420&page=33

    2) Nothing shy of chemical intervention (muscarinic antagonists/
    Atropine) has been found to alter this progression--certainly nothing
    that YOU have suggested ... otherwise, your niece, Joy, wouldn't be a
    myope with a restricted driver's license today.

    Why are you such a blockhead, Otis? Is it:

    - insufficient meds?
    - excessive meds?
    - improper meds?

    I've considered additional possibilities, but they don't fit quite as
    well as these options.
     
    Neil Brooks, May 14, 2007
    #4
  5. otisbrown

    retinula Guest

    I wonder why this study comes to an opposite conclusion that the study
    of Chung et al. (and the clinical experience of optometrists who tried
    "unofficially" for several decades to undercorrect american
    children). That study shows that undercorrection actually stimulated
    myopia development.

    1.Chung K, Mohidin N, O'Leary DJ. Undercorrection of myopia enhances
    rather than inhibits myopia progression. Vision Res. 2002, 42:
    2555-9.
    The Chung study is a small (n=94), 2 year randomized and masked
    prospective study comparing the effects of full-time undercorrection
    (UC, by approx 0.75 D) with full-time fully correction (FC) in young
    myopes (mean: -2.86 D). The study group comprised approximately 1.4
    time the numbers of girls as boys with Chinese and Malay ethnic groups
    being approximately equally represented. Over the 2 years of the
    study, the FC group showed a progression of -0.77 D compared to the UC
    group that exhibited a progression of -1.00 D. Rates of eye growth
    also differed between the two groups, as expected, being slower for
    the FC group.
    This study suggests that leaving myopes partially uncorrected (i.e.
    with a net plus prescription) may in fact promote myopia development
    rather than reduce it.


    I can't help but notice that all the other studies that you also
    posted below actually follow myopia development in a specific racial
    group -- i.e. Asian children. This is in fact evidence that one of
    the largest determinants in myopia development is GENETICS.

    Regardless, a large study recently done in China has shown that
    bifocal use has no influence of myopia progression:

    The Hong Kong Progressive Lens Myopia Control Study: Study Design and
    Main Findings
    Marion Hastings Edwards, Roger Wing-hong Li, Carly Siu-yin Lam, John
    Kwok-fai Lew and Bibianna Sin-ying Yu; Investigative Ophthalmology and
    Visual Science. 2002;43:2852-2858. From the Centre for Myopia
    Research, The Hong Kong Polytechnic University, Kowloon, Hong Kong.

    Abstract:
    PURPOSE. To determine whether the use of progressive addition
    spectacle lenses reduced the progression of myopia, over a 2-year
    period, in Hong Kong children between the ages of 7 and 10.5 years.

    METHODS. A clinical trial was carried out to compare the progression
    in myopia in a treatment group of 138 (121 retained) subjects wearing
    progressive lenses (PAL; add +1.50 D) and in a control group of 160
    (133 retained) subjects wearing single vision lenses (SV). The
    research design was masked with random allocation to groups. Primary
    measurements outcomes were spherical equivalent refractive error and
    axial length (both measured using a cycloplegic agent).

    RESULTS. There were no statistically significant differences between
    the PAL and the SV groups for of any of the baseline outcome measures.
    After 2 years there had been statistically significant increases in
    myopia and axial length in both groups; however, there was no
    difference in the increases that occurred between the two groups.

    CONCLUSIONS. The research design used resulted in matched treatment
    and control groups. There was no evidence that progression of myopia
    was retarded by wearing progressive addition lenses, either in terms
    of refractive error or axial length.

    ============================

    So I guess that all that can be concluded is, while children of Asian
    descent are more inclined to develop myopia than children of European
    descent, using plus lens adds has no effect on either of them.
     
    retinula, May 14, 2007
    #5
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