Hi Buffy,
Can you either look up your case files or find in a science paper?
The statistics on the strength of myopia (dioptre) as a percentage.
eg. perhaps 15% have average strength 1 to 1.5 dioptre etc.
There are some figures in the prevalence and incidence section of this paper. But it is different in different places/racial groups.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3340784/
And this one takes quite a big of reading:
http://www.ncbi.nlm.nih.gov/books/NBK235054/
buffy said:
There are some figures in the prevalence and incidence section of this paper. But it is different in different places/racial groups.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3340784/
“myopia now affects epidemic proportions of adults from 85% to 90% in Asian cities.”
mollwollfumble said:
buffy said:There are some figures in the prevalence and incidence section of this paper. But it is different in different places/racial groups.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3340784/
“myopia now affects epidemic proportions of adults from 85% to 90% in Asian cities.”
OMG. That’s an incredibly high proportion.
Yes, and they come here and we get infected with it.
buffy said:
And this one takes quite a big of reading:
http://www.ncbi.nlm.nih.gov/books/NBK235054/
Table 3 is what I’m looking for. It’s a pity there’s nothing more recent than the 1950s. (PS. I noticed the same lack of recent data when looking for weight vs age statistics).
TABLE 3 Myopia Prevalence of Various Degrees Among Adults, 1929-1950
Spherical Equivalent Refraction Scheerer (1928) & Betsch (1929) Walton (1950)
-.62 to -1.50 5.5 7.8
-1.62 to -2.50 2.5 3.4
-2.62 to -3.50 1.5 2.4
-3.62 to -4.50 1.0 0.7
-4.62 to -5.50 .5 0.5 (-5.50 to -8.00)
-5.62 to -6.50 .5 1.0 (-8.25 to -11.00)
-6.62 to -10.50 2.0 >0.1 (-11.25 to-14.00)
-10.62 and greater 1.0 >0.1 (-14.25 and over)
mollwollfumble said:
buffy said:And this one takes quite a big of reading:
http://www.ncbi.nlm.nih.gov/books/NBK235054/
Aha,Table 3 is what I’m looking for. It’s a pity there’s nothing more recent than the 1950s. (PS. I noticed the same lack of recent data when looking for weight vs age statistics).
TABLE 3 Myopia Prevalence of Various Degrees Among Adults, 1929-1950
Spherical Equivalent Refraction Scheerer (1928) & Betsch (1929) Walton (1950)
-.62 to -1.50 5.5 7.8
-1.62 to -2.50 2.5 3.4
-2.62 to -3.50 1.5 2.4
-3.62 to -4.50 1.0 0.7
-4.62 to -5.50 .5 0.5 (-5.50 to -8.00)
-5.62 to -6.50 .5 1.0 (-8.25 to -11.00)
-6.62 to -10.50 2.0 >0.1 (-11.25 to-14.00)
-10.62 and greater 1.0 >0.1 (-14.25 and over)
Nobody is much interested in the basic stuff now. They think it has all been done. Try finding age related measurements of blood pressure.
I have longitudinal data on myopia because my practice is old. But no-one is interested in looking at it. Even when I offered it tabulated, ready to look for trends etc. So it will die with my practice. People do not go to the one practitioner for extended periods now. Long term in the current research world is two years. Be especially careful with myopia data in terms of time too. Myopia does not, in the real world, progress in a nice steady fashion. It tends to fits and starts (forgive me, I did stats 40 years ago and can’t remember the terminology). So, for example, you read some research and they say that whatever method they are investigating halted or reduced the speed of myopia development. For 12 months. I’ve even seen them report a 6 month retardation of development. It is quite likely the child simply wasn’t in a growth spurt at the particular time they were in the research program. And only very rarely do I see any research which then removes the “cure” to see if there is rebound. Which I suspect might be the case.
My current beef with the research is in the area of orthokeratology. In which a hard contact lens is used to shape the cornea and slow down the progression of myopia by flattening the cornea. Not to put too fine a point on it, I think this is going to end up in the same drawer of history as foot binding. Which was not at all the right thing to say to a top researcher in the area. I just have a complete disconnect with how it could possibly work. My big bugbear is that high myopes (>6.0D) have a higher risk of retinal detachment – there is absolutely no dispute about this. So we need to stop them getting to be high myopes. I pointed out that as the cornea is embryologically completely differently derived than the retinal tissue, squishing the cornea is unlikely to make much difference to whether you have a brittle retina likely to fall off.
I did not receive a reply from the researcher when I put this to her by mail.
> I have longitudinal data on myopia because my practice is old. But no-one is interested in looking at it.
I am! Original sources are always valuable. Next time I’m passing your place I’d love to have a look.
> Myopia does not, in the real world, progress in a nice steady fashion. It tends to fits and starts …
… mine did. At one time I improved by one dioptre in one eye and 0.75 in the other eye, over a period of a about a fortnight. Since then it’s more slowly gone back to where it was before.
> My current beef with the research is in the area of orthokeratology. In which a hard contact lens is used to shape the cornea and slow down the progression of myopia by flattening the cornea. Not to put too fine a point on it, I think this is going to end up in the same drawer of history as foot binding.
I tend to agree.
> high myopes (>6.0D) have a higher risk of retinal detachment – there is absolutely no dispute about this. So we need to stop them getting to be high myopes.
That makes sense.
I keep wondering if there’s any connection with a rare genetic disorder called Marfan Syndrome. Marfan syndrome is caused by a faulty gene that affects connective tissue. It causes increased height, heart problems, and IIRC retinal detachments. Which makes me wonder if taller people without Marfan Syndrome are also more prone to this sort of eye problem.
Sorry, I didn’t get back to this thread until now. Marfans tend to dislocation of their lenses as the suspensory ligaments are weak.
Contact me on acianthus@ansonic.com.au moll and we could see about the myopia information. I’ve sort of given up on it, but I do have it all on disc (I think..I’ll have to see) A colleague got some of his students to play around with it a bit, but then he got a better job up the ladder and things fell apart. I have offered it to various people that I know are doing myopia research, but I’m just a clinician. I don’t rank.