Help at Work II

[Barney]

On the point you made though Alison, I'm sure you're right that the evidence would need to be very strong before the case was popularly accepted. The industry would do all it could to produce counter evidence and finance any research that helped its cause. There's no financial incentive to prove that any contact lenses might harm eyes unless there is an alternative more profitable product. Look at the tobacco industry. And we still wear high-heels with pointy toes (well not personally) even though we know they causes nasties like bunions and Morton's neuromas.

Putting a piece of rigid plastic in the eye hurts like heck until the body gives up warning us. Could be we should sometimes pay more heed to what our body's warning system is telling us. Even with the obvious benefits for KCers I think any possible downside should be explained to them.

[John Smith]

What is clear is that it is not a blue eyed, blond haired sort of disorder as much as it is a dark eyed and dark haired one... and if it was then I think things would have moved more quickly with break throughs in Keratoconus.

I think that's a bit unfair. Discounting those among us who get their blonde hair from the chemists, the population of the UK is largely NOT blue-eyed blond(e).

So any study which finds that x% of people with KC are dark haired needs to compare x with the proportion of the population that is naturally dark haired.

For the record, I know at least four blue-eyed natural blond(e) people with KC, including myself!

[Anne B]

My hair was naturally blonde as a child( i do have a bit of help now!!) and i have blue eyes.

Anne

[Sajeev]

Its only a rough poll john, it did show that there was a group of blond haired and blue eye KCers around, yet it showed a pattern like the one below. And Dr's have seen this, with one telling me that its because they have weaker corneas the dark eyed/haired ones.

Here is what the latest KC newletter says about the pattern seen in transplants (please read below) In summary Afro-carribeans need more transplants, with whites needing the least and asians coming somewhere in between.

http://www.keratoconus-group.org.uk/new ... conus.html

[Matthew_]

I think the blonde hair / blue eye argument is weak. Blue eyes are caused by recessive genes: they are a minority of the population. So where in the world are you likely to find a dominant blonde/blue population that will provide a representative sample? (Don't say Norway or something! Most of Europe is now very well mixed.)I can understand the race argument to some extent because different races do have different and demonstrable traits caused by genes. I think hair and eye colour are a separate if related issue. Blonde haired / blue eyed people are not a separate race, it is possible for any race to posses these traits although they are mostly found among caucasians. Such individuals are well mixed within the population anyway, so how would you trace any KC this way. The first blond to have a dark haired child with KC is a threat to the hypothesis. I just don't think it stands statistically or on a common sense level!

[Sajeev]

Matthew read the study done in saudi arabia and the transplant one by Mr Tuft... blonds with blue eyes are not for the most part afro carribean or saudi arabian generaly speaking, its just a rough thing in charactistics.

[Andrew MacLean]

the problem with these guide principles is that they are often wide of the mark.

I had gall stones when I was 36 (too many fish suppers!) At that time I weighed 10 and a half stone and was running six to ten miles, three or four times a week.

The surgeon who operated on me joked about the "guide principles" for gall stones was that they looked for them as the cause of pain in people who were "fair, fat, female and forty'. I was none of those things, although I do own up to being overweight and over forty now.

If there is a general tendency for people from one ethnic group or even racial group to exhibit Keratoconus more than other ethnic or racial groups, then it does not follow, nor does it suggest that KC will be absent from all other groups.

By the way a racial predominance does not lead automatically to the conclusion that there is a genetic element in the cause of KC. It may simply be that people from different racial or ethnic groups are more likely to share environmental factors than those of different race or ethnicity.

[Matthew_]

Hear, hear Andrew!
The problem with all these studies mentioned is they just have no statistical clout! And how could they? The assertion is that hair and eye colour (independent variable) is correlated with KC (dependent variable). Good luck with that! There are too many other factors that you simply could not control, environmental factors. These environmental factors could be associated with locations of certain ethnic groups so you cannot even be sure its genetic let alone specific genetic traits!
Personally, my unsubstantiated belief is that KC is polygenic ie a mix of genetic and environmental causes. But as soon as you try to assert that it is one or the other you are deep trouble! These studies cannot be used to support such hypotheses. That doesn't mean you are wrong necessarily, it just means you cannot prove it to any degree of statistical significance that would be accepted by any scientific community.

[Sajeev]

"Clinical Study

Influence of ethnic origin on the incidence of keratoconus and associated atopic disease in Asians and white patients

T Georgiou1, C L Funnell1, A Cassels-Brown1 and R O'Conor1

1Dewsbury District Hospital, Yorkshire, UK

Correspondence to: CL Funnell, C/o Ophthalmic Secretaries, Clarendon Wing, Leeds General Infirmary, St George Street, Leeds, Yorkshire, LS1 3EX, UK. Tel: +44 113 2432799; Fax: +44 113 2926239; E-mail: c.l.funnell@doctors.org.uk


Presented as a Poster at the Annual Congress Manchester 2002


Abstract

Purpose To investigate the influence of ethnic origin on the incidence of keratoconus and the association of atopic diseases in patients with keratoconus.

Methods Retrospective study of new patients referred to Dewsbury District General Hospital and diagnosed with keratoconus in a 6-year period between 1994 and 2000. The ethnic origin of the patient was defined as white, Asian, or other. Incidence was calculated from the catchment population of 176 774 (82% white people, 17% Asians, 1% others). t-Test, confidence intervals and 2 tests were used to show statistical significance.

Results A total of 74 cases of keratoconus were diagnosed over this period. Of these patients 29 (39%) were white and 45 (61%) were Asian. This equated to an incidence of keratoconus of 25 per 100 000 (1 in 4000) per year for Asians, compared with 3.3 per 100 000 (1 in 30 000) per year for white people (P<0.001). Asians presented significantly younger than white patients. The incidence of atopic disease was found to be significantly higher in white compared to Asian keratoconic patients.

Conclusions Asians were significantly more likely to present with keratoconus. The Asian patients were mostly of Northern Pakistani origin. This community has a tradition of consanguineous, especially first-cousin marriages. The higher incidence in this population was highly suggestive of a genetic factor being significant in the aetiology. The incidence was higher than revealed by previous studies. Atopic disease was significantly less common in Asians compared to white people, supporting the theory of a different aetiology in these patients."

[jayuk]

Matthew and Andrew

Just remember, that 99% of all statistics are rubbish! And 1% are almost erroneous!

Jay