A question, but not keratoconus related

[Antoine]

I doubt this is the right place to ask, but i'm trying to find some information on damage to the ciliary body/ suspensory ligaments which occurs naturally in the ageing process. Which would cause presbyopsia in old age, as the lens in theory should remain in a myopic state. Or maybe i am wrong and it is the lens that becomes damaged.

My knowledge on eyes isnt that great, as i'm only an a level student, trying to do a piece of coursework investigating loss of visual function in relation to age. I've searched which seems like forever and all in the information i find is either too vauge or the literature is too advanced that i dont understand it. If anyone is able to point me into the right direction i would much appreciate it, so information on 'natural' causes of vison loss is what i'm looking for. Bad use of the term i know.. just i'm not looking for information on eye problems like amd, glaucoma etc. Anyway. Thanks

[jayuk]

Your probably looking for data on

Glaucoma
Cataracts
Macular Degeneration
Diabetic Retinopathy

The above are the four most common causes for age related vision loss......Im pretty sure you can steer yourself from here...if not feel free to PM me.

J

[Antoine]

I have enough information on these disorders, to give them a name.

As i have to test people, which i'll use a snellen chart to do i have do analyse my results etc, so i cant really go into too much about amd, glaucoma, cataracts and that.
As not everyone will suffer from the problems mentioned, so i was hoping to find some evidence of vision impairment with age due to ageing. I read some things on development of axial myopia occuring in later life, however there is conflicting evidence into what the causes are. As i have to relate it to other areas of my a level specification finding some info on ageing of the ciliary body would be striking gold.

[John Smith]

Hi Antoine, I hope that you find the info you're looking for; hopefully one of the optoms who post here will be able to help you.

[Andrew MacLean]

Antoine

Well done on your choice of topic. Presbyopia (the word has two roots: presbus ‘old man’ + Ã…Â

[Antoine]

Thanks for the feedback, i guess i chose a slightly ambiguous area to study

I read some work by
Adrian Glasser ~ Biometric, optical and physical changes in the isolated human crystalline lens with age in relation to presbyopia

and; Age related changes in accommodative dynamics in humans.

Some of the information is way over my head, and to try and simplify the key points into words everyone can understand is quite tricky. Anyway, thanks again.

[Christine Wright]

It's hard to help, without knowing the level of detail you need . You're right, you need to steer clear of eye diseases if you're looking at "normal" aging. The most obvious of these is presbyopia, as has already been said - the blurring of near vision. I've just put 'presbyopia' into Google and it came up with quite a lot of sites - the Wikipaedia one seemed to answer your question, saying that the most common theory is that it is caused by loss of elasticity of the lens, with age.

There are other things that happen with age, such as decreasing of the pupil size, the need for more light etc. I think you need to go back to your teacher/supervisor for some more guidance on what the project should include and how to go about it. That's not the same as asking them to do it for you!

Good luck

[Sajeev]

First of all it can be corrected with reading glasses or laser, so nothing is damaged as such, its just (i think so anyway) age related in that the elasticity of the lens and ligaments is not up to scratch to change the focus properly.

Antonie, thats some good reseach and thinking, your doing there.

The progression towards long-sightness as we age, ain't that helpful for us folk with KC?

[Antoine]

It's hard to help, without knowing the level of detail you need.

I've just put 'presbyopia' into Google and it came up with quite a lot of sites - the Wikipaedia one seemed to answer your question, saying that the most common theory is that it is caused by loss of elasticity of the lens, with age.

There are other things that happen with age, such as decreasing of the pupil size, the need for more light etc. I think you need to go back to your teacher/supervisor for some more guidance on what the project should include and how to go about it. That's not the same as asking them to do it for you!

Good luck

Well for what my work needs to include, she wouldnt know, as we chose our choice of coursework independently with some guidelines from the exam board.

The level of knowledge i need to include needs to be pretty in depth, something like a definition from wikipedia wouldnt cut it
I've found enough relevant research, the examining body isnt so likely to check up everything about presbyopsia, so aslong as i have at least 1 underpinning study to support my hypothesis then that is fine.

I do need some instructions of how to use a snellen chart properly, i read something about it has to be placed 5 minutes of an arc, whatever that means. Also it seems a little contradictory to use a snellen to support or reject loss of vision due to ageing, as i read presbyopsia effects near vision and not distant vision. Is it possible to test participants using the snellen chart at varying distances? So i could test their normal visual acuity from 20 feet, then test at closer distances to show that near vision is lost in the older participants.

If you could explain how to use a snellen chart properly and if its possible to test people at varying distances with the snellen that would be much appreciated it. By possible i mean that it would provide reliable results.

Thanks

[John Smith]

Antoine,

The Snellen Chart on our site has been calibrated to be accurate if printed at 100% scale and viewed from three metres away.

This means that the back of your heel should be 3m from the wall on which you stick the printout!

It's not quite as accurate as a standard 6m chart, but not many of us have rooms that long!