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Author Topic: What do you see with an IOL-Vip implant?  (Read 3125 times)

Offline Don_1

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What do you see with an IOL-Vip implant?
« on: 11/01/2013 14:57:37 »
Doing a little research for a relative on Age Related Macular Degeneration (AMD), I found a good deal about intraocular lens implants for visually impaired people (IOL-Vip).

Retina cells at the centre, and directly over the Macular, would have been damaged by seepage from capillaries in the Macular (wet AMD) or simply stopped working due to lack of blood supply (dry AMD). They are rendered inopperative and the sufferer percieves a blank spot where central vision would have been. In the early stages, wet AMD can be treated with an injected vascular inhibitor.

It is only in the case of those those suffering from end stage AMD that IOL-Vip can be offered. The proceedure involves replacing the eye's lens with two artificial lenses. These magnify light entering the eye and redirect the light on to a part of the retina unaffected by AMD.

Since this moves central vision from the centre of the retina by perhaps 2mm or more, does this mean that what is directly in front of you, and would normally be concieved as such, would now appear to be slightly to one side and would it appear to overlap (as if to give a double exposure) on peripheral vision?

I did note that following IOL-Vip treatment, patients must go through 'retraining' to get used to their new vision.



 

Offline evan_au

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Re: What do you see with an IOL-Vip implant?
« Reply #1 on: 11/01/2013 21:59:41 »
My father has AMD in one eye, and is receiving treatment to slow its progress in the other eye.

The Macula (and specifically the fovea) has the highest concentration of cones in the eye. The remainder of the retina has relatively low resolution.
This means that when my father's vision is tested in the eye with AMD, he has no central vision, but he does have peripheral vision; the acuity in the periphery seems to be about 25% of the central vision in the "good" eye (ie the letters have to take up about 16x the area for him to read them reliably with peripheral vision).

The effect of the IOL would be that:
  • You would still be able to see straight ahead, instead of squinting off to the side of where you are going
  • The view "straight ahead" would appear where you are used to seeing "off to the side".
  • This would be very disorienting at first, and would need some training and experience to get used to it. Past experiments with vision-distorting glasses suggest that you need to be very careful for about the first 2 weeks, and then it should start to feel "natural".
  • Without magnification, you would need to read large-print books/web pages
  • With magnification, you may be able to read normal print, but the visual field would be reduced.
  • In redirecting central light, you would lose peripheral vision in that eye.
  • Perhaps it is best to have the operation in just one eye, so that one eye retains peripheral vision (important for safety), and one eye can see straight ahead for walking and reading?
  • Perhaps also the IOL could have minimal magnification so there is a minimal "hole" in the visual field, but to use magnifying glasses or a hand lens to give increased resolution when reading?
  • If the AMD is not under control, the area of central vision loss may expand over time. You wish to avoid subsequent operations to change the IOL.
   
See http://en.wikipedia.org/wiki/Macula
http://en.wikipedia.org/wiki/Macular_degeneration
« Last Edit: 11/01/2013 23:24:59 by evan_au »
 

Offline Don_1

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Re: What do you see with an IOL-Vip implant?
« Reply #2 on: 14/01/2013 13:21:25 »
Thanks evan_au, you have confirmed my thoughts on this matter.

My uncle has dry AMD in the left eye and now his right eye is developing the same condition.

I did find the Macular Society web site quite helpful and have suggested he join the society for help and advice.

macularsociety.org
 

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Re: What do you see with an IOL-Vip implant?
« Reply #2 on: 14/01/2013 13:21:25 »

 

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