Tinting of Acrysof Toric IOL's and Astronomy

[MrAstro]

I'm about to have some implants put in and I'm a keen amateur astronomer who enjoys observing faint galaxies at the bounds of dark adapted vision using averted vision. My vision pre-operation is +6.5 with some astigmatism and +8 with reading glasses (hyperopic)

I note that Acrysof Toric IOL's seem to be tinted. The best info I could find suggest that it cuts about 30% of blue light.

This worries me because I don't want to reduce the light that reaches my dark adapted eyes at all - in fact the whole point of increased aperture on astronomical telescopes is to maximise light and ensure every photon reaches your eye.

Can you allay my fears about the tinting at all - or should I worry about it and intervene in terms of the choice of lens that my refractive surgeon would otherwise implant.

I also note the lens is 6mm - I always thought a dark adapted pupil could be up to 7mm in size.

I'm currently 43 years old.

[Ringo999]

Hi Mr Astro,

A few points for your consideration;
* The yellow tint (violet or blue blocking) is designed to filter out potentially harmful rays, but it does alter colour perception, as is evidenced by many patients who have an untinted lens implanted in one eye and a yellow lens in the other. They often can notice the difference. Whether this would affect your work, I don't know?
*You mention you are hyperopic with some astigmatism. To my understanding, the Alcon lenses are available in 0.50Dincrements for common dioptric powers for the spherical component of the lens and for the cylindrical component that corrects for the astigmatism they come in 0.75Dsteps. This means that you will get a lens that is the closest fit. There are more recent advances in manufacturing that have allowed some European manufacturers to offer custom made toric IOLs that are manufactured to your exact requirement in 0.01D increments for both the spherical and cylindrical component. This may in fact have a greater impact on your ability to see well post surgery? These lenses are not available in the US? Not sure where you are based? Oculentis in Germany offer the lenses manufactured to 0.01D and Lenstec offer them to 0.25D. I am not sure if you can get the later in the US. Oculentis offer a yellow lens, not sure about Lenstec.

Good luck with whatever you choose and it will be nice for you to hopefully not need your +8 glasses all day long anymore!

[MrAstro]

I noticed that too Jodie and I'm very sceptical that a filter would increase scotopic vision.

How many eyepiece manufacturers for astronomical telescopes sell them with integral filters. (rhetorical question)....

Any filter is going to decrease the available light reaching the eye - even if it is in a narrow spectral range.

Notice that they say it increased under different assumptions - I'd like to know what those assumptions were - maybe it was a light source which didn't include the filtered wavelengths :-)

The ridiculous thing is age related macular degeneration would occur in people with a yellowed natural lens anyway - so much for blue filtering (via natural biological processes) preventing age related macular degeneration.

I sort of want to take some action regarding my lack of choice - but like I think I mentioned earlier I feel a bit powerless in the matter. My pre screening examinations cost $600 - it's hard to back out and find someone else - and then the other manufacturers lenses aren't without problems either (notwithstanding that they might be clear).

The frustrating thing is I bet it would be easier for them to manufacture a clear lens than a yellow one.

[achillea]

Here is a more recent evaluation of tinted vs untinted lenses, published under the same aegis you find suspect:

http://www.touchophthalmology.com/articles/blue-light-filtering-intraocular-lenses?page=0,5

It is of course possible that the information contained in these papers may be tainted by commercial interests, but for those with some background in physics, such as MrAstro, the plausibility of the arguments be significant.

[JodieJ]

I downloaded and read the paper you referenced.  The author is a paid consultant for Alcon (the manufacturer of Acrysof IOLs), as stated clearly in the paper.  (How could I have known this before even downloading the paper?)  I've been told that the fees paid to a consultant involve six figures in terms of US dollars.  This makes me more than a little sceptical about any "genuine concern about damage caused by exposure to certain wave lengths" on the part of the author.

I was not able to find any credible evidence that Alcon's blue-light blocking feature helps to prevent age-related macular degeneration.  As I recall, the basis for this claim was some weak correlational findings that did not hold up to re-evaluation.  On the other hand, I could find no credible evidence that this feature was in any way harmful.

[Craig10x]

Oh just to clarify, i didn't mean tint i meant the ultraviolet light filtering..whatever that is...LOL

[Craig10x]

I have Acrysof Toric IOLs with the blue tint...no color problems at all..in fact, my color perception is better then it has ever been, certainly better then when i was nearsighted and wore glasses (prior to developing cataracts)...