Advice on Cataract Surgery IOL Selection
Posted , 8 users are following.
This is the best cataract surgery forum on the internet. I am 75, dense cataracts in both eyes, have been nearsighted and have worn eyeglasses since childhood, I have 2 diopeters of astigmatism, I know a toric IOL could fix my astigmatism, but I want to keep my surgery simple and go with a Technis monofocal and fix my astigmatism with eyeglasses.
It seems most patients have the IOL set for distance, while a few opt for intermediate vision. I told my eye surgeon I like seeing my face without glasses when I shave, and he suggested I should go for near vision, but left the choice up to me. I work an office job and spend a lot of time on the computer. Can a case be made for near vision? That's about 12 inches, right.? Or would intermediate be better? Thank you all.
1 like, 21 replies
jimluck donman
Edited
Going for near vision makes perfect sense to me. My computer glasses can live by my computer. My driving glasses can live in my car. But, I might have to read, unexpectedly, anywhere. I want to be able to take off my glasses anywhere, any time, and read. I don't want to be one of these people who is always looking for their reading glasses or asking to borrow someone else's. Plus, you could probably still read close up with 2 diopters of astigmatism, but not read street signs in the distance. So, it makes sense to target the near distance and have some useful glasses-free vision. I have a lot of astigmatism, and myopia, but can see clearly (and read my phone comfortably) very close up despite the astigmatism. If you target distance and don't correct the astigmatism, you'll probably need glasses for both reading and distance.
When people say "targeting -2" they mean the amount of myopia that would require -2 sphere in a glasses prescription to get to 20/20. Usually, someone with that amount of myopia (and no astigmatism or fully corrected astigmatism) can read comfortably, and their sharpest vision will be at about 18 inches. For sharpest vision at 12 inches, I think you would want to be at about -3. Reading glasses, or the reading portion of a progressive are usually around +2 to +2.75 for old people, which makes an otherwise 20/20 wearer see like a myope who needs -2 to -2.75 lenses to see 20/20 at distance. I am leaning toward targeting -2 for myself, figuring that will make my near vision good enough for all purposes and not wanting to sacrifice more distance vision than I have to.
Note that you may not have 2 d of astigmatism after surgery. Some astigmatism is (or may be) in the cornea and some in the lens that is being removed. The incision and healing of same may change the shape of the cornea and therefore the amount and axis of the corneal astigmatism. The lens part of your astigmatism, if any, ("lenticular" to say it right) is going down the drain with the destruction of your natural lens.
Today I had an optometrist try scleral contact lenses on me with no prescription in them. These pretty much automatically eliminate corneal astigmatism. (They are a type of hard contact. Since the contact lens becomes the refracting surface, the shape of the cornea becomes irrelevant to what you see.) Then they tested to see what glasses prescription I would need with the lenses on too. There was still lots of astigmatism in both eyes, they found. So that means lots of my astigmatism is going to go away when they take out my natural lenses. Unfortunately, I'll still have lots in my corneas.
Dave13852 donman
Posted
Jim I was going to attempt to explain diopters to Donman but you did a much better job than I could have. The only thing I'll add as Ron and the others mention is that the surgeon could sometimes miss by .5D or so to either side of the target.
Jim will you be comfortable with reading near from 18" or so on your phone? What if the surgeon misses and you end up -1.5D which would give the best near vision at around 26"? That said I agree with you about not wanting to sacrificing more distance than need to.
Always a tradeoff. I know some will mention monovision but I don't know that for myself I would be able to handle the inbalance or at least targeting for the inbalance. I know others like Bookwoman that ended up with a slight difference (mini monovision?) and are extremely happy with their outcomes!
donman
Posted
Jim
I appreciate your reply and explanation for -2 and other optical terms, and for what you said about astigmatism. I also have dry eye disease and droopy eyelids, which my surgeon said may be aggravated by cataract surgery, but can be addressed later. I am using artificial tears now. I didn't even know I had dry eye disease until I was tested for it. Also, droopy eyelids can sometimes affect IOL calculations, especially as they relate to astigmatism when a patent wants a toric lens, so I opted for a regular monofocal.
Dave, thank you also for your advice.
RonAKA donman
Posted
Some additional thoughts. You mentioned that you wanted to keep it simple and avoid a toric lens. A toric lens implant is pretty routine for any competent ophthalmologist. They do have to be accurate in their astigmatism measurements and mark the eye accurately before inserting the lens, and get it into position, but that is about all there is extra. However there is a cost if you are paying. Where I am, a basic monofocal is free, but a toric costs an extra $1,100 per eye. But, if you are looking for some relief from glasses, getting a toric lens is the way to go, and is not high risk at all.
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If you were to get a toric lens that would open the door to get mini-monovision which can extend your range of vision from say 15" out to infinity if you target -0.25 D in your dominant eye, and -1.5 D in your non-dominant eye. Essentially that is what I have and almost never wear glasses. Today I wore some +1.25 D readers for the first time in probably 2-3 weeks. Was doing some work on my garage door that required me to get my nose right up to the work. With my -1.5 D eye for close work, it starts to jam out at about 12", and when you are forced to be closer than that, then readers are needed. But, other than that I never wear them. I never take glasses with me when I leave home, and almost never wear them at home. So being eyeglass free is an option, but to make the best of it you should get toric lenses.
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If you go non toric you should ask what your spherical equivalent will be with the various lens choices. The IOL calculation sheet the surgeon will have gives that for each lens. If you have significant residual astigmatism that will contribute to your spherical equivalent and should be considered in deciding which lens you want to go for. And you do not need both eyes to read and see close. Consider going with a spherical equivalent that leaves you myopic in the non dominant eye, but not so much in the other eye. That will give you a wider range of vision without glasses on. And, it makes no difference when you put glasses on as they will correct for whatever option you choose.
donman
Posted
Ron, I am just now replying to your post. I don't understand what you were saying about "spherical equivalents and the IOL chart." But I did tell my surgeon I was thinking about intermediate for my left eye (non-dominant) and he said that he could do near for my right eye, (dominant). I have seen other eye surgeons in another city who advised me that at my age and with my "perfectionist personality," I shouldn't go with mini-mono-vision. But maybe if it was something less than mini-monovision, like mini-mini-monovision, it might not be too much of a change for me. Is that what you were suggesting?