Selecting the right IOL for cataract surgery

About 3 weeks ago I didn't even know what a cataract was. Now that I was diagnosed with having one, I'm learning as much as I can. So please excuse my ignorance.

I'm a 44 year old male. I've always had glasses for distance, but my eyesight was not that bad (about 20/50 uncorrected). so I generally only used the glasses for night driving. Reading close up was always fine, but with age its startiing to deteriorate. Now small print is very difficult without reading glasses.

I was diagnosed with a cataract in my left eye, vision now 20/200  in that eye. I have a small cataract in the right eye which I will leave alone right now.

So, I'm going for the monofocus IOL in my left eye (I chose monofocus because of its proven track record, less chance of night halos and my medicare covers it). Now the big question: Which lens to choose?

My eye was measured and these are the options they gave me (using the B&L-LI61SE)

IOL 15.0     Pred. Ref. -0.25
IOL 15.5     Pred. Ref. -0.58
IOL 16.0     Pred. Ref. -0.92

Would any of these choices allow driving without glasses, reading my computer monitor, dialing a cell phone?
I would like to be specs free except for reading close up (books, newspaper). Which should I choose?

Any input would be greatly appreciated.

[Forum-OD-MP]

not enough info in that post to answer that question with any degree of real accuracy.  you need to be posing this question to the surgeon or their staff.

you gave me an acuity (20/50) but its more complicated than that.  i'd need to know your refraction, topography, ultrasound, pachymetry, etc.

we can make some reasonable assumptions, tho.  ASSUMING they have measured accurately and the surgery goes w/o complications and the IOL is reasonably centered and you do not have an inflammatory reaction:

the -0.25 will probably be blurrier at distance and intermediate, but clearer up close

the -0.58 will probably be clearer at intermediate distances (like the computer) but blurrier when reading and driving

the -0.92 will likely be the clearest at distance but the blurriest at near

some of this also depends on what the prescription of the other eye is.  are you going for a monovision effect?

[sergmick]

Thanks for your response. I'm a bit confused. I thought the pred. ref of -0.25 would be the one most appropriate for distance, and choosing the -0.58 or the -0.92 is like moving the focus point in a bit (closer to intermediate range). Please correct me if I'm wrong.

I'm not going for the monovision effect, although my good eye can read the monitor and cell phone , no problem.

[JodieJ]

Your post totally astonishes me!  The figures you give seem to be the output of an IOL Master (e.g., predicted vision with an IOL in power 15 is -.25D, etc.)  Are you actually telling us that your surgeon gave you this output so that you could choose the IOL power that best suits your post-surgery visual goals?  And did you say that you used to drive sometimes without your glasses?  Actually, your numbers are very similar to mine, and I'm so nearsighted (-5.50D) that I'd have trouble finding my car without my glasses or contacts.  No offense, but I hope you don't drive in my state.

[sergmick]

The technician making the measurements gave me the data because I kept asking questions. I guess she figured I would be able to understand more by seeing the results (she made me a copy). Yes, I drive without glasses, sometimes. Apparently the good eye (right) has about 20/50 uncorrected. The technician said my right eye is currently -1.5D without correction (whatever that means). If you're afraid of my driving, just stay away from florida (LOL).

Anyway, I read somewhere on the internet (which we all know is always right) that if your eye has a -1.0D after the procedure, then you far vision would be around 20/40 and your intermediate vision wouldn't be so bad either (20/40). Is this accurate?

Any comments welcome.

[JodieJ]

So, your right eye was about -1.50D and your left eye approximately -5.00D; that's fairly unusual.  (Changes in your lens due to cataract development wouldn't affect your eye measurements.)  Amazing that you could drive without glasses!

I'm not an eyecare professional, but I believe that those IOL power predictions involve a margin of error in both directions.  And other factors (such as astigmatism) would  affect your visual acuity.  If you have questions/concerns about your post-surgery vision, you should discuss them with your doctor, who is in a position to best advise you about your particular situation.

[hmkim]

Jodie, in some states such as NJ, 20/50 in one eye is all you need to pass the DMV vision test.

[JodieJ]

Your right, hmkim!  Actually, it's only 20/70 in Florida per the internet.  I'm still in the dark as to how sergmick managed with one eye being -1.50D and the other -5.00D without wearing a contact lens in his bad eye; I'd think that a 3.50D difference between his eyes would give him double vision.

[Ag-i-doc]

serg:

sorry...you're right.  the "ref" was  short for "refraction", wasnt it?  it had to be based on what you're saying

okay the explanation is reversed.  -0.25 would be better for DV and the -0.92 would be better for NV

regardless, these numbers houlsnt mean that much to you.  tell the surgeon what you prefer and let them pick the IOL

[sergmick]

Two quotes from the OPTHAMOLIC HYPERGUIDE


"If the patient has binocular cataracts, the decision is much easier because the refractive status of both eyes can be changed. The most important decision is whether the patient prefers to be myopic and read without glasses, or near emmetropic and drive without glasses. In some cases the surgeon and patient may choose the intermediate distance (-1 D) for the best compromise. Targeting for monovision is certainly acceptable, provided the patient has successfully utilized monovision in the past. Trying to produce monovision in a patient who has never experienced this condition may cause intolerable anisometropia and require further surgery.


Desired Postoperative Refraction
For monofocal lenses, surgeons have traditionally been aiming for

[JodieJ]

There's reported to be about a .5D margin of error in each direction of the targeted refraction.  However, corneal astigmatism also affects post-surgery vision.  This type of  astigmatism can generally be reduced with limbal relaxing incisions (or another refractive procedure) at the time of cataract surgery.  But the results of LRIs are supposed to be difficult to predict.  Residual astigmatism could leave you with vision much worse (more nearsighted) than 20/40, even with a targeted refraction of -.59.  To learn more about all this, go to the Google group sci.med.vision and read the thread "choice of near or far vision after surgery?" (9/1/06).  There are some other threads along this line in the group archives, some of which include posts from a practicing cataract surgeon (Dr. Robins).  I think you'll find them interesting.

BTW, although a cataract definitely causes loss of vision, it doesn't affect the eye measurements used by the IOL Master.  It seems VERY unlikely to me that an eye that was 20/40 pre-cataract development would require a lens in power 15.5.  (Maybe that tech gave you the wrong data sheet, or something like that?)