Position of toric lenses

[TillyMack]

My surgeon suggested and I agreed to have toric lenses implanted. I would be interested to know if these lenses have retained their correct positions at subsequent post op appointments but this information has not been forth coming despite my requests.

Does this require special diagnostics or should this be evident at one week or 6 week post op appointments or even whenever the eye has been dialated?

Alternatively is this question not addressed unless the patient has a complaint regarding visual acuity?

I would appreciate any feedback from group members who have toric lenses.

[Ron_AKA]

The important thing to consider is that the position should  be checked at the 24 hour post surgery exam. At that point the lens position can be adjusted if necessary. The other thing to consider is toric lens is only needed if you want to be eyeglasses free. Astigmatism can be easily corrected and probably more accurately corrected with eyeglasses.

[John C Hagan III, MD, FACS, FAAO]

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[John C Hagan III, MD, FACS, FAAO]

If you do a websearch or medical literature search about 3% of toric lens have to be adjusted post operatively.  If they have not rotated by 2-3 months post operative not likely to rotate due to fibrosis around the edge of the toric lens.  If the toric has rotated and the patient has no complaints few surgeons would intervene, what are you trying to fix and the rotation carries risks. As far as diagnosis: with a dilated pupil the surgeon can see the orientation and second the post operative glasses testing will show significant resideual astigmatism.

[TillyMack]

This eye targeted -1.5 D.  Since my near and intermediate vision seems good, I have no complaints.  That said, I'm not sure what to expect in terms of distance (perhaps beyond 2 ft).  I thought it would be helpful to know if the toric rotated so that I would know if rotating the lens back to the correct position would help my distance vision in this eye.  Does this make sense?

[John C Hagan III, MD, FACS, FAAO]

Your vision will only be in focus at 26 inches. You may have a depth of focus were things are clear within 6 inches either side of that. It's called depth of focus and it comes from the size and reactivity of the pupil and proprietary properties of the IOL. At 20 ft or more things would not be clear unless you are looking through a -1.5 D glasses

[TillyMack]

Thank you.  I have a somewhat related question regarding my other eye which targeted -1.0D.  Comparing the cards I received at the time of surgery, the power of each is 16D and 16.5D.  I see much more with the 16D eye overall.  I had expected the 16.5D eye to provide better near vision than the 16D eye but they seem very similar if not the same.  Does this make sense?
Thanks again.

[TillyMack]

In other words, what does a -1.5D lens offer if the same or almost the same near visual acuity is available with a -1.0D IOL?

[John C Hagan III, MD, FACS, FAAO]

Because the shape, and axial length of each eye is often different even if both eyes are targeted for the same post op refractive error say -1.50 the IOP is over going to be different. If the post op refractive error is -1.00 in one eye and -1.50 in the other the -1 eye could have clearer vision further out and the -1.50 more magnification at a shorter distance from the eyr

[John C Hagan III, MD, FACS, FAAO]

eye

[TillyMack]

To confirm, I'm speaking only of near vision.  In other words, why does a -1.5D lens offer the same near visual acuity as a -1.0D IOL?  Could you address that situation?  Many thanks.

[John C Hagan III, MD, FACS, FAAO]

If an optical bench was used to determine exact focal points then the 1 diopter IOL would be focused at 39 inches and the 1.5 at 26 inches. However because of depth of focus, different health/strength of the eye itself a person might not be able to tell any difference.  Remember eyes very frequently  do not see equally well (e.g. dominant eye, one eye with health problems, etc)

[TillyMack]

Very helpful, thank you!

[John C Hagan III, MD, FACS, FAAO]

Happy to help. MERRY CHRISTMAS