Toric in one eye, multifocal in the other?

Does anyone ever prescribe that combination? Does it make any sense?
Or--does it only make sense to use multifocal lenses if in both eyes?

I'll explain why I'm asking this, and hope that the helpful eye
professionals here will give their opinion.

I have always been very nearsighted. I wore RGP lenses for many years. In
the last few years though, I've come to like the comfort and convenience of
silicon hydrogel soft lenses, wearing them overnight. Even if the vision is
not quite as clear, to me the comfort and convenience is a good trade-off. I
have been wearing Focus Night&Day for about five years now, monovision.
(Currently 55, becoming increasingly presbyopic.)

My prescription has remained stable for those years-Right -5.25 (distance),
Left -4.5 (near). (BC 8.4 both eyes) I can get by with that Rx, passed the
driving test last time, drive in them, etc., but I have noticed that my
distance vision leaves a lot to be desired, although I can get by. (And I
realize that presbyopic solutions such as monovision and multifocals always
involves compromise, lessening of distance vision in order to have near
vision without reading glasses.) (My left eye is actually more nearsighted
than my right--so that 4.5 rx left is undercorrected a lot for near vision.)

At my recent eye exam the O.D. recommended a toric lens for my right eye.
(I'm actually surprised that that hadn't been recommended to me earlier,
since I had started with soft lenses, since I do have some astigmatism.) He
said there wasn't enough astigmatism in my left eye to warrant a toric lens,
but there was in my right eye. He gave me an Acuvue Advance Toric to try out
in the right eye, also -5.25, with a cylinder of .75, bc 8.6. I kept the
N&D -4.5 in my left eye.

I immediately noticed a significant improvement in my distance version, and
did wonder why the toric lens hadn't been suggested to me in other years.

After reading here that the Advance is not rated for overnight wear, and has
a lower dK than the Purevision Toric (see recent thread about silicon
hydrogel torics), I asked my doc to try a Purevision Toric. As I was also
curious about the new Biofinity lens, having read about it here, I requested
a Biofinity lens to try for my left eye. I picked up these lenses yesterday,
and first put them on today. The Purevision Toric is the same RX as the
Acuvue, with the bc being 8.7, and the biofinity is the same RX as the N&D
(-4.5), with a bc of 8.6.

Comments on these--comfort--both lenses are comfortable, but so far I
haven't noticed a difference from the lenses I was wearing before. (I
haven't yet slept in them though.) Vision--I notice still clearer distance
vision with the Purevision than with the Advance. Yet, I notice a decrease
in near vision. Even the letters on the computer screen are not as clear as
usual. I don't know if that difference could be attributed to the PV Toric
in my right eye, or the Biofinity rather than N&D in my left.

The myopia correction in the right eye is the same as before (-5.25). Does
the addition of the toric astigmatism correction negatively affect near
vision? Is there any reason why a Biofinity lens in the left (close vision)
eye could create worse near vision than a N&D lens with the same
prescription?

So--although I like the improvement in distance vision, I don't like the
decrease in near vision. I realize that presbyopic prescribing is a
compromise, and it's impossible to get perfect vision far and near with the
same lenses. But--of course I'd like to get it as good as possible. I'm
wondering whether to suggest any other lens combinations to the OD, for me
to try out?

One possibility occurred to me--which I don't know if it is a good idea--but
I'll ask about it here first. That is, to keep the Purevision toric in the
right eye, and try a Purevision multifocal in the left eye. Does that make
any sense--to have a toric single-vision lens in the dominant eye for
distance, and a multifocal lens in the weaker eye? Is there any advantage to
having the same brand in both eyes, even if one is toric and the other
multifocal? (I think it could be advantageous economically, as there are
often rebates for buying multiple boxes of the same brand.)

I should mention that I tried the Purevision Multifocal in both eyes last
year, and decided not to stick with them, and I kept with the N&D
monovision. Theoretically I like the idea of multifocals much better than
the idea of monovision. The vision wasn't bad with them, but I didn't see
much benefit over the monovision n&ds I was used to, thought they (pv)were
slightly less comfortable, so stuck with N&D. The first trial pair of the
multifocals that the doc gave me, although high add, gave improved distance
vision, but much worse near vision. So, he kept trying a lower distance
power in the left eye (modified monovision), to improve the near vision.
When it went down to -4.75 left, almost as low a distance power in that eye
as I have with straight monovision, and my near vision was still not as
good, I decided to stick with N&Ds.

This year though, in switching to the Purevision Toric in my right eye, I'm
wondering whether it might be good idea to try the PV multifocal in my left,
and see how the two work together. (Again, the left would still need to be
undercorrected for distance, as the "add" created by the multifocal aspect
is apparently not enough to give me usable near vision. But I'm wondering if
it still might be worth trying a multifocal in that eye.)

Before I ask my OD about this, I am curious to hear the opinions of the
helpful eye docs who write here. Is that a feasible idea--a toric in the
dominant, but more astigmatic eye, and a multifocal in the weaker, more
nearsighted eye, for a myopic presbyopic astigmatic patient, 55 years old?

 

0.75D of astigmatism is marginal. Personally, I do like to use it in
patients who are fit for monovision because every little bit of acuity
I can squeak out of their distance eye is worth it (to me) since that
eye is working all by itself in the distance. So docs would simply
ignor it, which would leave you "slightly" blurry by comparison. Some
patients would notice it and like it, some patients wouldn't.

I don't know either. Your doc could probably figure it out. Your PV
Toric lens might be slightly rotated while the AV Adv. Atig. wasn't so
that might explain it. It takes an office visit to know for sure.

Quite possibly. Uncorrected astigmatism can help a little bit seeing
near things. Correcting it would improve distance but hurt near.

Unfortunately I have no experience fitting Biofinity yet. It has only
been released on a very limited basis in the US so far.

You understand the most important point-- you can't get perfect, only
"good enough".

Yes, you should try a lower lens power in your near eye to improve
near VA, or as you suggest, try a multifocal lens in your near eye to
boost your near power.

Sure it does. Its quite logical. There is no "rule" that says both
eyes must have the same brand.

The only advantage would be the economic one you indicate. Otherwise,
just wear what works the best.

I too find the HIGH add powers in the B&L lenses (Purevision and
Soflens Multifocals) to be distorting and not very useful but some of
my patients like them. Everyone is different.

It will just give you a little extra "boost" at near. Otherwise,
there is no reason to wear the same brand in each eye (except for the
rebate issue you mentioned earlier).

 

Thanks for all the info, P. Clark. I'd be interested in hearing other's
input as well. I have one question regarding your statement below, and a
couple other questions:

The Advance was inserted while I was in the doctor's office, and he looked
at it in my eye, and said it sat very well. I picked up the PV in his office
and put it on at home the next day. So true, the doctor hasn't yet seen how
the PV toric sits on that eye, and I'm sure he will want to see it before
prescribing that lens. (Do different brands of torics sit on the eye
differently?) As I said though, the distance vision is very good with the PV
lens so far, I think even better than with the Advance lens. And it is
comfortable. If the lens wasn't sitting correctly on the eye, would I have
good distance vision, and a comfortable fit?

Is the Biofinity spheric? Could that explain the difference in near vision,
switching from an aspheric N&D on the near vision eye, to a spheric lens? (I
may try switching the left eye back to N&D, while keeping the PV toric in
the right, and see if that improves near vision.) (I don't think I will keep
Biofinity in the left in any case. It is advertised as being much more
comfortable, but so far (including overnight now) I don't notice any comfort
improvement over the other si-hy lenses I have worn. And as you write, it is
not very available now. Online distributors don't even carry them. They are
probably extremely expensive, even compared to N&D. It took almost two weeks
for the trial lens to come to the O.D.'s office, which usually takes one
day. Strangely enough, on the case the trial lens came in, the word
"Biofinity" doesn't appear on the label at all. It says SiH 48 (comfilcon
A).)

I don't know about reducing the power on the left eye to even less
than -4.5. At that power, there is already a great difference between the
eyes. (Why I like the idea of multifocals better. If only they worked as
advertised!) The left eye's distance vision is already very weak at that
power. Perhaps just a change to -4.5 multifocal on that eye, instead of
single vision, would make enough difference in improving near vision,
without significantly impairing distance vision. Or--do you think it also
might be worthwhile to try scaling back the right eye to -5 toric, instead
of -5.25?

Of course I will have to discuss these options with my eye doc. Just curious
to hear other's opinions here. (I can see that prescribing for presbyopic
patients is a complicated art.) (Wouldn't it be nice if some day they
invented multifocal lenses that really gave all presbyopic patients good
near, far, and intermediate vision, with no need for monovision? I wonder if
that will come to pass, in my lifetime?)

 

I already switched the left lens back to the N&D, from the Biofinity. Both
the same RX, -4.5. It's amazing what a difference that makes. The distance
vision in the left eye is noticeably worse with the N&D, while the near
vision is better. A significant difference, really.

Could that difference just be caused by aspheric/spheric? Or, does -4.5 mean
something different to Ciba than to Coopervision? Do they sometimes put the
wrong strength in the container? This N&D lens seems definitely weaker (in
minus strength) than the Biofinity lens with the same number (good for near
vision, bad for distance).

I'd still like to improve the near vision a bit more though, depending on
how much that compromises distance vision. I might see about changing the
right eye to -5.00 toric, instead of -5.25, and/or changing the left lens to
a PV multifocal.

Still curious to hear more opinions on these options......

 

Bioinfinity is aspheric as well. The long wait to get the trial lens
is likely because the lens has just been launched with limited
distribution. I'm getting my trial set next week, for 350 offices my
rep is only getting 20 fitting sets. No two lenses will fit the
same. Also the aspheric design will be different in the two lenses
and may be allowing better near with the N&D. B&L has the
"Occasions" multifocal a number of years ago which wasn't really a
multifocal at all. It was an aspheric with the aspheric design such
that the edge of the lens had a touch more plus power.

Using a distance lens in one eye and a multifocal in the other is not
a new idea. Works for some, not for others. I have found that some
monovision patients do not like the loss of contrast inherent to any
soft multifocal. If you didn't like your near vision with PVMF last
year, I wouldn't expect you to like it this year.

Dr Judy

 

Thanks for the info, Dr. Judy!

What about the idea of trying a slightly lesser power in the distance eye
(-5.00 instead of -5.25, yet still toric), to see if that makes a little
improvement in near vision? Is that sometimes done? (That would mean less
disparity between the two eyes.)

 

You really need to work this out with your doctor. Anything can be
done and over the years I have provided patients with most of the
options you have discussed. Whether it works for you depends on you,
just because someone else tolerated it doesn't mean you will.

The best distance and near vision is delivered with distance contacts
on both eyes (toric if needed) and reading glasses over. If you want
to eliminate the readers, then a compromise must be made -- distance
clarity, near clarity, a litte of both, loss of contrast, reduced
depth perception. It all depends on which compromise you, personally,
with your lifestyle and visual demands, can tolerate.

Dr Judy

 

Just spoke to the O.D. on the phone. I told him I would like to try the
Purevision Multifocal in the left, to see if that improves my near vision,
without sacrificing too much from distance.

He didn't like the idea at all, said my distance vision would be too much
worse with a multifocal lens in the left eye.

I brought up my other idea, of scaling back the -5.25 prescription in the
right (distance) eye to -5.0, to improve my near vision. He thought that was
feasible, that it would make the distance vision slightly less clear, and
improve near vision slightly, that it might be a good compromise.

I asked to get a trial lens of the Purevision toric in -5.0. He didn't want
to order a trial for me, said he was sure it would work, just wanted to
order me a box of them. I said I would prefer to try it first, he wouldn't
order a trial lens first for me. So, I said I would think about it and call
him back.

One thing for sure--next year, I think I'll go to a different eye doctor.
(This is the same doc who told me that Advance had a much higher dK than
Purevision, which is backwards.)