Non-corneal astigmatism?

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The Real Bev - 02 Nov 2007 02:03 GMT

My opththalmologist also fits contacts, so she said she'd look at my
corneas. Average thickness, but most of my astigmatism comes from elsewhere
in the eye. She sounded like it was NOT an easy thing to determine other
astigmatism sources so I asked no further questions. I should have, and I
will when I go back in 6 months or when my current set of lenses dies.

Anybody know what she meant?

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Cheers, Bev
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p.clarkii@gmail.com - 02 Nov 2007 02:17 GMT

> My opththalmologist also fits contacts, so she said she'd look at my
> corneas. Average thickness, but most of my astigmatism comes from elsewhere
[quoted text clipped - 11 lines]
> must spend restarting windows and then determining how many work weeks
> that would correspond to." -- Trygve Lode

really it's impossible to get more precise than she told you. our
current state of technology allows us to discern whether astigmatism
is caused by corneal toricity, or "other non-corneal" causes. the
most likely non-corneal causes are due to changes in the lens such as
equatorial tilting, or possibly misalignment of the optical center of
the lens compared to that of the cornea. your doctor is telling you
the truth, and regardless the treatment is the same.

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Dr Judy - 02 Nov 2007 16:57 GMT

> My opththalmologist also fits contacts, so she said she'd look at my
> corneas. Average thickness, but most of my astigmatism comes from elsewhere
[quoted text clipped - 3 lines]
>
> Anybody know what she meant?

What she meant was that the amount of astigmatism in your glasses is
not the same as the amount on your cornea. There is no easy way to
measure astigmatism from the lens or due to toricity of the back
surface of the cornea or of the retina, so she doesn't know for sure
where the astigmatism is coming from. The lens is the most likely
source.

It means that standard rigid lens won't work and you will need toric
rigid or toric soft lenses.

Judy

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The Real Bev - 03 Nov 2007 23:01 GMT

>> My opththalmologist also fits contacts, so she said she'd look at my
>> corneas. Average thickness, but most of my astigmatism comes from elsewhere
[quoted text clipped - 10 lines]
> where the astigmatism is coming from. The lens is the most likely
> source.

Thanks, that's a good enough explanation. "If it isn't here, we haven't a
clue where else it's coming from." I was envisioning something like a
twisted eyeball.

> It means that standard rigid lens won't work and you will need toric
> rigid or toric soft lenses.

No toric RGPs (I tried 8 sets) worked and most of the toric softies don't
work, even if the trial lens did :-(.

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Cheers, Bev
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"Don't you wish there were a knob on the TV to turn up the
intelligence? There's one marked "brightness", but it
doesn't work." -- Gallagher

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The Real Bev - 03 Nov 2007 23:03 GMT

>>> My opththalmologist also fits contacts, so she said she'd look at my
>>> corneas. Average thickness, but most of my astigmatism comes from elsewhere
[quoted text clipped - 20 lines]
> No toric RGPs (I tried 8 sets) worked and most of the toric softies don't
> work, even if the trial lens did :-(.

Rats, I didn't finish... She said my corneas were of average thickness, so
that probably means that lasik is probably out of the question because they
would have to add compensatory correction instead of just smoothing it out.
Right?

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spammer - 04 Nov 2007 01:14 GMT

> Rats, I didn't finish... She said my corneas were of average thickness, so
> that probably means that lasik is probably out of the question because they
> would have to add compensatory correction instead of just smoothing it out.
> Right?

Not necessarily, there's always epi-lasik or PRK. Either one would
leave you with plenty of cornea.

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Dr Judy - 04 Nov 2007 16:27 GMT

> >>> My opththalmologist also fits contacts, so she said she'd look at my
> >>> corneas. Average thickness, but most of my astigmatism comes from elsewhere
[quoted text clipped - 24 lines]
> that probably means that lasik is probably out of the question because they
> would have to add compensatory correction instead of just smoothing it out.

Not sure what you mean by add correction -- are you hyperopic?

LASIK can correct non corneal astigmatism, if that is what you are
asking. Whether or not your average thickness cornea is thick enough
for LASIK depends upon the exact thickness, pupil size, your exact
prescription, whether custom abalation is needed, laser used, and the
type of surgery (LASIK, LASEK, PRK ....). A laser centre will be able
to tell you and initial consults are often free.

Judy

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The Real Bev - 05 Nov 2007 05:37 GMT

>> >>> My opththalmologist also fits contacts, so she said she'd look at my
>> >>> corneas. Average thickness, but most of my astigmatism comes from elsewhere
[quoted text clipped - 26 lines]
>
> Not sure what you mean by add correction -- are you hyperopic?

Yeah. I meant that the cornea would have to be carved to counteract
whatever was causing the rest of the astigmatism instead of just being
nicely smoothed out. Nothing is ever simple.

> LASIK can correct non corneal astigmatism, if that is what you are
> asking. Whether or not your average thickness cornea is thick enough
> for LASIK depends upon the exact thickness, pupil size, your exact
> prescription, whether custom abalation is needed, laser used, and the
> type of surgery (LASIK, LASEK, PRK ....). A laser centre will be able
> to tell you and initial consults are often free.

I'm satisfied with my ophthalmologist -- she frowned and said "That's
something else entirely..." which sounds like a negative opinion to me. I'm
not thinking about it seriously, just as a back-of-my-mind possibility.

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Cheers, Bev
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If it doesn't move and it should, use WD-40.
If it moves and shouldn't, use duct tape.

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