What Form Of Astigmatism Requires Correction?
I recently had cataract surgery and the AcrySof Toric IOL implanted in one eye. At the first checkup, my vision was:
SPH: +1.25
CYL: Nil
AXIS: Nil
Just 2 days ago, my follow up revealed the following
SPH: +1.00
CYL: -0.50
AXIS: 160
Q: During this period, I developed about -0.50 D of astigmatism. What are the chances of my Astig progressing until I’ll be needing astigmatic correction in the future?
Q: I hear from my surgeon that some form of astigmatism can be beneficial for my overall vision. What qualify it as “beneficial astigmatism”?
Q: It is believed that mild level of astigmatism does not warrant correction. What range is considered as “mild”? Will my current level of astigmatism require vision correction?
Q: My concern is since my IOL is a toric lens, initial tests showed that it corrected 100% of my astigmatism. The sudden appearance of -0.50 D of Astig, may mean the IOL is rotating inside my eye, thus negating any correction by the IOL? How likely is that the case?
Tags: Astigmatism, correction, Form, requires
September 2nd, 2010 at 4:01 pm
In order, more or less…
Note that your overall Rx has improved in that period:
Mean sphere from +1.25 to + 0.75. You may well be still in the healing period. It’s looking like an excellent result.
The astigmatism component may increase or disappear in the next month or so. I wouldn’t expect it to change massively. Anyway, it can easily shift 0.25 from visit to visit just by observation and operator variation.
Beneficial astigmatism? Sounds more lke reassuring flannel, or B.S.
Some people with appreciable astigmatism find they can use the reduced best vision over a range of distances. Most would rather have the better v ision.
Not as bad a saying a man with wooden legs saves on socks but it’s in the same category.
As far as “What level…” that’s personal. And nothing unique to astigmatism… Does that +1.00 sphere need correcting?
It depends on what you’re doing, how much blur or fatigue you’re noticing, and how you feel about that.
Some people will put up with almost any amount of missing Rx, including astigmatism rather than “Wear glasses”
Some people will wear the smallest Rx rather than “Have Blurred Vision”.
Provided you’re legal driving, the rest is up to you, with no medical consequences.
The additional “push” in astigmatism is that toric contacts cost more, so the temptation is to “let the astigmatism go” to save money, especially when it’s around 0.75.
Rotation in the implant is extremely unlikely.
“The sudden appearance of -0.50 D of Astig,… ” means little or nothing, I”m afraid. It’s too small an error at too early a stage.
I wouldn’t be surprised at a Rx that took three months to stabilise, though it’s nearly always finished changing in half that.
Optometrist, retired.