Best laser eye surgery procedures for correcting astigmatism…
Can laser eye surgery help astigmatism? Ask a group of medical students to explain astigmatism to you and nine out of ten of them will struggle to come up with anything that makes sense. It is one of those confusing words that everyone’s heard of and yet many just don’t get. Perhaps the problem lies with the word itself. Astigmatism brings to mind a stigma, and we all know that’s not good. Or perhaps it gets confused with strabismus – the eye condition where the eyes turn in or out and don’t work together. Either way, astigmatism sounds like trouble. But is it?
What is astigmatism?
The eye operates in many ways like an optical instrument – a camera is a popular analogy. It uses lenses to focus light onto the retina. But the eye is also a flesh and blood structure – the organ of sight – and is flexible, not unlike a rubber ball. It is not precision-engineered steel and glass like a camera. Just as most people have one foot a little bigger than the other, most people have one curve of their cornea (the front surface of their eye) a little more curved than the other.
Fact 1: Astigmatism is very common.
This is all astigmatism is. It is simply the difference in curvature between the two contours of the cornea. It is rarely a marked difference – such as we would find in an egg or a rugby ball. It is usually far more subtle than that and is only picked up when measuring the refractive error of the eye during an eye examination. These measurements then form the basis for a pair of glasses to correct your vision.
Fact 2: It is more normal to have some astigmatism than none at all.
Mild-to-moderate levels of astigmatism (up to about -4 dioptres) are very common and straight-forward to correct. The correction can be incorporated into a pair of glasses and most glasses prescriptions contain a correction for astigmatism. It can also be easily incorporated into any corneal laser vision correction procedure – LASIK, SMILE
Contact lenses can also correct astigmatism but it requires an experienced contact lens fitted to get a good fit and consistent vision.
Fact 3: Most astigmatism is mild to moderate and easily corrected with glasses or laser eye surgery.
Larger amounts of astigmatism (over -4 dioptres) are rare and a bit trickier to correct. A correction can still be incorporated into your glasses but it takes a bit of getting used to as it distorts your view of the world, warping it to some degree. Contact lenses are also trickier to fit. And laser eye surgery can treat most of the error but there may be a small residual amount of astigmatism left afterwards. This is something to discuss with your laser vision correction specialist. It is not unusual to be able to eliminate all of your astigmatism, even at moderate-to-high levels, through laser eye surgery, but it is not quite as predictable as with low-to-moderate levels.
Fact 4: Severe astigmatism is rare and can be harder but not impossible to eliminate fully.
What vision correction procedures can correct astigmatism?
LASIK is the most popular laser eye surgery technique for treating a range of spectacle errors including short-sightedness (myopia) and long-sightedness in the approximate ranges +4 to -10 (including astigmatism).
ASLA has a smaller range, from +3 to -8 dioptres of short-sightedness or long-sightedness including astigmatism.
SMILE laser can correct short-sightedness and astigmatism in the range -3 to -10 dioptres and is not currently available for long-sightedness.
Laser lens surgery and implantable lenses can cater for any degree of astigmatism. Full correction depends on accurate placement of the intraocular lens so an experienced, expert surgeon will achieve best results.
In the event that there is still some residual astigmatism after your procedure, this can often be improved with an enhancement procedure. Realistic expectations will be discussed with you before you have any laser eye surgery procedure.
Fact 5: A wide range of laser vision correction procedures can correct astigmatism very successfully.Don't let astigmatism put you off having laser eye surgery to get rid of your glasses.