Can cataract surgery fix Astigmatism?

Of course cataract surgery can correct your astigmatism! Nowadays with the advent of technologically advanced toric intraocular lens implants, I always take the opportunity to correct all my patients' astigmatism during cataract surgery.

Not only do I correct astigmatism, I also take the opportunity to correct my patients' residual powers to allow them to be as spectacle-independent as possible! I believe that cataract surgery is a great opportunity to correct your eye degree to best suit your lifestyle so that you can function well without spectacles for the majority of the time!

Astigmatic correction does require high precision and great care on the part of your eye doctor, so do have a good chat with your eye doctor about how he/she can best help you resolve your astigmatism completely!

Hope that helps!

Dr Claudine Pang

Hi Ashley

Yes, indeed astigmatism can be fixed during cataract surgery. Cataract surgery is nowadays a form of refractive surgery, where we take the opportunity to correct longsight, shortsight as well as astigmatism at the same time.

Taking a step back, longsight, shortsight and astigmatism are all 'refractive errors' or focusing issues of the eye. When surgeons perform cataract surgery, we are removing an old hazy lens and replacing it with a new one. This new lens can be customised to the particular patients' eye so that we can provide a post-operative spectacle power desired by the patient.

In an eye, there are mainly 2 parts that focus light-the cornea and the lens.

Astigmatism usually arises from an irregularity of the shape of the cornea, and to a lesser extent the lens. The irregularity is because in one direction, there is a more curved or rounder surface, and in the other direction, there is a flatter surface. Kind of like a rugby ball.

Since we remove the lens (which is the cataract) during surgery, the only source of astigmatism remaining afterwards would be the cornea. Therefore, to reduce astigmatism after surgery, we can choose a new 'toric' lens implant that will cancel out the astigmatism of the cornea.

Low degrees of corneal astigmatism less than about 50-75 degrees do not need correcting usually, because it does not blur vision much at all. Higher degrees can be corrected very well with the special toric lens implants.

Other methods that can be used to reduce or correct astigmatism include special cuts on the cornea called relaxing incisions, but these are rarely used nowadays because they are much less accurate than toric lens implants.

Laser surgeries such as LASIK are also possible to correct astigmatism but in the context of cataract surgery, can only be done once the eye has healed from the original cataract surgery, about 3 months after the original operation.

During cataract surgery, it is indeed possible to correct astigmatism at the same time. The astigmatism correctable is the astigmatism that arises from the cornea, and this may be different from what you actually wear in your glasses or contacts.

There are a few ways astigmatism can be corrected at the setting of a cataract surgery:

1) Sometimes, if the astigmatism power is low and astigmatism's direction is where the small incision for cataract surgery is, nothing else needs to be done. The usual cataract incision can already treat the low astigmatism.

2) Choosing a lens implant (IOL) that incorporates astigmatism treatment: these are called toric IOLs. This can be in the form of either a monofocal or multifocal IOL.

To determine whether your astigmatism can be satisfactorily corrected by an IOL, you can undergo a careful test of your cornea curvature while measuring for the IOL, such as using a device (like the Galilei G6 which I first introduced in Singapore in 2016). This will show if your astigmatism is regular or irregular. Correction of regular astigmatism with IOL is more predictable than correction of irregular astigmatism with IOL.

3) Many years ago, before the toric IOL became available, eye surgeons including myself used a precise blade (a diamond blade) to make cuts on the sides of the cornea in a procedure called "LRI" (limbal relaxing incision) to treat astigmatism during cataract surgery. This has become less popular compared to the toric IOL as the LRI is less predictable and patients may get longer periods of side effects like dry eyes and irritation after surgery.

Having said all that, I had also treated patients who did not manage to get their astigmatism treated at the time of cataract surgery, due to reasons such as not being able to afford the more expensive IOL. Laser vision correction such as LASIK, advanced surface ablation and also RELEX SMILE can certainly treat low to moderate astigmatism very well, as a separate procedure. This can be done several months after the cataract surgery.

High astigmatism such as above 300 degree, however, is best corrected by toric IOL.

I wish you a successful cataract surgery!

Cheerio

Dr Daphne Han

D2D. Yes. Over the years, many different surgical techniques have been employed to correct astigmatism during cataract surgery.

Current intraocular lens technology corrects low to high astigmatism with much precision using Toric (astigmatic) intraocular lenses. In order to place these lenses accurately, we use advanced technologies and the latest equipment at our centre to map out the curvature of the cornea and measure the astigmatism of the eye.

These measurements enable the precise placement of the lens in the correct axis and thus reduces the astigmatic power of the eye. Many patients have benefited from these technologies, resulting in independence from astigmatic spectacles for distance and near vision.

In a word yes. It is possible to correct astigmatism and in addition, myopia and presbyopia with a multifocal toric intraocular lens (IOL). The result of which you may potentially gain spectacles independence.

Thought it is important to have a detailed evaluation of your eyes as not every patient is suitable to go for the multifocal toric IOL.

Sorry to hear about your upcoming surgery. Although the fear of upcoming surgery can be daunting, you can indeed look forward to correction of your ocular astigmatism during the procedure. This is performed with implantation of a toric intraocular lens that will correct the total astigmatism of the eye.

Prior to the surgery, extensive investigations are performed in order to get accurate measurements of all relevant aspects of your eye. Advanced lens formulas are utilised in order to determine the best intraocular lens to place in your eye.

Correct orientation of the lens is extremely important, and your surgeon may recommend several adjuncts to your surgery that may theoretically improve the positioning of the lens including the performance of femto-laser assisted cataract surgery. In rare instances (usually less than 5%), the lens may need some minor adjustment to get the optimum position for correction of your astigmatism.

Best of luck with your surgery!

ESG