Cataract Procedures
Phacoemulsification
Phacoemulsification is a surgical method used to remove a cataract, which is a clouding of the eye’s naturally clear lens. A cloudy lens interferes with light passing through to the retina, the light-sensing layer of cells at the back of the eye. Having a cataract can be compared to looking at the world through a foggy window.
In phacoemulsification an ultrasonic oscillating probe is inserted into the eye. The technology is similar to the ultrasound the dentist uses to clean your teeth (the inventor of phacoemulsification came up with the idea while sitting in the dentist chair!). The probe breaks up the hard center of the lens. The fragments are suctioned from the eye as they're created. This allows for a small incision that does not require sutures to be used Most of the lens capsule, the membrane around the lens, is left behind and a foldable intraocular lens (IOL) is implanted permanently within the membrane to help focus light onto the retina. Vision returns quickly, and one can resume normal activities within a short period of time.
Posterior Capsulotomy
A posterior capsulotomy is a laser procedure that sometimes is necessary after cataract surgery.
During cataract surgery, part of the front (anterior) capsule of the eye’s natural lens is removed to gain access to and remove the lens. The clear, back (posterior) capsule remains intact and supports an intraocular lens (IOL), a plastic or silicone disc that is implanted in the eye and replaces the natural lens. As long as that capsule stays clear, you will experience good vision. But in 10% to 30% of cases, the posterior capsule loses its clarity, blurring the vision. When this happens, the ophthalmologist (Eye M.D.) can create an opening in the capsule with a laser. This procedure is called a posterior capsulotomy.
Before the laser procedure, the ophthalmologist does a thorough ophthalmic examination to make sure there is no other reason for vision loss.
The posterior capsulotomy is painless and takes approximately five minutes. Anti-inflammatory medicated eye drops are usually prescribed for a few days following the procedure. Vision usually improves within hours.
Potential but rare complications following laser posterior capsulotomy are increased intraocular pressure and retinal detachment. Our eye care practice welcomes you to contact us for a consultation or complete eye health examination. We provide excellent patient education and describe the entire process from start to finish.
Your Glasses Prescription After Cataract Surgery
In doing cataract surgery, your natural lens is replaced by an artificial lens, the “intraocular lens implant” (IOL). That lens can be any power that we want it to be. That gives us a lot of options. We can eliminate or reduce, or even induce, nearsightedness, farsightedness, astigmatism and presbyopia (that trouble we have with focusing up close after age 42 or so). See the “Intraocular Lens” section for more information and options. Here are some other things to think about. If all this seems confusing or to be too much information, don’t worry. We will be happy to discuss a good option for you.
For patients having surgery on only one eye:
Normally, we put that eye in focus naked eye at distance. If your other eye is already in focus naked eye for distance, you can opt for making the operated eye a bit nearsighted. That way, that eye will be in focus at a computer distance or for near, reducing or eliminating the need for glasses. (See modified monovision and monovision, below.)
If you have a lot of far- or nearsightedness in the other, non-operated eye, we will have to leave you with some far- or nearsightedness in the operated eye. That is because if you need a strong glasses’ lens for the non-operated eye and a minimally powered lens for the operated one, the two eyes would not be able to work together, and you would see double. The glasses’ prescription for the two eyes has to be in the same ballpark
For patients having surgery on both eyes:
Now you have more options.
1. The commonest arrangement is to make the dominant eye in focus for distance and the non-dominant one for intermediate range (such as computer or store shelves). This is a nice option, because it makes you relatively independent of glasses. Most people still need reading glasses for prolonged reading or fine print. These can be prescription readers or over-the-counter readers, depending on need. This is called modified monovision.
2. Full monovision is similar to modified mono, except the non-dominant eye has a full near correction. We only recommend this if you know that you like this from having worn full monovision in contact lenses.
3. Multifocal lenses have concentric rings that allow near and distance, with the centre in focus for near. The brain adapts to which image to pay attention to, depending on the task at hand. This lens gives you the best chance of being totally free of needing glasses. However, it virtually always causes some halos around lights at night and can cause other compromises to the quality of your vision. The best candidates for this lens are those that really value being totally glasses-free and are willing to tolerate some compromises in vision quality to achieve that. Amongst such people, this lens has a high success rate. There is a considerable out-of-pocket cost. See the “Intraocular Lens” section for more information.
Correcting Astigmatism
What is astigmatism, you ask? The cornea, the clear dome in the front part of the eye, is ideally spherical. When the cornea is more curved along one axis than another, like a football is, that's astigmatism. Your astigmatism is being corrected now by either glasses or contact lenses. If we correct your astigmatism at the time of cataract surgery, you will be able to see better without glasses. If we don’t correct it, you will need glasses or a contact lens to see properly, as you do now.
If you have significant astigmatism, a Toric implant can give you good naked-eye vision, maybe for the first time in your life! Like a conventional implant, a toric implant's focal distance is set to where you would like it to be -- distance, near or in-between. Most patients opt for naked-eye distance vision in the dominant eye and at approximately computer distance for the non-dominant one. There is an out-of-pocket charge for the toric IOL.
If you don’t have a lot of astigmatism, you can opt for limbal relaxing incisions. This consists of a partial-thickness groove made in the very periphery of the cornea. It will not affect the care or restrictions after the surgery. The results are much less predictable than those with a toric implant, and LRIs are suitable for patients with only a modest amount of astigmatism. There is no out-of-pocket charge for LRIs.
If you have only a little astigmatism, it is to your advantage to leave it uncorrected. A little astigmatism helps with your depth of focus and so can be helpful, especially in cases of modified monovision.
Important!
The technology we have today of determining your prescription after surgery is good, but it is not perfect. Sometimes patients become a little more near- or far-sighted than intended. Rarely, it is a lot more. In these cases, patients may be more dependent on glasses than hoped, but the quality of vision, with glasses, is unaffected. If this is a really big problem for the patient, it can be corrected by either replacing the implant with another one, slipping a thin implant over the existing one, wearing a contact lens or having excimer laser surgery, such as LASIK.