Astigmatism is a condition that causes blurred vision and is usually caused by an irregularly shaped cornea (the clear front part of the eye). Astigmatism is correctable through the use of eyeglasses or contact lenses. If astigmatism isn’t corrected by these means, the result is blurry vision at all distances.
A toric intraocular lens is a special lens that corrects for corneal astigmatism in order to provide clearer uncorrected distance vision after cataract surgery.
Presbyopia is a condition that causes a decreased and eventual loss of the ability to focus up close. It is a normal part of aging that usually starts to occur in our mid to late forties.
This is a special intraocular lens that attempts to decrease your dependence on glasses at all distances: near, intermediate, and distance.
Most patients are able to decrease their dependence on glasses after implantation of a presbyopic intraocular lens. However, some patients may find that they may still require eyeglasses for certain visual tasks, i.e. while working on the computer (visual tasks requiring intermediate vision) or while doing very fine, detailed work.
There are a few different kinds of presbyopic lenses that Dr. Kim can implant into your eye during cataract surgery. Each lens has its own unique side effect profile. For some of the presbyopic lenses, a certain percentage of patients may experience symptoms of glare and halos around lights. These will usually diminish with time but in rare cases will persist. Some patients may also notice a slight decrease in the quality of their vision. Most patients accept this as a reasonable ‘tradeoff’ for decreasing their dependence on eyeglasses.
If you dislike the idea of always having to wear eyeglasses for your near and intermediate visual tasks, you may benefit from one of these lenses. Certain diseases or conditions of the eye may preclude you from being a candidate for these lenses.
The standard intraocular lens is a monofocal lens, meaning that it will correct for only one focal distance (usually distance focus). It also does not correct for astigmatism. You will need to wear eyeglasses to help you focus your eyes at the other distances (usually near and intermediate). Eyeglasses for clear distance vision will also be necessary if you have a significant amount of astigmatism.
Cataract surgery involving the use of the upgraded intraocular lenses is very similar to standard cataract surgery with a few but important exceptions. For placement of a toric intraocular lens, the axis of your astigmatism must be marked on your eye immediately before and during your cataract surgery. The toric intraocular lens must also be exactly positioned at the conclusion of your cataract surgery in order to work properly. In addition, if your astigmatism is greater than what the toric lens can correct for, additional surgery may be performed on the surface of your cornea (called peripheral relaxing incisions) during or after the cataract surgery. For the presbyopic intraocular lenses, any pre-existing corneal astigmatism must be reduced via peripheral relaxing incisions in order to maximize the benefits of this lens. These peripheral relaxing incisions will be done either at the same time as or after your cataract surgery.
Your medical insurance will only cover standard cataract surgery. The upgraded intraocular lenses and the work and evaluation required to place either a toric intraocular lens or a presbyopic lens is not covered by medical insurance. This means that you will be financially responsible for the added costs (you will have to pay ‘out of pocket’ for these additional expenses).