What is a Cataract?
A cataract is a slow, progressive clouding of the eye's natural lens. It interferes with light passing through the eye to the retina. Cataracts are caused by a change in the proteins of the eye, which causes clouding or discoloration of the lens. Over time cataracts typically result in blurred or fuzzy vision and sensitivity to light.
People with cataracts often describe the sensation as looking through a piece of wax paper. A cataract may make light from the sun or a lamp seem too bright, causing glare. Colors may not appear as bright as they once did, however, most cataracts develop so slowly that people usually don’t realize that their color vision has markedly deteriorated. Oncoming headlights may cause uncomfortable glare at night, making driving more difficult. There is a myth that cataracts have to “ripen’, before they can be removed. This was true before about 1930, when the surgical technique to remove cataracts was quite primitive and the surgical outcome was essentially awful, even in uncomplicated cases. Patients had to be blind from their cataract before surgery, so they could appreciate the often limited improvement in their vision after surgery. These days, when most cataract patients see much better after surgery, we wait until the patient finds that the cataract is interfering with their lifestyle. Patients often have cataract surgery when they are having difficulty seeing the golf ball, reading the financial pages, or driving at night. The most common response on the day after surgery is, “When can I have the other eye done?” followed by “Why did I wait so long?”
Causes of Cataracts
Using the most up to date methods and instrumentation, cataract surgery is typically performed using a small incision phacoemulsification technique. This means that the cataract surgery is accomplished using the smallest possible incision, and removal of the lens material is accomplished using an ultrasonic probe.
There is a common misconception that cataract surgery is done using a laser. This is not the case, and has never been the case. The use of laser energy produces too much heat to be adapted for this purpose, and would cause irreversible damage to the delicate tissues inside the eye.
Following proper dilation of the pupil and preparation of the surgical area using betadine or other cleansers, a topical anesthetic is administered to the surface of the eye, or a local anesthetic can be applied. An incision of 2.5 to 3 millimeters in length is then created at the junction of the cornea (the clear domed structure on the front of the eye) and the sclera (the white part of the eye).
The eye is then entered and filled with a viscous material. The front part of the lens envelope, know as the lens capsule, is carefully opened so that the lens material can be removed. This is accomplished using a pen-like ultrasonic device, which pulverizes the hardened and yellowed lens proteins. The pulverized material is simultaneously vacuumed from the eye.
Once all of the cataract material has been removed, and assuming that the lens capsule which was opened at the beginning of the surgery remains strong enough to support the lens implant, a folded intraocular lens is inserted into the lens capsule and centered. If the capsular support has been compromised then an alternative lens will be placed in the eye. This happens in less than 1% of surgical cases. The lens will remain inside your eye in this location without moving. Intraocular lenses cannot be felt or sensed by the patient. After surgery the cataract cannot return.
In most cases, once the lens is centered within the lens capsule, the instruments are removed, and the surgery is therefore complete. Under most normal circumstances stitches (or sutures) are not required to keep the incision sealed. Should the incision require a suture to be placed for proper sealing, this suture is generally removed the day following surgery.
Recovery from surgery is generally very quick, with most patients achieving noticeably better vision within the first 24 hours of the procedure. Patients are generally asked to use three different eye medications, administered as drops several times daily for the first few weeks after surgery. It is important that during the first 7 post-operative days patients refrain from strenuous activity such as lifting weights for exercise or lifting other heavy objects. Patients should also refrain from eye rubbing during the first few weeks following surgery.
If glasses are required following surgery to achieve the best possible vision either for close up work such as reading, or for distance purposes, these will be prescribed three to four weeks after surgery when full recovery is expected. If both eyes are scheduled to have surgery within a few weeks of each other, then glasses, if needed, will be prescribed approximately one week following surgery of the second eye.
There are risks with cataract surgery. More than 99% of cataract surgery is uncomplicated. The most significant risks include infection, bleeding, and retinal detachment. The incidence of these events is less than 0.001%. If one of theses events occurs they often can be treated. Rarely, any of these events can cause one to lose all of the vision in the eye.
Intraocular Lens Options
Intraocular lens come in a variety of materials and designs. Your surgeon generally chooses a lens made of a material that is best suited to your individual situation. All intraocular lenses used in our practice are coated with UV filters. Some lenses are yellow in color. These lenses are theoretically better at blocking the light rays in the blue spectrum which are thought to be related to the development of macular degeneration. Some intraocular lenses are designed to be multifocal in certain lighting circumstances, which may enable patients to see both at distance and near without the aid of spectacles. This effect has been shown in all patients in whom the lens has been implanted, and it is once again important for patients to realize that while cataract surgery with intraocular lens implantation frequently results in a reduced dependency on eye glasses it is never guaranteed to eliminate this need totally. More information about cataract surgery.