A cataract is a clouding of the natural lens inside your eye. This lens, located behind the iris, works just like the lens of a camera, focusing light images on the film of the eye, referred to as the retina, which sends images to the brain. The most common reason for the development of a cataract is aging. The onset is typically very slow, in some cases leaving people uncertain about how much quality of vision they have lost. Cataracts can develop in young people as well, and are sometimes the result of injury, inflammation, or exposure to certain medications. A cataract is not a “film” over the eye and cannot be relieved with medication, eyeglasses, or diet modification.
When vision impairment from cataract becomes noticeable, surgery to remove the lens and replace it with a new man-made lens, called an implant, is necessary. The quality of modern cataract surgery has improved dramatically over the past thirty years, and today the surgery offers fast visual rehabilitation after a brief, minimally invasive procedure. The cataract removal procedure commonly involves a technique called phacoemulsification. This method of breaking up the natural lens inside the eye with sound wave energy permits a smaller incision and faster recovery. The small incision made in modern cataract surgery has many advantages over larger incisions made by cataract surgeons years ago. The vision recovers more rapidly, with much less change in astigmatism. Properly crafted small incisions do not require a suture closure, and can be left “sutureless.” This means there will not be stitches to remove or cause problems after surgery.
The cataract removal procedure is performed in the sterile environment of an operating room to lessen the chance of infection. It is generally an outpatient procedure with no stay in the hospital required. Surgery may take between fifteen and forty-five minutes depending on the complexity of the case. Topical anesthesia (eye drops to numb the eye) is routinely used in combination with sedation given through an intravenous line by an anesthesiologist. This combination is totally effective in relieving pain and anxiety for almost all patients. General anesthesia can be used for patients who are unable to cooperate or who have severe anxiety.
Patients leave the operating room with a clear plastic cover secured over their eye for protection. Medication in the form of eye drops is generally started the same day and is continued for a month after surgery. All patients are examined the day after their surgery and about a week later. These visits are to screen for infection, unusual inflammation, or eye pressure elevation. A month after surgery, patients have a final post operative visit at which a new eye glass prescription is issued. Those who elect to have their second eye treated within the month usually will wait until a month after their second eye is treated to receive an updated eyeglass prescription.
As compared to just about any other surgical procedure, cataract surgery is safe and well tolerated. Few medical treatments are as likely to improve quality of life and increase personal safety and sense of well being. Diminished vision is accepted by many older people as a consequence of aging, and treatment is not requested nor sought out. Poor vision is accompanied by added risks on the roadway and in walking about. Many falls and accidents occur because of poor vision. It is prudent to maintain the quality of your eyesight, just as it is to keep your motor vehicle in proper operating condition.
Advances In Lens Implant Technology
Recovery of clear vision has always been the goal of cataract surgery. Prior to the development of intraocular lens implants, cataract surgery patients needed to wear thick eyeglass lenses or contact lenses to see well. Implant lenses represent a tremendous leap forward in technology, and have served millions of patients well. Implant lenses last indefinitely and have an extremely low frequency of complication. Modern cataract surgery has become so refined as to now be thought of as a “refractive” surgical procedure. This means that specific visual goals can be met, such as relieving the need for eyeglass correction after surgery. For many people who have worn eyeglasses much of their lives, this is an enormous additional benefit to surgery.
All people over forty-five years of age become aware that different eyeglass lenses become necessary for correction of near and distance vision. This problem is referred to as presbyopia, and occurs because of stiffening of the aging human lens. Near focusing flexibility called accommodation progressively diminishes until it is no longer present at around sixty years of age. Many people feel that the development of presbyopia is the most aggravating visual change they experience in their adult life. For these people, the correction of presbyopia with the use of a multifocal or accommodating lens implant holds special attraction. These implants offer correction of distance, intermediate, and near vision allowing a much lessened reliance on eyeglasses after the cataract operation.
Several intraocular lenses are currently marketed in the United States offering correction for distance and near vision. These include the Alcon Restore lens and the Crystalens by Bausch and Lomb. The first is considered a multifocal lens and the latter is called an accommodating lens. The Restore lens offers excellent distance and near vision, and the Crystalens provides better focus for distance and intermediate vision (e.g. computer work).
Another vision problem addressed at the time of cataract surgery is astigmatism. Astigmatism exists when the surface of the cornea is shaped more like a football, with flatter and steeper curves, than like a basketball. Astigmatism creates blur, and can be neutralized with eyeglass lenses or contact lenses. Toric intraocular lens implants, correcting astigmatism are available for cataract surgery. Alternatively, astigmatism can be surgically corrected by making corneal incisions with a diamond blade knife or an Excimer laser. All of these methods result in clearer vision and lessen the need to use eyeglasses after cataract surgery.
Advances in Cataract Surgery Technique
Earlier it was mentioned that the cataract removal procedure performed most commonly today is the ultrasound technique, phacoemulsification, in which the cataract lens is broken up inside the eye and is removed with suction. This technique has the advantage of permitting a small incision that can be self-sealing and left without a suture closure. In 2013 an excimer laser instrument for the creation of cataract surgery incisions and for the partial disruption of the lens became available in the United States. This instrument ushers in the era of “laser cataract surgery” and offers the precision and safety of computer monitored laser surgery directed by a physician. This technique has several advantages as compared to traditional methods and is considered a significant advancement for patients electing to upgrade their implant lens to a presbyopia correcting lens or a toric lens. This laser also expands the availability of presbyopia correcting lenses to patients with moderate astigmatism.