A cataract is a clouding of the eye’s lens. The vast majority of cataracts are related to age although some children are born with them. Most people do not even realize they have a cataract, as cataracts grow very slowly and may not impede vision early on. After a number of years vision will likely be affected. When the cataract has become so dense that it compromises the patient’s quality of life, the patient and ophthalmologist will discuss the appropriate time to remove it. Surgery is the only treatment.
What Causes a Cataract?
The human lens is transparent so that light can travel through it easily. Although new cells are being made for the lens continuously throughout our lifetime, many factors combine as we age to cause areas in the lens to become cloudy, hard, and dense. The lens can then no longer transmit a clear picture to the retina where it can be processed and sent through the optic nerve to the brain. Some conditions may cause cataracts to form more quickly: ocular injury, other eye surgeries such as retinal surgery, diabetes, systemic inflammatory conditions, and some systemic medications such as steroids.
Typically patients will experience blurry vision, double vision, sensitivity to light, glare & haloes, difficulty with night driving, colors that appear washed out, and/or frequent changes to eyeglass prescriptions. An ophthalmologist or optometrist will be able to diagnose a cataract by looking through a slit-lamp during a dilated eye examination or by looking through an ophthalmoscope.
The only treatment for a visually significant cataract is surgery. During cataract surgery, the cloudy natural lens is removed through a tiny self-sealing incision and replaced with an artificial intraocular lens implant (IOL), thus restoring good visual function. Cataract surgery is one of the most common and successful surgical procedures performed in the US each year. Cataract surgery is performed on an outpatient basis and most commonly under topical anesthesia, which means there are no needles or injections around the eye and no need to wear a patch over the eye post-operatively.
The replacement IOL is chosen to fit your individual eye size and shape based on measurements taken before surgery. The type and power of the IOL will determine your need for glasses after surgery. In most cases, patients will experience both improved best possible vision as well as less dependence on glasses than before the procedure. There are many types of IOLs now available- some designed to treat specific additional conditions like astigmatism and presbyopia- and each has its own pros and cons. Your surgeon will discuss which IOL(s) may be best for you at your pre-op evaluation.
Posterior Capsule Opacity or PCO (sometimes called a Secondary Cataract)
Often at some point after cataract surgery (usually months to years later), scar tissue or haze can form on the sac that holds the IOL in place. If the sac clouds enough, your vision can be impaired- much like it was when the original cataract formed. If this becomes visually significant, it is best treated with an outpatient laser procedure called a YAG Laser Capsulotomy. YAG Capsulotomy uses laser light energy to open a central hole or window in the cloudy sac which allows light to pass through clearly and come to a sharp focus on the retina, thereby restoring your good quality vision. This procedure is NOT performed in an operating room, but rather at a machine very similar to the slit lamp your optometrist or ophthalmologist used to examine your eyes in the office.