Cataracts and visual loss: a common problem. (Advertising Supplement).

A cataract is a cloudiness or opacification of the natural lens of the eye, which is located behind the pupil and iris. Any disturbance in the clarity of the lens may interfere with vision, resulting in generalized blurriness, increased glare, decreased night vision, impaired depth perception, and color distortion.

Cataract formation may occur in utero, resulting in a congenital cataract. However, most occur as an aging change.

The lens of the eye is made up of an outer capsule that has tiny fibers, or zonules, which connect the lens to the ciliary body muscle, enabling the lens to change its shape and focus. This process of accommodation is what most people begin to lose after age 40, requiring reading glasses or bifocals. Inside the capsule is the cortex, and inside that is the center of the lens, or nucleus, which tends to harden and opacify with time.

Most cataract patients are over age 60. However, it is not uncommon for a certain percentage to develop visually significant cataracts in their 40s and 50s. In addition to aging, trauma, diabetes, poor nutrition, exposure to high levels of UV radiation, heredity, and some medications (particularly steroids) make cataract formation more likely at an earlier age.

Cataract formation in older patients tends to be a gradual process that may be very subtle or show no symptoms. In younger patients symptoms such as increased glare may present over a period of just a few months and ultimately reduce the acuity to a degree requiring surgery within six months. Initially the visual symptoms may be treated with a change in glasses or contact lenses, though surgery may be required if the needs of the patient cannot be met. The mere presence of a cataract does not (except in very rare circumstances) threaten the health of an eye. The indication for cataract surgery is therefore made based on the visual needs of the patient.

It used to be said that a cataract needed to be ripe (for the picking) to undergo surgery. This was true in years past due to the technique of cataract extraction that required the removal of the lens as a whole through a large incision. With current techniques the center of the lens is removed by breaking it into small pieces and aspirating it through a small incision. This process of "phacoemulsification" can be performed on very soft, or "unripe," lenses if the visual needs of the patient are compromised by a cloudiness of the lens.

The natural lens of the eye has a significant power that needs to be replaced either during or after cataract surgery. Current techniques enable the surgeon to place a foldable implant lens into the capsular bag, preventing the need for contact lenses or thick glasses. This procedure is performed under local anesthesia as an outpatient. The incision is so small that it is most often self-sealing without a stitch, taking less than 30 minutes to perform.

The patient is seen the following day, at which time antibiotic and anti-inflammatory drops are started. Glasses or standard contact lenses may be required to achieve the best possible vision four to six weeks later. Cataracts usually come in pairs, and the second eye can be operated on within four weeks if needed.

Occasionally a clouding of the capsule supporting the implant lens may occur within months or even years after surgery, again reducing vision. This is very easily treated with a YAG (ytretium, argon, gadalinium) laser by opening a hole in the supporting capsule without disturbing the position of the implant lens.

Cataract surgery is not without its risks, but with a skilled surgeon in a state-of-the-art facility, it is an excellent treatment for an otherwise debilitating problem.

Robert Fein field, M.D., is an Ophthalmologist on Staff at Providence Saint Joseph Medical Center and a former Chairman of the Medical Center's Ophthalmology Section