How are cataracts diagnosed?

Last week, we spoke about cataracts and their formation. The next obvious question is:

How are cataracts diagnosed?

A cataract is not readily visible because it is inside the eye. This clouding of the lens inside the eye is mostly diagnosed during a comprehensive eye examination. Several specialized instruments are used to determine the type, location and size of the cataract.{{more}} Most of these instruments allow thorough inspection of the inside of the eye. The pupil is usually dilated for better visibility of the lens. The primary instruments used are a slit lamp and a direct or indirect ophthalmoscope.

Once the cataract is diagnosed, other tests such as glare testing, contrast sensitivity can be used to determine the degree of vision interference caused by the cataract. A test called potential acuity measurement (PAM) can be used to determine how much vision might be obtained after surgery.

An ultrasound test, called the A-scan, is used to determine the power of the lens implant and the length of the eye. Depending on individual circumstances, other tests such as an endothelial cell count may be performed to further determine if the visual outcome after surgery is performed would be good.

This brings us to the treatment of cataracts:

Cataracts cannot be removed by the use of certain medications, a change in diet or eye drops. The only way to restore one’s vision is to surgically remove, the cloudy cataract. Once the cloudy offending lens has been removed an artificial lens (IOL) is implanted into the eye. This lens provides clear vision for the patient.

Intraocular lens implant

So, when should cataract surgery be ideally performed?

Many years ago, doctors used to tell their patients to wait for the cataract to get “ripe” before surgery can be performed. This is no longer the case. The development of a cataract does not mean one has to have surgery immediately. When loss of vision starts to interfere with one’s daily activities, then is when a cataract should be removed.

97% of cataract surgeries are now performed as outpatient surgery. Before the procedure, the eye is numbed with an anesthetic. Some patients are given medication to help them relax and keep them comfortable during the procedure. Most patients can go home practically immediately after the procedure. Most are given pain medication, although it is not always necessary for some.

Next week, we’ll discuss the results that can be expected after cataract surgery. We’ll also discuss some advanced techniques.

Dr Kenneth Onu is a resident Consultant Ophthalmologist at the Beachmont Eye Institute/Eyes R Us Send questions to: Beachmont@gmail.com

Tel: 784 456-1210