Everyone will need cataract surgery. Just like grey hair, everyone gets cataracts; some early in life and some later in life. Patients with diabetes tend to get cataracts at an earlier age, too.
The best time for a patient with diabetes to consider cataract surgery is when your diabetic retinopathy, if present, is stable. More specifically, any diabetic macular edema should be controlled before considering cataract surgery.
Diabetic macular edema, or CSME (clinically significant macular edema) is the most common side effect of diabetic retinopathy. It occurs in almost all patients with diabetic retinopathy (and this occurs in almost every patient).
Cataract surgery is known to worsen pre-existing macular edema. The worse the edema, the worse your vision.
All too often, I see patients who have had perfect cataract surgery only to have the vision get blurrier over the following weeks and months.
In most cases, vision will improve after cataract surgery. The resultant vision, however, will be dependent upon the relative health of your macula.
Remember, diabetic retinopathy can cause vision loss in two ways: macular edema and/or so-called macular non-perfusion.
Non-perfusion is a complication of diabetic retinopathy where the fine net work of blood vessels which nourish the macula, simply occlude or shut off. Vision is severely affected. Fortunately, this does not happen too often.
Most vision loss in diabetic patients occurs with diabetic macular edema. This swelling of the macula (the central part of the retina) is directly proportional to vision loss. The more the edema, the worse the vision.
My goal as your retina specialist is to limit macular edema as much as possible.
The most common way to treat CSME/diabetic macular edema is with laser treatment. Laser photocoagulation is still the gold standard in treating DME.
Lucentis, Avastin or other anti-VEGF medications can also be used to treat macular edema not responsive to laser. Laser does not work well in every patient and not every patient can be lasered (for example, if the microaneurysms are too close to the center of the macula).
Intraocular steroids (Triamcinalone/Kenalog, Ozurdex) may also be used on stubborn cases, too.
Ask your retina specialist specifically about your suitability for cataract surgery.
Almost everyone needs an intraocular lens (IOL) to replace the cataract. There are several types of IOLs from which to choose; standard monofocal or the new multi-focal lenses (e.g. ReSTOR, Crystalens).
The standard monofocal lens is used to maximize your distance vision and you’ll need reading glasses for up close tasks. The multi-focal lenses may also give you the ability to read without glasses. Ask your eye doctor about the differences between them.
Regardless of the type of lens, however, your resultant vision will be the same. In patients with diabetic retinopathy, the health of the macula will determine your best vision after cataract surgery.
What Does This Mean?
Everyone, including patients with diabetes, will get cataracts. In everyone, the visual results are dependent upon the relative health of the retina, more specifically the macula.
Patients with macular degeneration and diabetes (two diseases which principally affect the macula) must be aware of their macular health in addition to the cataracts.
Regardless of the type of glasses, contacts or intraocular implants, the vision can improve only as much as the health of the macula.