Causes and Risk Factors for the Development of a Cataract

Cataracts progress at different rates in different individuals. This is due to the fact that lifestyle, disease processes, and inheritance patterns all play a major role in cataract progression. There are lifestyle factors that can either accelerate or retard the progression of cataracts, which means there are certain types of behavior modification we can make that may help to slow the rate of cataract progression. In other words, cataracts are similar to other disease processes in that behavior modification may mitigate or prevent the progression of the disease.

The following list includes the most common causes of cataracts and the major risk factors associated with them. There are other less common factors that relate to specific disease conditions, or that lead to types of cataracts that tend not to cause decreased vision. This list is designed to give you a basic understanding of the disease processes and risk factors that commonly lead to cataracts.

Age

Age is a clear risk factor for cataract development. But,if you live a healthy lifestyle, age becomes a less important factor in cataract progression.

Family History

Like many other diseases, cataracts do run in families. If you have family members who have had significant cataracts at a young age, you may also be at risk.

Diabetes Mellitus

All patients with diabetes mellitus are at risk of early formation of nuclear, cortical and posterior subcapsular cataracts. The better your diabetes is controlled, the lower your risk of cataract progression. In other words, strict glucose control yields a lower risk of progression, as is true with many other complications of diabetes.

Obesity

This is a clear risk factor associated with cataract progression, and is independent of diabetes mellitus. In addition, it puts you at risk of developing a myriad of other medical problems and is best avoided for long-term good health.

High Blood Pressure (Hypertension)

Studies have shown mixed results regarding the effect of hypertension on the formation of cataracts; some have shown a definite risk, while others have not. However, as with obesity and diabetes, there are many other health problems that can arise from this condition. Therefore, it is best controlled.

Corticosteroid Use

There are several methods of steroid delivery commonly in use today. These include:

intravenous and intramuscular (injections)

oral (by mouth)

inhaled (through the mouth or nose)

topically through skin creams, gels and ointments; and

in the eye with drops, ointments, injections or implants

Any of these steroids can lead to cataract formation. Cataract risk from steroids is typically dose- and duration-dependent. Low doses of short duration carry little risk, whereas chronic diseases that require long-term steroid treatment carry a much greater risk. Steroid use is also a risk factor for glaucoma; so, if you have a disease that requires frequent use of steroids, you should have a regular eye examination. In addition, you should contact your eye doctor if you notice any change in your vision.

Hormone Replacement Therapy in Women

A recent ophthalmological study, published in 2010 by Lindblad et al., showed that women who received hormone replacement therapy (HRT) for extended time periods showed a 14 percent increase in the risk of needing cataract surgery compared to women who had never received HRT. In addition, this study found that increased duration of treatment was associated with an increased risk of the need for cataract surgery. This effect was also increased when associated with alcohol intake greater than one drink per day.

If you are concerned about either steroid use or HRT, you should discuss this with the physician who prescribes these medicines for you. Do not stop your medicines without first consulting your prescribing physician. Rest assured that cataracts are successfully treated in most cases; so, if you need these medicines, cataract formation is an acceptable side effect for most people.

Smoking

Smoking is clearly associated with cataract formation and progression. People who smoke are at increased risk of requiring cataract surgery at younger ages than non-smokers. In addition, smoking leads to many other health problems, including heart disease and cancer.

Excessive Alcohol Intake

Studies show conflicting results regarding the effect of alcohol on cataract formation. Excessive alcohol intake may be associated with an increased risk of cataracts. As with high blood pressure, obesity and smoking, excessive alcohol intake is associated with other medical problems and is best avoided.

Trauma

There are four types of eye trauma that can lead to cataracts. These are blunt trauma, penetrating trauma, chemical injuries and electrical injuries.

Blunt trauma occurs when the eye is hit with a blunt object, such as an airbag or a ball. Penetrating trauma refers to injuries where the eye wall is ruptured or punctured. This usually results from sharp objects, such as knives, scissors or glass. Chemical injuries can result from a variety of different chemicals if the noxious substance is splashed in the eye. Electrical injuries result from electrical shock.

Intraocular Inflammation

This is called iritis or uveitis and refers to inflammation that occurs inside the eye itself. A single episode of iritis is typically not a problem, but chronicity of the disease leads to an increased risk of cataract formation and progression.

Radiation Exposure

This includes both ionizing radiation (radiation used in x-rays, CT scans and for cancer treatment where the eye is exposed) and ultraviolet radiation (sun and/or tanning bed exposure).

Previous Eye Surgery

Any type of surgery inside the eye can lead to a cataract. This does not include surgery performed completely outside or around the eye, such as removal of excess skin in the eyelid, or repair of a droopy eyelid.