Cortical Cataracts: Symptoms, Causes & Treatment

Cortical cataracts form outside the eye lens in the cortex portion of the eye. This type of cataract can extend from the outside to the inside of the lens, making vision blurry. 

They are common in people over 50 years old as well as individuals with diabetes. 

Cortical cataracts are considered very treatable via surgery. Most people recover vision quickly.

Symptoms of Cortical Cataracts

The symptoms of a cortical cataract may include the following:

• Vision becoming gradually blurry
• Objects appearing hazy or opaque, starting from the outside edges
• Opaqueness moving from the edges toward the center of vision
• Glares around lights at night 
• Walking and driving becoming uncomfortable
• The appearance of wedge-like or spoke-like white streaks
• Difficulty seeing in bright light

In addition, due to eye changes, you may notice that it is hard to tell similar colors apart from one another. It may be difficult to assess the distance of objects. You may also notice double vision in one eye, called monocular diplopia. 

It is possible to experience one, several, or all of the above symptoms. 

If you notice changes in your vision, it is important to take action quickly. There is no advantage to delaying, as waiting too long can create excess pressure in the eye known as lens-induced glaucoma. If left untreated, it can damage vision.

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Causes of Cortical Cataracts

The key causes of cortical cataracts are eye injury, aging, and a family history of cataracts.

Eye problems, such as previous eye injuries and inflammation, may cause cortical cataracts. Previous eye surgery is correlated with an increase in cortical cataracts.

Researchers are studying the biological mechanisms that cause cataracts to develop. One study at the University of Arizona is examining the role of protein ion channels in the development of cataracts. This study may lead the way to develop nonsurgical treatments for age-related eye diseases.

Risk Factors

Some of the risk factors for cortical cataracts include medical conditions that can be influenced by lifestyle choices, such as diabetes and hypertension. Autoimmune diseases, such as rheumatoid arthritis, may also be a risk factor.

Lifestyle risk factors for cortical cataracts include the following:

• Heavy and chronic smoking
• Excessive use of alcohol
• Obesity
• Excessive use of steroid drugs
• Excessive exposure to UV light

A family history of cataracts is a risk factor that you can’t control. Some studies estimate that genetics make up 37 to 48 percent of the likelihood of cortical cataract development.

Prevention of Cortical Cataracts

The risk of developing cortical cataracts can be reduced with lifestyle changes. Even if you have a family history of cataracts, you can still reduce other risk factors by making some changes.

• Stop smoking.
• Maintain a healthy diet, rich in antioxidants.
• Manage diabetes with proper diet, exercise, and care.
• Protect your eyes from exposure to UV rays.
• Get regular eye exams.

Stop Smoking

A basic preventative measure for cataracts is to stop smoking. If you are ready to stop smoking, you can get free support at 1-800-QUIT-Now (1-800-784-8669).

Eat a Healthy Diet

Studies show that a healthy diet is linked to a reduced risk of cataract development. In particular, nutrition plays a role in the formation of age-related cataracts.

Some research shows that a healthy diet, rich in antioxidants found in vegetables and fruits, can play a role in slowing the aging process and protecting against cataract formation.

In addition, nutrition guidelines suggest that a healthy diet rich in vitamins and minerals can potentially help postpone the development of cortical cataracts. Healthy choices include eating a lot of fruits and vegetables and focusing on dark leafy greens, such as collard greens, kale, and spinach.

According to the American Optometric Association, vitamins and nutrients play a role in reducing the risk of chronic eye diseases. Some of the top vitamins for eye health include lutein and zeaxanthin, vitamin C, vitamin E, essential fatty acids, and zinc.

Manage Diabetes

Talk with your doctor about how to manage your diabetes. Consider lifestyle modifications, like diet and exercise, that can support optimal blood sugar levels and overall eye health. 

Reduce Sun Exposure

Protect your eyes from UV light by wearing a hat and sunglasses regularly. According to the National Eye Institute, preventative measures to protect your eyes from the sun can reduce your risk of cataracts. 

Limit Steroid Use

Consider reducing steroid use, as continued use of steroids is considered to be a risk factor.

Get Regular Eye Exams

As we age, it is important to have regular eye exams to catch the early development of a cataract. 

The American Academy of Ophthalmology advises getting an eye exam at age 40 to create a baseline. If you have diabetes, high blood pressure, or a family history of eye disease, consider getting a baseline exam sooner.

Get a dilated eye exam at least once every two years if you are over 60 years old.

Treatment for Cortical Cataracts

Treatment can be managed progressively to match the rate of cataract growth. 

Corrective Lenses & Monitoring

For small or slow-growing cataracts, you may be able to manage by using prescription eyewear to see clearly. Simple lifestyle choices may include limiting driving at night and wearing anti-glare sunglasses.

Your eye doctor will monitor the growth of your cataract until they deem surgery is needed.

Cataract Surgery

As the condition progresses, surgery is typically recommended to replace the clouded lens. This is the only effective treatment for cataracts, as there is no cure. It must be removed.

The surgical procedure replaces the cloudy natural lens with a clear man-made lens to make vision clearer. This treatment is often done in an outpatient setting, and it is quite quick, often lasting only 20 minutes.

Two types of surgery can treat cortical cataracts:

• Phacoemulsification employs a hand-held tool that emits an ultrasonic pulse to break up the cataract. The pieces are gently suctioned out of the eye.
  
  After this procedure, your surgeon carefully replaces the lens with a new IOL, or intraocular lens. This clear, synthetic lens makes it possible to see clearly again.

• Femtosecond cataract surgery takes phacoemulsification to the next level. Using a laser, a tiny opening is made in the eye. The laser breaks up the cataract particles before they are removed, and an IOL is placed. Due to enhanced precision, this surgery offers safe and reliable outcomes.

Talk with your ophthalmologist to evaluate the best option for cataract surgery for your situation.

Cortical Cataracts FAQs

How common are cortical cataracts?

In one hospital-based study, cortical cataracts made up about 16 percent of cataract cases, with nuclear cataracts making up about 84 percent of cases.

According to the National Eye Institute, the number of people affected by cataracts is expected to double by 2050, from 24.4 million to approximately 50 million people. 

What is the difference between cortical cataracts and nuclear cataracts?

A cortical cataract forms in the cortex of the eye, outside of the lens. A nuclear cataract forms in the center of the lens called the nucleus. Cortical cataracts are often found in individuals with diabetes. 

How are cortical cataracts treated?

In their early stages, cortical cataracts are treated with corrective eyewear like glasses. In later stages, they are removed via cataract surgery. A synthetic lens is put in place of the natural lens that is removed, allowing clear vision to be restored. 

How quickly do cortical cataracts progress?

Cortical cataracts generally progress slowly; however, the timeline will vary from person to person. See an ophthalmologist regularly so they can monitor the progression of your cortical cataract. 

References

1. Cataracts. University of Irvine (UCI).

2. Approach to Diplopia. American Optometric Association (AOA).

3. Maintaining Transparency: Study to Focus on Causes of Cataracts. (February 2022). National Eye Institute (NEI).

4. The Genetics of Cataract. (July 2001). Investigative Ophthalmology & Visual Science.

5. Causes of Cataract. (May 2019). National Eye Institute.

6. How to Help Prevent Cataract. (November 2010). Review of Optometry.

7. Cataract Data and Statistics. (July 2019). National Eye Institute.

8. Healthy Diets and the Subsequent Prevalence of Nuclear Cataract in Women. (June 2010). JAMA Ophthalmology. 

9. Nutrition Guide for Clinicians: Cataract. Physicians Committee for Responsible Medicine.

10. Cataracts and Their Treatment in People With Diabetes Prevention and Management of Diabetes-Related Eye Disease. (May 2019). American Diabetes Association.

11. New Research Sheds Light on How UV Rays May Contribute to Cataract. (June 2014). National Eye Institute.

12. Diet and Nutrition. American Optometric Association.

13. Get an Eye Disease Screening at 40. American Academy of Ophthalmology.

14. Systemic and Inhaled Corticosteroids and the Long-Term Incidence of Age-Related Cataract. (May 2008). Investigative Ophthalmology & Visual Science.