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Taking A Closer Look At Cataracts

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Today, over 24.4 million Americans over the age of 40 suffer from cataracts. By the age of 75, it's projected that an estimated 50% of Americans will have cataracts. If left untreated, the condition can result in continual vision loss — ultimately leading to blindness. While the term "blindness" is often thought as an irreversible loss of vision, blindness caused by cataracts can actually be restored with surgery and implantation of an intraocular lens (IOL). 

Nonetheless, the condition doesn't have to advance to this point. Cataracts are easily diagnosable during a dilated eye exam. Therefore, it is extremely important that you emphasize the importance of regular eye exams to all of your patients! Let's put cataracts under the microscope to learn more about the condition. 

What Are Cataracts?

Cataracts are a condition in which the naturally clear, crystalline lens inside the eye becomes cloudy over time. Patients who have cataracts often explain the experience as if they are looking through a fogged-up or frosty window. The opaque vision caused by cataracts can cause difficulty reading, driving a car (particularly at night), and seeing facial expressions.  

Cataracts tend to develop relatively slowly and may not cause a visual disturbance in the beginning. However, over time, cataracts can cause serious complications with your patient’s ability to see. 

If the impaired vision from cataracts hinders your patient’s daily activities, they may elect to have cataract surgery. And today's cataract surgery is typically a very effective and safe procedure. 

How Do Cataracts Develop?

Cataracts form in the lens of the eye, which is situated behind the iris. The lens focuses light that passes through the eye to produce clear images on the retina. The retina is the light-sensitive membrane in the back of the eye that acts similar to a camera's image sensor. 

As an individual naturally ages, the lens in the eye becomes thicker, less transparent, and less flexible. Medical conditions and age cause tissues inside of the lens to clump together and deteriorate, which creates small, cloudy areas. 

Over time, the cataract will continue to develop while gaining density and taking up more space inside of the lens. In turn, this blocks and scatters light as it passes through the lens which prevents clear, sharply defined images from reaching the retina.  

Cataracts typically develop in both of an individual's eyes, but not always  at the same rate. For instance, the cataract in the left eye could be much more advanced than the cataract in the right eye, which causes a variance in vision between the eyes. 

What Causes Cataracts?

The most common cause of cataracts is aging. Around the age of 40, the eye's normal proteins begin to break down, which can cause the lens to get cloudy. On the other hand, cataracts can also form as a result of an injury, causing the tissue that makes up the eye's lens to change. Other causes of cataracts include:

  • Having certain medical conditions, like diabetes
  • Spending significant time in the sun without protective eyewear
  • Having immediate family members who have had cataracts
  • Eye surgery, eye injury, or treatments of radiation to the upper body
  • Certain medicines like corticosteroids have been linked to the early onset of cataracts.

The majority of age-related cataracts will develop progressively over a period of time. Other cataracts can quickly develop, like in a younger individual who may have diabetes. 

Different Types of Cataracts

There are three different types of age-related cataracts: nuclear sclerotic, cortical cataracts, and posterior subcapsular cataracts. In addition to age-related cataracts, congenital cataracts also exist. 

  1. Nuclear cataracts impact the center of the lens and tend to result in more nearsightedness. They can even cause a temporary improvement in your patient’s reading vision. However, over time, the cataract will further cloud your patient’s vision and will turn densely yellow. It also may eventually turn brown. 
  2. Cortical cataracts occur around the inside edges of the lens. This type of cataract starts out whitish with streaks or wedge-shaped opacities on the edge of the lens cortex. When it progresses, the streaks tend to stretch to the center and hinder light from passing through the center of the lens. 
  3. Posterior subcapsular cataracts affect the back of the lens. These cataracts tend to begin smaller and are closer to the back of the lens, which is directly in the light path. Posterior subcapsular cataracts usually cause halos or glare around lights at night, limit vision in bright light, and interfere with reading. Posterior subcapsular cataracts often progress significantly faster than other cataracts do. 
  4. Congenital cataracts are formed at birth and can be caused by an inherited genetic trait or with more extensive syndromes or diseases. 

Although these are the most common causes of cataracts, some may result from undetermined causes. These cataracts cover a broad spectrum of severity. Some lens opacities never fully develop or cause problems while others can produce full visual impairment.

Questions? Contact Keeler today!

We have been manufacturing diagnostic ophthalmic equipment for eye care professionals for over 100 years in our vision to contribute to a world without vision loss. We have a large inventory of ultrasonic and diagnostic equipment as well as a pharmaceutical and PPE line. If you have any questions or would like more information, please call our toll free number at 1-800-523-5620 or email us at [email protected].

About the Author Eugene VanArsdale

Eugene is the Director of Marketing Communications at Keeler Instruments. He has been with Keeler since 1982 and is co-holder of two patents for the company. Eugene has a true passion for the eye care industry and has dedicated himself to understanding the ins and outs of the optometric and ophthalmic equipment market.