Types of Cataracts
A 68-year-old patient presents with complaints of progressively worsening vision. They describe difficulty with night driving, increased glare around lights, and a noticeable yellowing of their vision. Upon examination, you find that the cataract appears to be primarily affecting the centre of the lens. What type of cataract is it?
- Cortical Cataract
- Posterior Subcapsular Cataract
- Nuclear Cataract
- Congenital Cataract
Nuclear Cataract - Results in gradual blurring, yellowing or browning of vision, and can sometimes temporarily improve near vision.
What are the modifiable risk factors associated with cataract development
UV exposure, smoking, sedentary lifestyle
What structure captures the light that enters the eyes and translates what you see
Retina
What is the most common type of cataract?
Nuclear cataracts develop slowly in the center (nucleus) of the lens, leading to a gradual loss of vision. They often cause a yellowing or browning of the lens, which can affect color perception and contrast sensitivity
Name 5 risk factors for cataracts
Aging >65 years, Diabetes, Family Hx, Sun exposure, smoking, obesity, hypertension, past eye injury/inflammation, previous eye surgery, steroid medication use
Describe two things that happen to your eye lens when you get older
- Lens in your eyes get less flexible, less clear and thicker
- Proteins in your eye lens starts to break down and clump together
These images show what a patient with Nuclear cataracts, cortical cataracts, posterior subcapsular cataracts?
Nuclear Cataracts: Generally cause gradual blurring, yellowing or browning of vision, and decreased contrast sensitivity, but not a black surrounding of vision.
Cortical Cataracts: Cause glare and difficulty with night vision, leading to visual disturbances such as halos, but not typically a black surrounding.
Posterior Subcapsular Cataracts: Affect near vision and cause glare but are less likely to result in a dark surrounding of vision.
Use of what types of medication has been associated with cataract development
Steroids
Name 3 signs of congenital cataracts in infants who cannot verbally explain their symptoms
- Leukocoria
- Nystagmus
- Lack of visual response
- Absent or abnormal red reflex
What are ways you can categorise different types of cataracts? Name two types
By cause or by location
Cataracts affecting the center of the lens, called nuclear cataracts. A nuclear cataract may at first cause objects far away to be blurry but objects up close to look clear, even improving your reading vision for a short time. But with time, the lens slowly turns more yellow or brown and makes your vision worse. It may become difficult to tell colors apart.
Cataracts that affect the edges of the lens, called cortical cataracts. A cortical cataract begins as white, wedge-shaped spots or streaks on the outer edge of the lens cortex. As the cataract slowly grows, the streaks spread to the center and affect light passing through the lens.
Cataracts that affect the back of the lens, called posterior subcapsular cataracts. A posterior subcapsular cataract starts as a small spot that usually forms near the back of the lens, right in the path of light. A posterior subcapsular cataract often affects your reading vision. It also may reduce your vision in bright light and cause glare or halos around lights at night. These types of cataracts tend to grow faster than others.
Cataracts you're born with, called congenital cataracts. Some people are born with cataracts or develop them during childhood. These cataracts may be passed down from parents. They also may be associated with an infection or trauma while in the womb.
Name a metabolic or hereditary condition that might predispose you to developing cataracts?
Wilson's disease, galactosaemia, myotonic dystrophy
List and explain 4 symptoms of cataracts in adults
Clouded, blurred or dim vision
Trouble seeing at night
Sensitivity to light and glare
Need for brighter light for reading and other activities.
Seeing "halos" around lights.
Frequent changes in eyeglass or contact lens prescription.
Fading or yellowing of colors.
Double vision in one eye
Red reflects
Leukocoria