systemic disease, toxic and traumatic cataracts

By what mechanism does diabetes mellitus affect the lens?

increased glucose in AH enters lens, causing over hydration of the lens

What are the risk factors for diabetes mellitus affecting the lens?

1. duration of diabetes

2. control of blood sugar levels

How does diabetes mellitus affect the lens (what changes occur)?

1. RE changes

2. cortical vacuoles (imaged) - develop into opacities

3. cataracts (age-related, snowflake)

What cataract is associated with type 1 diabetes?

snowflake cataract

Who gets a snowflake cataract?

type 1 diabetics - 1-16% of T1DM

When do patients develop a snowflake cataract?

5 years after DM diagnosis

What is the presentation of a snowflake cataract?

1. grey-white branching opacities in snowflake appearance

2. eventually entire lens will turn white

What layer of the lens do snowflake cataracts start to develop in?

subcapsular (posterior subcapsular)

What is the age of onset for myotonic dystrophy?

20-30s

What are the ocular complications associated with myotonic dystrophy (what type of cataract)?

1. ptosis

2. EOM restriction

3. christmas tree cataract (imaged)

4. hypotony

Who gets Christmas tree cataracts?

myotonic dystrophy

What is the age of onset of a christmas tree cataract?

starts in 30s, starts affecting vision in 50s

What is the presentation of a christmas tree cataract?

polychromic (many colors) crystals in cortex - crystals will morph into stellate cataract

What are the polychromic crystals of christmas tree cataracts composed of?

1. cholesterol

2. lipids

3. calcium

What is atopic dermatitis associated with?

1. asthma

2. rhinitis

What increases the risk of developing a cataract in an atopic dermatitis patient?

1. FHx of eczema

2. asthma

3. hay fever

What is the onset of atopic dermatitis?

infantile onset

What two cataracts are seen in people with atopic dermatitis?

1. anterior subcapsular

2. posterior subcapsular

Who gets an anterior subcapsular cataract?

patients with atopic dermatitis

When do patients develop an anterior subcapsular cataract?

20s-40s

What is the presentation of an anterior subcapsular cataract?

1. shield-like plaque on anterior capsule

2. wrinkled anterior capsule

What systemically happens to patients with neurofibromatosis?

noncancerous tumors to form on the brain, spinal cord, and nerves

When does type 1 neurofibromatosis develop?

in childhood

What does type 1 neurofibromatosis cause?

1. bone deformities

2. learning disabilities

3. increase BP

When does type 2 neurofibromatosis develop?

in adulthood

What does type 2 neurofibromatosis cause?

1. hearing and vision loss

2. difficulty with balance

What types of cataracts are associated with neurofibromatosis?

1. posterior subcapsular

2. cortical

Are the cataracts with neurofibromatosis unilateral or bilateral?

bilateral

What is a toxic cataract?

medication induced cataract

What causes toxic cataracts?

1. oral and topical corticosteroids

2. chlorpromazine (antipsychotic) - significant amount of medication (1000 mg)

What is the presentation of a toxic cataract?

1. anterior star-shaped opacity

2. will not go away after discontinuing meds

What is a secondary cataract?

cataract that develops due to other ocular disease

What causes secondary cataracts?

1. chronic anterior uveitis

2. acute angle closure glaucoma

3. high myopia (>5D)

What type of cataract does chronic anterior uveitis cause?

PSC (posterior subcapsular cataract)

What is unique about a chronic anterior uveitis induced cataract?

rapid progression if posterior synechiae present

What does a glaukomflecken cataract look like?

1. grey-white subcapsular/capsular opacities within pupil area

2. may have pigment on lens as well

What kind of cataract does high myopia cause?

early onset of

1. PSC (posterior capsular cataract)

2. nuclear sclerotic

What is the most common cause of unilateral cataracts?

trauma

What type of cataract is associated with blunt trauma?

sunflower cataract

rupture of lens capsule which results in an influx of aqueous into the lens

What type of lens damage is associated with electric shock?

diffuse milky white opacification with snowflake-like opacities - subcapsular!

What type of lens damage is associated with infrared radiation?

exfoliation of the anterior capsule