Lens

Question 1

What does a spherical lens do?

Answer 1

Relaxes the zonules, and accommodates for closer distances

Question 2

Ovoid lens - how? why?

Answer 2

Tensed zonules - for distance

Question 3

Microphakia - what is it? how does it appear?

Answer 3

Lens is too small, may see the equator of the lens & the ciliary processes/bodies
Micro = small; phakic = lens (greek)

Question 4

Congenital issues with the lens

Answer 4

Microphakia
Lens coloboma (hole in the lens)
Cataract

Question 5

Lens coloboma

Answer 5

Hole in the lens: Not going to be a donut, more like a notch (piece that is missing off of the lens) but this is extremely rare.
Coloboma in greek = mutilated

Question 6

Cataract (what, type, prevalence)

Answer 6

Opaque lens: In the centre if congenital, in the nucleus. Most common congenital abnormality.

Question 7

How do we classify cataracts? (4)

Answer 7

Age of onset
Progression
Location
Causes

Question 8

Cataract - Stages of maturity (5)

Answer 8

– Incipient (growing/emerging)
– Immature or incomplete 
– Mature or complete
– Hyper-mature 
– Morgagnian (cortex has liquefied and the nucleus moves freely within the lens)

Question 9

Cataract - location (4)

Answer 9

– Capsular
– Cortical
– Nuclear
– Equatorial

Question 10

Cataract - Causes (6)

Answer 10

• Congenital
• Genetic
• Nutritional (lack of arginine)
• Diabetes mellitus (can happen quickly)
• Traumatic
• Uveitis (chronic)

Question 11

Can we medically treat cataracts?

Answer 11

Not successful, but keeps on marketing drops to cure cataracts.
If there is mild to moderate uveitis, you can use NSAIDs.
If there is severe uveitis, go with steroids.
(topical or systemic)

Question 12

What do you do prior to referring for cataract surgery? during surgery? post-surgery?

Answer 12

1. Make sure you have a stable patient (diabetes, ulcers, uveitis all controlled)
2. Do an ERG/Ocular ultrasound to make sure the retina is ok
3. Phacoemulsification, intra-ocular lens implant
4. Watch intra-ocular pressure, wean off/down medications.

Question 13

Nuclear sclerosis (what does it look like? effects? what still works? treatment?)

Answer 13

Lens gets compressed, looks pearly
Night vision can be affected
Still see tapetal reflex, can still do a fundic exam (retina, rental blood vessels, optic nerve)
Don’t treat surgically

Question 14

Causes of lens luxation
Primary - 1
Secondary - 3

Answer 14

1. Primary (congenital/genetic)

2. Secondary (uveitis, trauma, chronic glaucoma - eye becomes too big, zonules can pop)

Question 15

Lens luxation positions (3)

Answer 15

Subluxation
Posterior
Anterior

Question 16

Treatment for lens luxation

Answer 16

Treat the underlying cause
Surgically extract the lens right away
Or if you can’t enucleate/eviscerate (if you have a blind and painful eye)