CATARACT Flashcards
What is a cataract?
An opacity of the crystalline lens in the eye.
What are the most common types of cataracts?
Nuclear sclerosis - most common. Clouding of the central lens and myopic shift
Posterior subcapsular - more focal opacity of the posterior lens
Polar - localized, commonly inherited, lie in the visual axis
Dot opacities: common in normal lenses, also seen in diabetes and myotonic dystrophy
What is the most common cause of cataracts?
Age - UV light exposure
What are the systemic diseases associated with cataracts?
Diabetes Hypocalcaemia Galactosaemia Wilson's disease Myotonic dystrophy
What are the ocular pathologies associated with cataracts?
Trauma/postoperative
Uveitis
High myopia
Topical steroids
What are the medications associated with development of cataracts?
Systemic steroids - classically associated with posterior subscapular cataract
Anticholinesterase
Antipsychotics
Amiodarone
What are the symptoms associated with cataracts?
Loss of vision - gradual over 6-12 months
Glare - poor vision in bright light
Monocular diplopia (double vision in one eye) - rare
What are the signs associated with cataracts?
Lens opacity
Inflammation
Pseudo-exfoliation syndrome - build up of proteins that can block the trabecular meshwork
Anterior segment dysgenesis
How is cataract treated?
Surgical removal
What happens in cataract removal surgery?
The lens is accessed via the cornea and then the capsule that it sits in. It is then broken up using hydrodissection and high frequency ultrasound (phacoemulsification). The lens material is aspirated and replaced with an artificial acrylic intraocular lens.
Post a cataract removal operation, what medications will patients need to take?
Anti-inflammatory (steroids)
Antibiotic drops
What are the complications associated with cataracts surgery?
Endophthalmitis - affects about 0.1% of intraocular surgeries
Raised IOP
Inflammation
Retinal detachment
Cystoid macular oedema
Posterior capsule opacification
What are the symptoms of endophthalmitis?
Early - very painful red eye with a hypopyon (pus in the anterior chamber)
Late - chronic inflammation with or without hypopyon
Each one of the following predisposes to cataract formation, except:
Down’s syndrome
Hypercalcaemia
Diabetes mellitus
Long-term steroid use
Congenital rubella infection
Hypercalcaemia
Hypocalcaemia, rather than hypercalcaemia, predisposes to cataract formation