Cataract

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  • Created by: z
  • Created on: 13-03-16 17:05

Cataract

  • "opacification of the naturally crystalline lens"
  • 3 types
    • nuclear sclerosis- lens becomes yellow/brown
    • cortical
    • posterior subcapsular
  • assoc w/ gradula deterioration of vision
  • commonest cause of blindness worldwide
  • 30% have other eye problems
    • 11% glaucoma
    • 17% ARMD
    • 3% diabetic retinopathy
  • incr incidence w/ ageing pop
  • 57% who have ctaract surgery have another condition
    • 30% HTN
    • 18% arthritis
    • 11% diabetes
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Causes of cataracts

  • age related (commonest)
  • secondary to ocualr disese
    • e.g. post inflammatory, uveitis > post subcaps cataract
  • secondary to systemic disease 
    • e.g. DM
  • traumatic - lens capsule disruption
  • drug induced 
    • systemic corticosteroids > post subcaps c
  • congenital
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Cataract: symptoms and examination

  • symptoms
    • gradual blurred, misty vision
    • glare
  • examination
    • pupils appear grey/white with pen torch
    • nuclear sclerotic c may appear yellow/brown
    • reduced red reflex usng a direct ophthalmoscope (NB indirect ophthalmoscope= appears upside down)
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Types of cataract

  • D- nuclear sclerosis (most common)
  • A, B, C- cortical
  • E -posterior subcapsular (caused by corticosterois, uveitis)
  • F-hypermature: lens proteins completely opaque and liquified (mature=completely opaque)
  • (http://www.oculist.net/others/ebook/generalophthal/vaughan/public/co_figures/ch008/ch8fg1.jpg)
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Cataract treatment

  • indications for treatment 
    • level vision resricts normal activity
    • pt factors e.g. if young may need to drive
    • ocular factors- some types of cataracts can induce glaucoma or uveitis so must remove
  • refraction - myopic spectacles 
  • surgery (most common operation under NHS)
    • removal by phakoemulsification and implantation of artificial intraocular lens
    • remove whole lens except for posterior capsule
    • once removed the eye is highly hypermetropic so insert artificial intraocular lens (IOL)
    • under LA - day case
    • 4mm incision, remove anterior lens capsule, high speend ultrasonic tip cuts nucleus into tiny bits and aspirates them, irrigation and aspiration of remaining cortex, insert foldable IOL
    • no sutures
    • complications: peri-op - rupture of posterior capsule (3%)
      • post-op - endophthalmitis (0.1%), haemorrhage, uveitis, glaucoma, macular oedema, retinal detachement, opacification of posterior lens capsule (late)
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