6.1.6 Cataract

Question 1

what is a nuclear cataract

Answer 1

• yellowing and hardening of the central portion of the crystalline lens and it occurs slowly over years
  
  • General haziness of distance & near
  • Increased myopia
  • Lowered ability to discern colour - reduced CS
  • Glare & difficulty night driving
  • Monocular diplopia

Question 2

what is a cortical cataract

Answer 2

• when the portion of lens fibers surrounding the nucleus become opacified. The impact on vision is related to how close the opacities are to the center of the visual axis
  
  • Glare!!
  • Decreased vision & CS - relates to how close it is to the central axis

Question 3

what is a PSC

Answer 3

• opacities located in the most posterior cortical layer, directly under the lens capsule.
  
  • Very close to central axis so great impact on vision
  • Glare

Question 4

referral criteria

Answer 4

• px wants to proceed with surgery
• vision is less than 6/12, or better than 6/12 and having significant cataract related visual problems
• reasons should apply at the time of referral, note this on the record and that it is likely to get worse

Question 5

exclusion criteria for cataract surgery

Answer 5

• under 18
• weigh 250kg or more
• unable to lie flat for 30 mins
• uncontrolled airways

Question 6

risks of cataract surgery

Answer 6

• 4% chance of any complication
• 1% chance of reduced vision
• 0.1% chance of total loss of vision
• Posterior capsular opacification (PCO) - can happen anytime after surgery; clouding effect; treated with YAG laser capsulotomy with immediate visual improvement
• Posterior capsule rupture/Vitreous loss - can happen during surgery
• Cystoid macula oedema (CMO) - peak incidence is about 6 to 8 weeks post-operatively
• Endophthalmitis - microorganisms that gain entry into the eye, infecting tissue & fluids within eyeball; treated with intravenous antibiotics
• Vitreous/Suprachoroidal Haemorrhage
• Retinal detachment; risk is increased in patients who have received YAG laser capsulotomy following surgery
• Lens Dislocation - rare