Cataract - Optometric management, and surgical management + complications Flashcards
What is the most common cataract ?
Nuclear sclerotic cataract
What rx shift would someone with a NS cataract have?
More myopic
What were the number of cataract cases world wide by 2020?
30 mil
What percentage of the population over 65 have cataract ?
30%
What are 7 traumatic causes of cataract apart from age?
- Blunt trauma
- Penetrating injuries
- Concussion
- Infrared radiation
- Electric shock
- Ionizing radiation
- Post surgery
What type of cataract is this?
Traumatic cataract
What are some metabolic causes of cataract ?
- DM
- Hypoglycaemia
- Galactokinase deficiency
What are some other causes of cataract?
- Corticosteroids
- Secondary from anterior uveitis
- High myopia
- Rubella
- Down’s syndrome
- Myotonic dystrophy
What cataract is this ?
Polychromatic “Christmas tree’” cataract
Will a Christmas tree cataract always affect VAs?
No but may cause glare
What happens if you do not treat cataract ?
Nucleus becomes dark and cortex becomes soft
How would you examine the retina with a cataract that has got to this extent ?
Ultrasound
What cataract is this ?
End-stage cataract
What is Phacolytic glaucoma ?
End-stage Cataract Begins to breakdown inside the eye, then erodes, pressure goes up
What system is used to grade cataract ?
LOCS grading
What does the scale go up to for LOCS?
0.1-5.9, in practice we normally can just grade it medium, mild, marked ect
What will px with PSC complain of?
Glare when driving at night
How did WHO simplify the grading system?
Split it into 3 grade system
What is the Oculus Pentacam scanner ?
Scans the anterior pole using densitometry trace
What are some sx a px may complain of ?
- Light scatter
- glare
- Struggle driving at night
What is back scatter ?
Net curtain effect
(idk how to type it btu ask anisha to explain it because it is interesting)
Is there a 6/12 cut off for px to be referred with cataract ?
No- not anymore
What is couching?
An older technique involving a long sharp needle through the limbus and the opaque lens is the pushed through into the vitreous cavity
What is intra-capsular cryo-extraction?
What was done before Phacoemulsification, pulling out the whole lens using a big incision including the capsule
What is extra-capsular lens expression?
Making a gap or hole in the capsule and squeezing the nucleus out
What surgery is done now to remove a cataract ?
Phacoemulsification Surgery
What size incisions are used in Phacoemulsification Surgery ?
2mm
Do you need stitches in Phacoemulsification Surgery ?
No
What are five advantages of Phacoemulsification ?
- Minimally invasive
- Rapid visual rehabilitation
- Single post-op out px visit
- No stitches
- You can prescribe reading specs are 1month post op
How does a Phacoemulsification probe work ?
Uses high frequency oscillations to emulsify particles and sucks it all up
What does capsulorphexis mean?
Tearing the capsule, you create a circular gap in anterior capsule
Do you know the Phacoemulsification process?
What is the main Phacoemulsification Complications during surgery?
Posterior capsular Rupture where they have managed to go through posterior capsule and the vitreous comes forward
What is a very common post Phacoemulsification sugary complication ?
Posterior capsular opacification (PCO)
How can can posterior capsular opacification be treated?
YAG laser posterior capsulotomy
What % of children who have had cataract surgery will get PCO?
100%
What is a complication post-cataract surgery regarding the retina ?
Cystic macula oedema, also known as Irvine-Gas syndrome
What sx would a px with Irvine-Gass syndrome have?
Reduce VAs
How is macula oedema post cataract surgery resolved?
Spontaneously self limiting but can be healed quicker by using steroids
What is the name of the infection you can get post cataract surgery?
Endophthalmitis - VERY SERIOUS
What is the most common organism that causes endophthalmitis ?
Staphylococcus
What is the prevalence of RD post cataract ?
1/300
If you cannot see the capsule because the cataract is that bad, what do you stain it with?
Trypan blue
Is Phacoemulsification done under general or local anaesthetic?
Local
What does phakodonesis mean?
Mobile lens, moves about a lot so cannot do Phacoemulsification
As we cannot do Phacoemulsification On a phakodonesis lens, what do we do?
Remove the whole lens
What is aniridia ?
Iris damage
What are some things they can do to correct astigmatism during Phacoemulsification Surgery?
- Limbal relaxing incisions
- lasek or lasik
- Astigmatic IOLs
- Astigmatic keratotomy
What is astigmatic keratotomy ?
Incisions are put in the cornea to try and change to shape of the cornea
Which px have a greater chance of getting RD post cataract surgery ? And why?
High myopes because deeper AC, weaker zonules
Why are high hypermetropia px difficult to perform Phacoemulsification On?
Smaller eye, shallow AC, bulging eyes
Why would a multiple lens implant (piggy back lens) be used?
Increase refractive power of the lens if they require this correction
What is photodisruption ?
Modern approach to cataract surgery - uses a laser to cut up tissues & used to for capsulotomy (making an incision in the capsule)
What is an advantage of photo disruption?
Very accurate incisions made, time effective, you are left with a perfectly round capsulotomy
What laser is used to soften a cataract ?
Femto-laser, will be easier to remove cataract with Phacoemulsification
