cataract Flashcards
definition
opacification of our native crystalline lens
most common cause of chronic visual loss in elderly
congenital causes
- a/w asthma
- developmental defect of lens
acquired causes
- old age (senile cataracts)
- metabolic (DM)
- eye trauma
- LT UV exposure
- radiation related
- drug usage - corticosteroids
presentation
- gradual onset, progressive (chronic visual loss)
- painless BOV
- increased myopia
- increased glare (posterior capsular and cortical cataracts)
- moncular diplopia
- altered contrast sensitivity
complications
- secondary uveitis
- lens induced glaucoma
investigations and findings
- no RAPD
- poor visual acuity (BCVA for far and near)
- slit lamp examination (location of cataract (density and type), anterior chamber depth, lens subluxation)
- visual prognosis - direct ophthalmoscope and torch light examination
**direct ophthalmoscope: diminished or loss of red reflex **
torch light examination: obvious yellowing of lens, white pupil (leukocoria)
location and types of cataract
(most common)
* cortical
* nuclear
* subcapsular (posterior and anterior)
all are natural part of aging except anterior subcapsular
PSC found in pts on chronic steroids
indications for cataract surgery
- visually significant cataract causing visual impairment (VA 6/12 or worse, sig glare)
- secondary complications of cataract (narrow angles, lens mechanism related glaucoma, subluxed lens, uveitis)
- blinding retinal disease
1.
considerations before offering surgery
- indication for surgery - severity of visual imparment
- functional impact of cataract - hobbies, job
- lifespan of pt - visual prognosis
- visual requirements of pt - monofocal or multifocal lens
- fit for surgery
types of IOLs
- monofocal IOL
- multifocal IOL
- toric IOL
types of cataract surgeries
- phacoemulsification and foldable IOL inserted through small cornea incision into capsular bag - no sutures, faster recovery, posterior capsule supports IOL within bag
- ECCE (extracapsular cataract extraction) - capsular bag preserved , IOL placed within this bag , larger wound and sutures needed to close
- ICCE (intracapsular cataract extraction) - capsular bag removed , IOL placed either in anterior chamber (ant IOL) or scleral fixated (posterior IOL)
complications of phacoemulsification
- endopthalmitis (sight threatening)
- posterior capsular rupture
- dropped nucleus or nuclear fragment
- suprachoroidal haemorrhage
monofocal IOL
- for distance
- still need to wear reading glasses post op, cannot drive at night
multifocal IOL
for far and near vision
toric IOL
indicated for astig pts - astigmatic correction and reduction
- monofocal: for distance
- multifocal: for far and near, but have bull’s eye vision from new lens, halos
