Cataracts Flashcards
define cataracts
where the lens becomes cloudy and opaque
this reduced visual acuity by reducing the light that enters the eye
describe the function of the lens
-how is it nourished
focus light coming into the retina
-nourished by surrounding fluids and doesn’t have a blood supply
how is the lens held in place
by suspensory ligaments attached to the ciliary body
how does the ciliary body function
contracts and relaxes to focus the lens
when it contracts it releases tension on the suspensory ligaments and the lens thickens
when it relaxes it increases the tension in the suspesnory ligaments and the lens narrows
types of cataracts
most develop over years with advanced age in presence of risk factors
congenital cataracts occur before birth
how are congenital cataracts screened for
with red light reflex during neonatal examination
risk factors for cataracts 6
increasing age
smoking
alcohol
diabetes
steroids
hypocalcaemia
syx of cataracts 4
usually asymetrical as both eyes are affected separately
presents with:
-very slow reduction in vision
-progressive blurring of vision
-change of colour of vision with colours becoming brown or yellow
-‘starbusts’ can appear around lights, particularly at night time
key sign of cataracts
loss of red reflex
-lens appears grey or white when testing the red reflex
describe the basic presentation of the following common eye conditions:
-cataracts
-Glaucoma
-macular degeneration
cataracts- generalised reduction in visual acuity with starbursts around lights
glaucoma- cause peripheral loss of vision with halos around lights
macular degeneration -causes central vision loss with a crooked or wavy appearance to straight lines
management of cataracts
if syx manageable no intervention necessary
cataract surgery
important point about cataract surgery
before surgery cataracts can prevent the detection of other pathology like macular degeneration or diabetic retinopathy
therefore after surgery they may still have poor visual acuity due to other problems
process of cataract surgery
drilling and breaking lens into pieces
removing the pieces and implatning an artificial lens into the eye
usually done as day case under LA and gives good results
name an important rare complication of cataract surgery
endophthalmitis
define endophthalmitis
inflammation of the inner contents of the eye usually caused by infection
-can be treated with intravitreal antibiotics injected into the eye and can lead to loss of vision and loss of eye itself
