cataracts Flashcards
what are cataracts?
common eye condition where the lens of the eye gradually opacifies i.e. becomes cloudy. This cloudiness makes it more difficult for light to reach the back of the eye (retina), thus causing reduced/blurred vision. Cataracts are the leading cause of curable blindness worldwide.
what is epidemiology?
Cataracts are more common in women than in men
The incidence of cataracts increases with age. One study found that 30% of individuals aged 65 and over had a visually-impairing cataract in either one or both eyes
causes?
ageing
Smoking
Increased alcohol consumption
Trauma
Diabetes mellitus
Long-term corticosteroids
Radiation exposure
Myotonic dystrophy
Metabolic disorders: hypocalcaemia
features?
GRADUAL ONSET
Reduced vision
Faded colour vision: making it more difficult to distinguish different colours
Glare: lights appear brighter than usual
Halos around lights
what is it?
ens of the eye gradually opacifies i.e. becomes cloudy. This cloudiness makes it more difficult for light to reach the back of the eye (retina), thus causing reduced/blurred vision. Cataracts are the leading cause of curable blindness worldwide
epidemiology?
Cataracts are more common in women than in men
The incidence of cataracts increases with age. One study found that 30% of individuals aged 65 and over had a visually-impairing cataract in either one or both eyes
causes?
ageing
Smoking
Increased alcohol consumption
Trauma
Diabetes mellitus
Long-term corticosteroids
Radiation exposure
Myotonic dystrophy
Metabolic disorders: hypocalcaemia
symptoms?
GRADUAL ONSET
Reduced vision
Faded colour vision: making it more difficult to distinguish different colours
Glare: lights appear brighter than usual
Halos around lights
signs?
A Defect in the red reflex: the red reflex is essentially the reddish-orange reflection seen through an ophthalmoscope when a light is shone on the retina. Cataracts will prevent light from getting to the retina, hence you see a defect in the red reflex.
ix?
Ophthalmoscopy: done after pupil dilation. Findings: normal fundus and optic nerve
Slit-lamp examination. Findings: visible cataract
classifications?
Nuclear: change lens refractive index, common in old age
Polar: localized, commonly inherited, lie in the visual axis
Subcapsular: due to steroid use, just deep to the lens capsule, in the visual axis
Dot opacities: common in normal lenses, also seen in diabetes and myotonic dystrophy
what is non surgical mx?
In the early stages, age-related cataracts can be managed conservatively by prescribing stronger glasses/contact lens, or by encouraging the use of brighter lighting. These options help optimise vision but do not actually slow down the progression of cataracts, therefore surgery will eventually be needed.
what is surgical mx?
Surgery is the only effective treatment for cataracts. This involves removing the cloudy lens and replacing this with an artificial one.
complications post surgery?
Posterior capsule opacification: thickening of the lens capsule
Retinal detachment
Posterior capsule rupture
Endophthalmitis: inflammation of aqueous and/or vitreous humour
