Cataract Flashcards
What is a cataract?
Opacification of the lens of the eye causing a gradual loss of the vision
What are the three types of cataract?
Nuclear sclerosis (central lens) Cortical (outer lens) Posterior subscapsular (back of the lens)
What are some risk factors for cataract?
Increasing age
Secondary to ocular disease- e.g. post inflammatory (uveitis and posterior subcapsular cataract)
Trauma- can cause an acute cataract
Drug induced- steroid increase the risk of developing posterior sub-capsular cataract)
Congenital cataract
What are the symptoms?
Clouding of vision
Haloes around light
Progressive loss of vision
Glare
What may be seen on examination?
Grey/white ish pupil using a pen torch
Reduced red reflex
Nuclear Sclerosis can cause a yellow/brown cataract
What is the most common cause of cataract
Nuclear sclerosis
What type of cataract is associated with steroids and uveitis?
Posterior sub-capsular
Where does nuclear sclerosis affect?
Centre of the lens
Where does cortical cataract effect?
The outer lens
Where does posterior sub-capsular affect?
The back of the lens
When should intervention be considered for cataract?
When the reduced visual acuity begins to restrict normal activity.
Note- Younger patients may require surgery sooner
Diabetic patients need to have cataracts removed so that the back of the eye can be examined annually.
What is the surgery for cataract?
Surgical replacement- removal by phakoemulsification (Ultrasound) and replacement with an artificial lens
What are some complications of cataract operation?
Endopthalmitis- mainly due to contamination from eye lashes.
Rupture of the posterior capsule leading to vitreous loss (artificial lens usually rests on posterior capsule)
Haemorrhage
Opacification of posterior lens capsule
Retinal detachement
What can be done for posterior capsule opacification after cataract operation?
Yag Laser used to make a hole in the capsule
