Pathology of the Eye Flashcards
What are the worldwide causes of blindness/SSI (severely sight impaired)
- Cataract (most common cause of blindness),
- Uncorrected refractive error (most common cause of sight impairment),
- Age related macular degeneration,
- Diabetic retinopathy,
- Glaucoma,
- Corneal opacities
80% is avoidable or treatable
What are the cataract risk factors?
Age, diabetes, trauma, inflammation, steroid use, UV/radiation and congenital.
What are the risk factors for corneal ulcers and how are they treated?
Contact lenses, varicella/herpes, steroid drop use, dry eyes/exposure and trauma or burns. Treated with corneal transplant
Why do you get an abnormal fundal reflex?
When there is anything obstructing the path of light from the front to the back of the eye. Sinister cause is retinoblastoma
why does blindness occur in diabetic retinopathy?
- Growth of new vessels which can cause vitreous haemorrhage, tractional retinal detachment and glaucoma.
- Leakage of fluid from damaged vessels can cause macular oedema with loss of central visual acuity
What is the treatment for diabetic retinopathy?
Lifestyle - smoking cessation, weight control and encourage exercise.
Blood sugar/pressure/cholesterol control.
Support renal function.
Laser, anti-VEGF or surgery.
What is the pathogenesis of diabetic retinopathy?
Increased glucose results in;
- Non-enzymatic glycation,
- Oxidative stress,
- Aldose-reductase activation,
- Diacylglycerolproteinkinase C activation.
Which causes microvascular endotheliopathy which causes an increase in permeability, neovascularisation and capillary occlusion which causes retinopathy
What is retinopathy of prematurity?
Potentially blinding disorder if left untreated. Occurs in premature new-borns. The pathological mechanism is similar to diabetic retinopathy.
What are the two types of age-related macular degeneration?
Dry and wet
What are the symptoms of age related macular degeneration?
Progressive reduction in visual acuity. If metaphorphopsia is present then it may indicate wet type.
What is the treatment of age-related macular degeneration?
Prevention, rehabilitation and anti-VEGF injections
What is glaucoma?
Optic neuropathy with a caracteristic visual feild defect. It is most commonly associated with raised intraocular pressure and is treated with drops or surgery.
What are the causes of swollen optic disks?
Psudo swelling - Small discs or drusen.
Genuine swelling - Raised ICP, SOL, IIH or hydrocephalus
What are the symptoms of raised intracranial pressure?
Headaches which are worse when beinding foreward, vomiting/nausea, visual disturbances, tinnitus, confusion, pupillary abnormalities and diplopia
Name the 6 extraocular muscles
- Medial and lateral recti,
- Superior and inferior recti,
- Superior and inferior oblique
