16 - Common eye problems Flashcards
What makes up the retina?
- macula
- choroid
- Bruch’s membrane
- sclera
What is the macula?
- 5mm diameter
- centre of macula is called the fovea
- densely packed with cones and rods
What is the choroid?
- layer of tissue behind retina
- contains blood vessels which oxygenate and bring nutrients to the retina
What is Bruch’s membrane?
Think membrane which forms barrier between choroid and retina
What is the sclera?
Outer thick white layer of eye
What are common eye diseases?
- cataract
- glaucoma
- ARMD
- diabetes
What are the different types of cataracts?
- age related
- congenital
- toxic/drug related
- traumatic
- systemic disease
What are the treatment options for cataracts?
- none
- surgery (phaecoemulsification, intraocular lens implant)
How does cataract affect vision?
Begins with blurring that progressively gets worse until blindness
What is glaucoma?
- most common preventable cause of blindness
- raised intra-ocular pressure
- results in optic neuropathy and visual field defects
Describe a mild glaucoma attack.
- pain in eyes
- haloes around lights
- symptoms are relieved by sleeping
Describe a severe glaucoma attack.
- rapid deterioration of vision
- intense eye pain
- redness and watering of eye
- sensitivity to bright light
- haloes around lights
- nausea and vomiting
What are the treatment options for glaucoma?
- eye drops to reduce flow of fluid (beta blockers)
- laser or surgery to increase draining of fluid (trabeculectomy)
What is ARMD?
- age related macular degeneration
- caused by build up of cellular waste under retina
- affects the central vision (blurring)
What are the different types of ARMD?
- Drusen type
- atrophy (dry)
- neovascularisation (wet)
Describe atrophic ARMD.
- most common form of ARMD
- eyes are dry
- atrophy of photoreceptors at macula
- no treatment available
Describe neovascularisation ARMD.
- atrophic ARMD accompanied by leakage of blood and fluid at macula
- more rapidly progressing
- laser treatment is occasionally effective
- causes visual distortion
What are the treatment options for ARMD?
- none is possible sometimes
- dietary supplements
- activated laser phototherapy
- intravitreal injections (anti-VEGF drugs injected into clear gel that makes up eye volume)
What is involved in diabetic eye disease?
- cataract
- glycemic vessel damage
- leakage, microanneurysms, haemorrhage
- ischaemia
- neovascularisation
What is retinal ischaemia?
- close of retinal capillaries
- most pronounced in the periphery
What is neovascularisation?
Retinal damage due to leakage of weak blood vessels
How does diabetic eye disease affect vision?
Black/blurry patches in vision
How is diabetic retinopathy prevented?
All diabetes require an eye exam annually
How is diabetic eye disease managed?
- improving diabetic control (glycaemia, blood pressure and cholesterol)
- laser
- vitrectomy (replacement of vitreous)
What are common causes of eye redness?
- sticky = bacterial conjunctivitis
- itchy = allergic conjunctivitis
What are causes of acute, painful vision loss?
- keratitis
- uveitis
- acute angel closure glaucoma
- optic neuritis
- endophthalmitis
What are causes of acute, painless vision loss?
- retinal artery or vein occlusion
- ischaemic optic neuropathy
- vitreous haemorrhage
- retinal detachment
What is retinal detachment?
Retinal tear causes retina to detach from sclera
What are causes of chronic, painless vision loss?
- cataract
- refractive error
- open angel glaucoma
- ARMD
- diabetic retinopathy
