KEY OPHTHALMOLOGY Flashcards
What is glaucoma?
Optic nerve damage caused by a significant rise in IOP.
Pathophysiology in open angle glaucoma?
Gradual increase in resistance through trabecular meshwork
More difficult for aqueous humour to pass through
Pressure slowly builds
Pathophysiology in acute angle closure glaucoma?
Iris bulges forwards and seals off trabecular meshwork
Prevents aqueous humour from being able to drain away
Leads to continual build up of pressure
Effect of increased IOP on optic disc?
Cupping of optic disc.
Presentation of open angle glaucoma?
Asymptomatic for a long time. Affects peripheral vision (leads to tunnel vision) Fluctuating pain + headaches Blurred vision Haloes around lights
Gold standard way to measure IOP?
Goldmann application tonometry
Management of open angle glaucoma?
1st line = prostaglandin eye drops (Latanoprost).
2nd line = timolol, carbonic anhydrase inhibitors, sympathomimetics.
3rd line = trabeculectomy.
When is treatment of open angle glaucoma usually started?
At an IOP of 24mmHg or above.
MoA of Latanoprost (prostaglandins eye drops)?
Increase uveoslceral outflow.
SEs: eyelash growth, eyelid pigmentation, iris pigmentation (browning).
MoA of Timolol?
Reduce production of aqueous humour.
MoA of Carbonic anhydrase inhibitors?
Reduce production of aqueous humour.
MoA of sympathomimetics?
For example, Brimonidine.
Reduce production of aqueous fluid + increase uveoscleral outflow.
Surgical option for open angle glaucoma?
Trabeculectomy if eyedrops options are ineffective.
Medications which can precipitate acute angle closure glaucoma?
Adrenergic medications (noradrenaline) Anticholinergic medications (Oxybutynin) TCAs
Acute angle closure glaucoma presentation?
Severely painful red eye
Blurred vision
Haloes around lights
Headache, nausea + vomiting
Signs of angle closure glaucoma?
Red, teary eye Hazy cornea Decreased visual acuity Dilatation of affected pupil Fixed pupil size Firm eyeball on palpation
Initial management of acute angle closure glaucoma?
Pilocarpine (2% for blue eyes, 4% for brown)
Acetazolomide
Analgesia + antiemetic if required.
Secondary care management of acute angle closure glaucoma?
Pilocarpine Acetazolomide Hyperosmotic agents (glycerol/ mannitol) Timolol Dorzolamide Brimonidine
MoA of hyper osmotic agents (glycerol/ mannitol)?
Increase osmotic gradient between blood and fluid in the eye.
MoA of pilocarpine?
Acts on muscarinic receptors to cause constriction of the pupil.
MoA of acetazolamide?
Carbonic anhydrase inhibitor which reduces production of aqueous humour.
Surgical management option for definitive management of acute angle closure glaucoma?
Laser iridotomy
Management dry age related macular degeneration?
Lifestyle measures
Management in wet age related macular degeneration?
Anti-VEGF medications (Ranibizumab/ bevacizumab/ pegaptanib).
**These are injected directly into the vitreous chamber.
Two categories of diabetic retinopathy?
Proliferative and non-proliferative.
Findings in non-proliferative diabetic retinopathy?
Mild - micro aneurysms
Moderate - micro aneurysms, blot haemorrhages, hard exudates, cotton wool spots
Severe - blot haemorrhages + micro aneurysms in 4 quadrants.
Findings in proliferative retinopathy?
Neovascularisation
Vitreous haemorrhage
Findings in diabetic maculopathy?
Macular oedema
Ischaemic maculopathy
Management of diabetic retinopathy?
Photocoagulation
Anti-VEGF
Vitreoretinal surgery
Stage 1 hypertensive retinopathy?
Mild narrowing of arterioles
Stage 2 hypertensive retinopathy?
Focal constriction of blood vessels
AV nipping
Stage 3 hypertensive retinopathy?
Cotton wool patches
Hard exudates
Flame haemorrhages
Stage 4 hypertensive retinopathy?
Papilloedema
Presentation of cataracts?
Very slow reduction in vision
Progressive blurring
Change in colour vision (colours more yellow/ brown)
Starbursts appearing around lights, particularly at night time
Rare but serious complication of cataract surgery?
Endophthalmitis
Cause of blepharitis?
Dysfunctional meibomian glands.
Blepharitis presentation?
Inflammation of eyelid margins.
Gritty, itchy and dry sensation in the eyes.
Management of blepharitis?
Hot compresses + gentle cleansing of the eyelid margins to remove debris.
What is entropion?
Eyelashes turn inwards.
What is ectropion?
Outwards turning of the eyelid.
What is periorbital cellulitis?
Infection of eyelid and skin in front of orbital septum.
What is orbital cellulitis?
Infection around eyeball involving tissues behind orbital septum.
Features that differentiates orbital cellulitis from periorbital cellulitis?
Orbital cellulitis = pain on eye movement, reduced eye movements, changes in vision, abnormal pupil reactions and forward movement of the eyeball.
3 causes of painless red eye?
Conjunctivitis
Episcleritis
Subconjunctival haemorrhage
Pathognomonic findings of anterior uveitis?
ciliary flush (red spreading from cornea outwards)
photophobia
abnormally shaped pupil
