Opthalmology Flashcards
Gradual loss of vision: DDx
- Cataract
- Macular degeneration
- Diabetic retinopathy
- Hypertensive retinopathy
- Chronic glaucoma
- Optic nerve compression / damage
- Global - trachoma (chlamydia)
Red eye: DDx
- Glaucoma
- Conjunctivitis
- Uveitis
- Sub conjunctival haemorrhage
- Corneal abrasion / ulcer
Sudden loss of vision: DDx
- Vitreous haemorrhage
- Retinal detachment
- Central retinal artery occlusion
- Central retinal vein occlusion
- Temporal arteritis
Optic atrophy (pale optic discs): DDx
- Glaucoma
- Ischaemia - stroke, vasculitides (temporal arteritis)
- Inflammation - optic neuritis (MS)
- Drugs - ethambutol, etoh
- Tumour compressing optic nerve
- Congenital aplasia of optuc nerve
- Hereditary optic neuropathy (Leber’s)
Swollen discs on fundoscopy: DDx
- Papilloedema (optic disc swelling caused by raised ICP)
- SOL
- Intracranial bleed
- Venous sinus thrombisis
- Aqueductal stenosis
- Optic atrophy (in acute stage)
- Glaucoma
- Ischaemia - stroke, vasculitides (temporal arteritis)
- Inflammation - optic neuritis (MS)
- Drugs - ethambutol, etoh
What are the characteristics of diabetic retinopathy on fundoscopy?
- Background: hard exudates, (dots) microaneurysms, blot haemhorrhages
- Pre-proliferative: cotton wool spots (retinal ischaemia), macular oedema
- Proliferative: neoangiogenesis
(Meeran)
How is diabetic retinopathy classified based on fundoscopic appearance?
Non-proliferative diabetic retinopathy:
- Mild: Indicated by the presence of at least 1 microaneurysm
- Moderate: Includes the presence of hemorrhages, microaneurysms, and hard exudates
- Severe (4-2-1): Characterized by hemorrhages and microaneurysms in 4 quadrants, with venous beading in at least 2 quadrants and intraretinal microvascular abnormalities in at least 1 quadrant
Proliferative diabetic retinopathy:
- Neovascularization: Hallmark of PDR
- preretinal hemorrhages, hemorrhage into the vitreous, retinal detachments, macular oedema
(Emedicine)
What are the clinical / fundoscopic stage of macular degeneration?
- Early - macular pigmentary changes, <63um drusen (lipid deposits under retina), normal / near-normal vision
- Intermediate - 63-125 um drusen
- Late - >125um drusen, decreased central vision
(BMJ)
Summarise the epidemiology of macular degeneration
3rd most common cause of visual impairment
Incidence increases with age
UK Prevalence 2.4% total, 4.8% >65y, 12.2% >80y
(BMJ, UpToDate)
Explain the risk factors of macular degeneration
Strong RFS: age, FHx, smoking, cataract surgery
Weak RFs: CV disease, obesity, HTN, genetic
(BMJ)
Identify appropriate investigations for macular degeneration
Eye testing: Amsler grid (look at grid, any subjective change? ie distortions or dark areas
Imaging: optical coherence tomography (test for subretinal / intraretinal fluid)
(BMJ)
Generate a management plan for macular degeneration
- Conservative
- Observation + specialist referral
- Risk factor modification (stop smoking, balanced diet
- Medical
- if intermediate: high dose antioxidant (‘AREDS’ formulation)
- if severe exudative:
- intravitreal injection with vascular endothelial growth factor inhibitors
- thermal laser photocoagulation
(BMJ)
Identify the possible complications of macular degeneration
Short: injection-related endopthalmitis / retinal detachement / lens trauma
Long: laser-related photosensitivity, progression of AMD (–> blindness)
(BMJ)
Summarise the prognosis for patients with macular degeneration
Morbidity: progression
5y risk of progression 1.3% if early, 18% if intermediate, 43% if severe
(BMJ)
What is glaucoma? What are the different types?
Impaired drainage of the aqueous humour through the trabecular network –> build up –> increased intra ocular pressure (not always) –> optic nerve damage
- Open-angle: normal anatomical angle between the iris and cornea, implying the obstruction to aqueous humour outflow is within the trabecular network. Most common form. –> increased intraocular pressure –> peripheral vision loss, then central vision loss
- Closed-angle: narrowed angle between the iris and cornea (due to lens pushing forward) impairs aqueous humour drainage into the trabecular network. –> rapid increase in intraocular pressure –> rapid-onset eye pain, eye redness, blurred vision, headaches, nausea
- Normal-tension: like open-angle glaucoma but with normal intraocular pressure (11-21 mmHg)
Explain the risk factors of glaucoma
Open angle
- Strong RFs: raised intraocular prressure, age>50, FHx glaucoma, black ethnicity
- Weak RFs: mypopia, DM, HTN
Closed angle:
- Strong RF: female, hyperopia, shallow peripheral anterior chamber, PMH angle closure glaucoma, asian ethnicity
- Weak RFs: elderly, FHx, drugs that induce angle narrowing (Local; atropine. Systemic; sulfonamides, phenothiazines)
(BMJ)
Identify appropriate investigations for glaucoma
Slit lamp examination (look for optic nerve damage)
Tonometry (measure intraoccular pressure)
Optical coherence tomography (of angle + retina, test for angle closure
Generate a management plan for glaucoma (closed angle vs open angle)
Closed-angle
- Acute
- Medical:
- 1st line: carbonic anhydrase inhibitor (acetazolamide) and/or topical beta-blocker (tomolol drops) and/or topical alpha2-agonist (brimonidine)
- cholinergic agonist (pilocarpine)
- hyperosmotic agent (mannitol IV)
- 2nd line: anterior chamber paracentesis
- 1st line: carbonic anhydrase inhibitor (acetazolamide) and/or topical beta-blocker (tomolol drops) and/or topical alpha2-agonist (brimonidine)
- Medical:
- Chronic: laser peripheral iridotomy (alleviates block by allowing aqueous humour to bypass pupil)
Open-angle
- Acute:
- Medical:
- 1st line: topical prostaglandin analogues (lanaprost)
- or carbonic anhydrase inhibitor / topical beta-blocker / alpha2-agonist (as above)
- 2nd line: laser trabeculoplasty
- 1st line: topical prostaglandin analogues (lanaprost)
- Surgical:
- Trabeculectomy or aqueous shunt (create passage for aqueous humour drainage)
- Medical:
(BMJ)
Identify the possible complications of glaucoma
Short: retinal vein occlusion, fellow eye attack
Long: optic atrophy (peripheral vision loss, then central)
Generate a management plan for conjunctivitis
Management of infective conjunctivitis
- Conservative: self-limiting, usually settles w/i 1-2w, take out contact lenses, don’t share towel, school exclusion not necessary
- Medical:
- topical chloramphenicol (drops /3h) or topical fusidic acid (in pregnancy, BD)
Management of allergic conjunctivitis
- topical or systemic antihistamines
- topical mast-cell stabilisers, e.g. Sodium cromoglicate and nedocromil
(passmedicine)
Give causes of a complex opthalmoplegia
- Grave’s disease (exopthalmos)
- Myasthenia gravis
- Orbital Guillain-Barre Syndrome (Miller-Fischer Syndrome)
- Retro-orbital tumour
(Meeran)
How is proliferative retinopathy managed?
Either
- Panretinal photocaogulation (laser ablation of periphery to prevent new vessels bleeding into vitreous –> blindness. Preserves macular)
Or
- anti-VEGF injections (needed regularly, expensive)
- (Meeran)*
What are the main features of Refsum’s Disease?
Retinitis pigmentosa + cerebellar ataxia + peripheral neuropathy + rasied CSF protein
+/- anosmia, arrhytmias, ichythosis (fishscale skin)
Onset in young adults
What are the fundoscopic characteristics of hypertensive retinopathy? (Graded)
- Grade 1: silver wiring (borderline HTN)
- Grade 2: AV nipping
- Grade 3: cotton wool spots + flame haemorrhages
- Grade 4: papilloedema
(Meeran)
