Common diseases Flashcards
List the aetiological causes of cataracts (7)
Age related Traumatic Metabolic Toxic Secondary Maternal infection/drug ingestion Hereditary
What are the 3 types of age-related cataracts?
What does each look like?
Subcapsular (ant/posterior*) → granular deposits
Nuclear sclerotic → opaque cloudiness
Cortical → radial spokes
What kinds of traumatic injuries can cause cataracts?
Penetrating eye injury Blunt injury Glass blowers (infrared radiation) Ionising radiation Electric shock
What are the metabolic causes of cataracts (7)
Diabetic (age related earlier + true diabetic (osmotic over hydration)) Galactosaemia Mannodisosis Hypocalcaemic syndromes Fabry's Wilson's Lowe's
What are the toxic causes of cataracts? (3)
Corticosteroids
Chlorpromazine
Chemo
List some secondary causes of cataracts (4)
Anterior uveitis
Hereditary (retinitis pigmentosa, gyrate atrophy, stickler’s)
High myopia
Glaucomflecken
What maternal infections can cause neonatal cataracts?
Rubella (50%)
Toxoplasmosis
CMV
What maternal drug ingestion can cause neonatal cataracts? (2)
Corticosteroids
Thalidomide
What are some causes of presenile cataracts? (2) + 2 presentations/features of each
Myotonic dystrophy - cortical polyhchromatic, post subcapsular stellate
Atopic dermatitis - posterior stellate, dermatitis/no lashes
What are some syndromes associated with cataracts? (4)
Downs
Alports
Werner’s
Rothmund’s
What are the 3 classifications of cataracts?
Immature
Mature (lens totally opaque)
Hypermature (lens wrinkled)
What are the management options for cataracts? (2)
Biometry Surgical (phecoemulsification)
What other factors must be considered when deciding cataract management? (4)
What is NOT a contraindication for surgery
What is an indication/criteria for surgery
Effect on pt’s life (job, ADLs)
General health
Co-existing ocular pathology
Best visual acuity correction
Age not contraindication
Must be mature
What are some possible complications of cataract surgery? (4) + relative incidences
Posterior capsule opacification (20%) Vitreous loss (4%) Retinal detachment (1%) Endophthalmitis (0.1%)
What are the clinical features of acute bacterial endophthalmitis? (5)
What are the common pathogens
Pain Marked vision loss Absent/poor red reflex Corneal haze Hypopyon/exudates
Staph epidermidis, s.Aureus, pseudomonas
What Ix can be done for cataracts? + why would Ix have to be done?
Ocular B scan (USS)
If suspect posterior pole pathology (but view obscured by dense cataract)
What happens in dry AMD? (physiology)
Soft thickenings (Drusens) of Bruch's membrane → atrophy / death of photoreceptors (from RPE → inner choroid)
What happens in wet AMD
Choroidal neovascularisation (inner choroid) These vessels bleed/leak → scarring
What are some RFs for age-related macular degeneration? (5)
Age Smoking CVD (hypertension/lipidaemia) DM Low anti-oxidants in blood
What age group does AMD affect?
How does it present?
> 50s
Blind spots in central vision + visual distortion
What are some of the social effects of AMD? (4)
High falls risk
Difficulty with ADLs
Distress/depression
High use of healthcare/community services
How is AMD treated?
No cure only low-vision aids Wet AMD (CNV): Laser photocoag (not for foveal lesions) (prevent progression + leakage recurs in 50%) Photodynamic therapy Anti-VEGF
Describe the basic pathophysiology behind diabetic retinopathy
And what happens specifically in proliferative?
Retinal vasculopathy of small vessels → leakage +/or closure and seqeulae (VEGF etc released)
Retinal ischaemia → new vessels on optic disc or retinal surface
List the RFs for diabetic retinopathy (8)
Duration of DM Poor DM control Age Smoking Hypertension Hyperlipidaemia Renal impairment Pregnancy
What are the clinical manifestations of Non-Proliferative (Background retinopathy) (6)
Microaneurysms Retinal haemorrhages (dots/flames) Exudates Cotton wool spots Vascular dilations (beading) - severe Intra-retinal anastomoses - severe
What happens structurally regarding neovascularisation in PDR
Originate from veins
Initially flat but raise into vitreous
Fragile/bleed → Vitreous haemorrhage
What are some late changes of proliferative retinopathy? (3)
Retinal detachment / fibrosis
Rubeosis iridis
Neovascular glaucoma
What are the 3 subtypes of proliferative diabetic retinopathy?
And what can be seen on fundoscopy in each?
Focal (retinal thickenings + exudates)
Diffuse (oedema + haemorrhages but no exudates)
Ischaemic (perifoveal capillary network closure → oedema + dark haemorrhages)
What can be used to Dx ischaemic retinopathy
Fluorescin angiography
What are some other effects of DM in the eye? (5)
Higher incidence of infections Delayed healing of infections + corneal abrasions/ulcers Higher incidence of cataracts More severe post-op ocular inflamm Cranial nerve palsies (3/4/6)
How is diabetic retinopathy managed?
Control diabetes + RFs
PDR: laser photocoag (focals/ grid-diffuse / cannot use in ischaemic)
Anti-VEGF
What are some of the modern treatments for age-related macular degeneration? (2)
+ what are their drawbacks
Anti-VEGF: neuroprotective + injections wear off 4-6wks + v expensive
Long-acting steroids (triamcinolone): cause cataracts + raise IOP
What are the main factors affecting IOP ?
Describe the pathology b/wn IOP and glaucoma
Aqeuous production (from ciliary body) Resistance of drainage (trab mesh)
Raised IOP ± vascular factors → optic disc cupping + death/atrophy of retinal nerve fibres
What are the 3 main symptoms of primary open angle glaucoma?
Usually asymp as chronic/slow-progressive
Visual field defects
Tunnel vision
Blindness
What will be seen O/E in primary open angle glaucoma? (3)
+ what investigations can be done? (3)
IOP > 21
Optic disc atrophy (blurring of borders)
Cup:disc ISNT thickness rule lost
IOP (tonometer)
Visual fields
Fundoscopy
What are some RFs for Primary Open Angle Glaucoma (5)
Raised IOP FH** Black race Diabetes Myopia
Describe the pathophysiology behind primary angle closure glaucoma
Lens gradually grows with age → pushes iris closer to trabecular meshwork (+ cuts off at critical point)
What are some RFs for primary angle closure glaucoma?(3)
Narrow angle (smaller lens / shallow anterior chamber) i.e. smaller globes
Hypermetropia (linked to above)
FH
What are the symptoms / signs of acute angle closure glaucoma (6)
In what time scale do symptoms present??
PAIN (eyes + headache)
Blurred vision
Red eye
Vomiting (severe)
Corneal oedema
Fixed mid-dilated pupil
Symps may be present for wks before attack (going to bed helps as pupil dilates + pulls away)
How is acute angle closure glaucoma managed?
Urgent management (3)
Long-term management
Urgent IV carbonic anhydrase inhibitor (acetazolamide)
(Analgesia + anti-emetics)
Wait 1hr
Pilocarpine eye drops (every 5mins)
Laser iridotomy
Trabeculectomy
What are some secondary causes of glaucoma? (3)
III Advanced
Neovascular: central vv occlusion / DR (→ rubeosis iridis)
Uveitic: inflamm/steroids
Traumatic: blunt/penetrating
Injury/Inflamm/Iatrogenic
Advanced cataracts/diabetes
List the medical management options of glaucoma (mainly POAG) (5)
How does each lower IOP
Prostaglandin analogues (latanaprost) Beta-blockers (timolol) Carbonic anhydrase inhibs (drops/p.o.) (dorzolamide) Alpha agonist (brimonidine) Cholinergic (pilocarpine)
List the SEs of each medical treatment of glaucoma (5)
Prostaglandins - thick lashes, pigmentation
Beta - cardiac/resp effects
Carbonic anhydrase inhibs - taste probs, acidosis
Alpha - dizziness, syncope, allergy
Cholinergic - eye ache + poorest compliance
What is done in a laser iridotomy (trabeculoplasty)?
Who is it done in?
Shots around trabecular meshwork
All age groups (primary treatment) + with open-angle
What is done in a trabeculectomy?
What are its main disadvantages? (2)
Creates controlled fistula where aqueous leaks out under conjunctiva
Open pathway for infection Treatment failure (when conjunctival tissue activates/scars)
What are the RFs for a trabeculectomy failing? (5) (PMH/DH)
Previous eye surgery Black race Diabetes (esp w. retinopathy) Long-term topical medications (e.g. pilocarpine) Coexisting/past uveitis
What are the obvious features of intraocular foreign body?
+ important things to check
What Ix are done
Sudden onset irritation + photophobia (±vision loss)
NB ask exact mechanism + check under eyelid
X-Ray/CT
How is ocular chemical injury managed? (4)
Urgently irrigate w. saline (litres)
Determine substance type
Compare pH for both eyes (alkaline worse)
Abx/VitC/Steroids/Mydriatics
List some complications of blunt ocular trauma? (8)
Peri-orbital haematoma
Sub-conjunctival haemorrhage
Hyphaema (+ acute glaucoma)
Traumatic cataracts Lens dislocation (zonule rupture)
Retinal tear/detachment
Extensive retinal haemorrhage - v v severe
Vitreous haemorrhage- v v severe
What is a blow out fracture + what features would present? (2)
List a complications
Weak orbital floor fracture + eye thru floor into maxillary sinus
Restriction of eye movements
Periorbital swelling
Inferior rectus can get trapped/ischaemic if not released
What investigations are done in a blow-out fracture (2)
X-Ray (checking opacification of sinus) (not Dx)
CT (for conclusive)
