Ophthalmology Flashcards
What is a cataract?
Opacification of the proteins in the lens of the eye leading to loss of visual acuity
Give 3 causes of cataracts
Old age UV light Trauma Smoking Alcohol Diabetes Metabolic disorders Uveitis Steroids Congenital
What are the symptoms of cataract?
Painless loss of vision
Misting/blurring
Change in refractive error
Give 2 examples of common complaints a patient with cataract may express
Difficulty reading
Difficulty recognising faces
Difficulty driving at night
Halos around lights
What 2 conditions may cause halos around lights?
Cataract
Glaucoma
What features may be seen on examination of a patient with cataract
Reduced visual acuity
Reduced red reflex
How are cataracts managed?
Surgery (vision worse than 6/12) - phaecoemulsification with synthetic lens replacement
What should a patient be informed about regarding the recovery period for cataract surgery?
Eye patch for 24 hours
Avoid driving, swimming and heavy lifting for 5 days
Steroids, antibiotics and dilating drops may be prescribed
What are the contraindications to cataract surgery?
Diabetic retinopathy
Intraocular inflammation
What are the complications of cataract surgery?
Posterior capsule opacification Choroidal haemorrhage (bleeding) Endophthalmitis (infection) Glaucoma Vitreous loss Visual disturbance Retinal detachment
What is posterior capsule opacification and how is it managed?
Cloudy layer of scar tissue (residual lens epithelial cells) at the back of the lens capsule after replacement
YAG laser capsulotomy
What is the most common complication of cataract surgery?
Posterior capsule opacification
What do phakic, pseudophakic and aphakic mean?
Phakic - natural lens
Pseudophakic - natural lens removed and artificial lens inserted
Aphakic - natural lens removed but not replaced
Other than treatment of cataract, what other reasons may a patient undergo cataract surgery?
Treatment of angle closure glaucoma
Improve visualisation of retina to manage co-morbidity (e.g. diabetic retinopathy)
What is biometry?
Measurement of corneal curvature and length of the eye prior to cataract surgery to allow selection of the most appropriate intraocular lens implant
Name 3 types of cataract and their cause
Nuclear sclerotic - age, yellow/white
Posterior subcapsular - steroids and diabetes, inflammation
Congenital - inherited or idiopathic, amblyopia
Traumatic - blunt/penetrating trauma
What is glaucoma?
Gradual death of the optic nerve due to high intraocular pressure, usually due to an imbalance in the production and drainage of aqueous humour
Where is aqueous humour produced and drained?
Produced - ciliary body
Drained - irido-corneal angle -> trabecular meshwork -> canal of Schlemm
What is open angle (chronic) glaucoma?
Defect of the trabecular meshwork slows down the flow of aqueous humour which increases ocular pressure leading to optic nerve damage and gradual vision loss
What is closed angle (acute) glaucoma?
Narrowing of the irido-corneal angle which prevents aqueous fluid drainage, leading to rapid rise in ocular pressure and damage to the retina via stretching and decreased blood supply
Which type of glaucoma is most common?
Open angle
What are the risk factors for open angle glaucoma?
Family history Age Black ethnicity Thin cornea Large vertical nerve cupping High ocular pressure
How is open angle glaucoma screened for?
Strong family history - screening every 2 years from age 30
Otherwise - every 5 years from age 40 and 2 years from age 60
What are the symptoms of open angle glaucoma?
Gradual peripheral visual loss - patient may not be aware of this
Give 2 features of open angle glaucoma seen on examination
Elevated pressure
Optic disc changes - increased cupping, haemorrhage, thinning and notching of rim, optic atrophy
Peripheral visual loss - central spared
What is a normal ocular pressure? When is it at its highest normally?
10-22 mmHg
Morning
How is ocular pressure measured and how is it affected by corneal thickness?
Tonometer
Thin cornea = lower reading than actual value
Thick cornea = higher reading than actual value
How is open angle glaucoma managed medically?
Topical beta-blocker (timolol) - decrease aqueous production
Prostaglandin analogues (latanoprost)- increase aqueous outflow
Carbonic anhydrase inhibitor (brinzolamide) - decreased production
Alpha 1 agonist (brimonidine) - both
How is open angle glaucoma managed surgically?
Trabeculectomy - with mitomycin C
Laser trabeculoplasty - burn meshwork/ciliary body to increase aqueous outflow/decrease aqueous production
Shunt - Molteno tube, Ahmed valve
What are the symptoms of acute angle closure glaucoma?
Extremely red and painful eye
Associated nausea and vomiting
Halos around light
What features may be seen on examination of acute angle closure glaucoma?
Sluggish dilated pupil
Elevated pressure (>60mmHg)
Rock hard eye on palpation
How is acute angle closure glaucoma managed medically?
Topical - pilocarpine (reduces pressure)
Systemic - IV acetazolamide
How is acute angle closure glaucoma managed surgically?
YAG laser iridotomy - create communication between anterior and posterior chambers to relieve pressure gradient
Both eyes, even if only 1 was affected
What is the ISNT rule?
Pattern of neural rim width
(thickest) I - inferior rim S - superior rim N - nasal rim T - temporal rim (thinnest)
This rule is lost in glaucoma
What investigations can be done for glaucoma?
Tonometer Slit lamp Visual fields (scotoma) OCT optic disc Gonioscopy
What are the complications of trabeculectomy for open angle glaucoma?
Hypotony
Infection
Cataract
Bleb leakage
What populations are at higher risk of acute angle closure glaucoma?
Elderly
Hypermetropic (abnormal ability to focus of distant objects; far-sightedness)
Chinese ethnicity
Give 3 features of congenital glaucoma
Large, watering photophobic eyes Increased corneal diameter Cloudy cornea Reduced vision Raised pressure Treatment - goniotomy, trabeculotomy
How does neovascular glaucoma occur?
Diabetic retinopathy or retinal vein occlusion
VEGF produced from ischaemic retina which leads to neovascularisation of iris
Fibrous membrane forms over trabecular meshwork which closes drainage angle
Needs surgery
What is pigment dispersion syndrome?
Occurs in young caucasian myopic (near-sighted) males
Pigmented iris rubs against zonules -> pigment sheds and clogs meshwork
Can be caused/worsened by exercise
What is pseudoexfoliation syndrome?
Systemic disorder in which a fibrillar, proteinaceous substance is produced in abnormally high concentrations within ocular tissues
What are the 2 types of macular degeneration?
Dry/atrophic (slow decline)
Wet/exudative (rapid decline)
What are the risk factors for macular degeneration?
Age >55 Smoking Family history Diabetes Previous history of macular degeneration in other eye
What type of macular degeneration is more common?
Dry
What are the symptoms of macular degeneration?
Decline in visual acuity - central vision, distortion (e.g. of lines)
What may be seen on examination of macular degeneration?
Normal visual fields
Reduced visual acuity
No pupillary defect
What investigation can be done for macular degeneration and what features will be seen in dry and wet types?
Fundoscopy/retinal imaging
Dry - drusen, atrophy of retina, darker macula
Wet - scarring and haemorrhages, neovascularisation
How is dry macular degeneration managed?
No treatment
High dose vitamins
Smoking cessation
Annual eye examination
How is wet macular degeneration managed?
Anti-VEGF injections into the eye
Laser therapy to target new blood vessels
What are the main features of central retinal vein occlusion?
Sudden painless loss of vision (central) Unilateral Vision not improved with pinhole May have RAPD if severe Elderly
What signs may be seen on examination of CRVO?
Hyperaemic retina with engorged veins Swollen optic disc Multiple haemorrhages Cotton wool spots 'Stormy sunset' appearance
What are the causes of CRVO?
Raised ocular pressure (glaucoma, HTN)
Hyperviscosity (polycythaemia)
Vessel wall disease (diabetes, sarcoidosis, hyperlipidaemia)
How is CRVO managed?
No treatment needed - address cause and CV RFs
Fibrinolysin/laser therapy may be useful
What is central retinal artery occlusion?
‘Stroke of the retina’
How does CRAO present?
Sudden painless loss of vision
Unilateral
Curtain across vision
What features may be seen on examination of CRAO?
RAPD
Reduced visual acuity (no perception of light)
Ophthalmoscopy - retinal emboli, may be normal, pale retina with cherry red spot (macular sparing due to supply from posterior ciliary artery)
What should be ruled out in CRAO and how?
Temporal arteritis - ESR
What are the causes of CRAO?
Arterial embolus from carotid/valvular heart disease/AF
Temporal arteritis
Vasculitis (polyarteritis nodosa)
Atherosclerosis (diabetes, HTN)
How is CRAO managed?
<30 minutes from onset - globe massage to dislodge embolus
Rebreath CO2 (paper bag)
IV acetazolamide - reduce pressure
Bloods - ESR
What is amaurosis fugax?
‘TIA of the retina’
Transient loss of vision due to temporary occlusion of retinal artery
Give 4 causes of sudden painless loss of vision
Retinal detachment Vitreous haemorrhage CRVO Amaurosis fugax CRAO Wet AMD Posterior vitreous detachment
How does retinal detachment present?
Sudden painless loss of vision
Flashing lights, floaters, visual field defects
Classic curtain over vision
Macular involvement = central vision affected
What features may be seen on examination of retinal detachment?
RAPD
Abnormal red reflex
May be able to visualise fold in eye
May be normal
In what patients are retinal detachments more common?
Myopic (near-sighted)
Diabetic retinopathy
Previous surgery (e.g. cataracts)
What is the main differential for retinal detachment?
Posterior vitreous detachment
How is retinal detachment managed?
Minor - laser to encourage inflammation and healing
Major - retinal surgery +/- vitrectomy
Give 4 causes of a red eye
Conjunctivitis Corneal abrasion Corneal ulceration Anterior uveitis Episcleritis Scleritis Subconjunctival haemorrhage
What are the symptoms of conjuncivitis?
Gritty irritation Itchiness Discharge Injection Normal vision (improved on pinhole if mildly reduced)
What are the causes of conjuncitivis and their defining features?
Bacterial - purulent sticky discharge
Viral (e.g. adenovirus, HSV) - watery discharge, lymphoid follicles on conjunctiva, pre-auricular lymphadenopathy
Allergy - itchy, watery
How are bacterial, viral and allergic conjunctivitis managed?
Bacterial - antibiotics
Allergic - self-resolving, anti-histamines
Viral - lubricating eye drops, frequent cleaning, hygiene measures
What symptoms should be asked about in a patient presenting with a red eye?
Blurred vision Sticky/gritty/discharge Photophobia Pain/halo/headache/vomiting Discomfort/dryness Foreign body sensation Redness/swelling Itch Watering Hearing loss/jaw claudication
How should a red eye be examined?
Visual acuity (plus pinhole) External examination Slit lamp - fluoroscein, topical anaesthetic, eversion of eyelids Pupils Eye movements
What is chemosis?
Swelling/oedema of the conjunctiva
What features can be seen on eversion of the eyelids? What types of conjunctivitis do they correspond to?
Papillae - cobblestoned nodules; bacterial, allergic
Follicles - lymphoid hyperplasia; viral
What is trachoma?
Most common infectious cause of blindness
Repeated episodes of infection with chlamydia trachomatis in childhood lead to severe conjunctival inflammation, scarring, and potentially blinding in-turned eyelashes (trichiasis or entropion) in later life
What is the difference between a corneal ulcer and abrasion?
Ulcers involve the stroma and are opaque and uneven
Give 3 features of bacterial keratitis
Rapid onset Contact lens user, dry eyes, abrasion Pain, foreign body sensation, reduced vision, photophobia Round/oval white lesion Lasts 7-14 days
Give 3 features of viral keratitis
Insidious onset History of cold sores/feeling run down Pain, irritation, reduced vision Dendritic appearance (HSV), raised IOP Lasts <7 days
Give 3 features of fungal keratitis
Onset over several days
Outdoors, vegetative trauma
Pain, photophobia, red eye, reduced vision
Feathery edges, satellite lesions, necrotic slough
Lasts 1-2 months
What are the risk factors for corneal ulcers?
Trauma Contact lens use Ocular surface disease (e.g. dry eyes, blepharitis, corneal anaesthesia) Lid disease (e.g. entropion) Systemic condition (e.g. RA, DM)
What are the symptoms of corneal ulcers?
Pain Foreign body sensation Redness Photophobia Tearing Discharge Reduced vision Injection Single/multiple white foci Hypopyon
What are the complications of corneal ulcers?
Scleral extension
Corneal perforation
Endophthalmitis
Corneal scarring
What investigations can be carried out for a corneal ulcer?
Corneal scrape (>1mm) Contact lenses - send lenses, solution and case for culture Swabs - viral PCR
How is HSV keratitis/dendritic ulcer managed?
Aciclovir ointment
How are corneal ulcers managed before a cause is know?
Empirical antibiotic therapy (e.g. cefuroxine and gentamicin)
Cyclopentolate (dilate pupil to reduce photophobia)
What are the symptoms of scleritis?
Acute red eye
Pain on eye movement
Globe tenderness
Severe pain - keeping patient up at night
How is scleritis managed?
Oral steroids
Investigation of cause/vasculitis
What are the symptoms of episcleritis?
Diffuse or sectoral red eye
Mild pain
Self-limiting
How is episcleritis managed?
Topical NSAIDs
Topical steroids
What is uveitis?
Inflammation of the uveal tract (iris, ciliary body, choroid) and neighbouring structures
How is uveitis classified?
Based on anatomical location
Anterior, intermediate, posterior, panuveitis
What causes uveitis?
Idiopathic (50%) Trauma Infection Autoimmune (e.g. RA) Neoplastic
What are the symptoms of uveitis?
Anterior - photophobia, redness, watering, pain, reduced vision
Intermediate - reduced vision, floaters, photopsia
Posterior - reduced vision, floaters, photopsia, scotoma
What features may be seen on examination of uveitis?
Limbal injection (circumcorneal) Anterior chamber (AC) cells AC flare Posterior synechiae Keratic precipitates (KP’s) (mainly inferiorly) \+/- fibrin and hypopyon
What are the complications of uveitis?
Raised IOP
Cataract
Cystoid macular oedema
Optic neuropathy
Why is a systemic review important in uveitis?
May give clues to underlying cause Joint pain/swelling/back pain - ank spond, RA, JIA Cough - TB, sarcoid Rash - sarcoid, Behcets Diarrhoea - IBD (crohns/UC) Dysuria - Reiters IV Drug use, sexual history - HIV Immunocompromised - CMV Recent Travel - TB
How is uveitis managed?
Treat cause if known
Anterior - topical steroids and cyclopentolate
Intermediate - as above
Posterior - systemic steroids (if infectious cause ruled out)
What ocular issues may result from trauma?
Foreign body Abrasions Lacerations Hyphaema Penetrating trauma Retrobulbar haemorrhage Orbital wall fracture
What is a corneal abrasion?
‘Scratch on eye’
Defect in epithelium
How is corneal abrasion managed?
Chloramphenicol ointment 4x day for 3 days
How is a foreign body managed?
Topical anaesthetic and use a green needle to remove
Chloramphenicol ointment 4x day for 3 days
How should chemical injuries be managed?
Irrigate immediately with at least 2L of water and evert eyelids
Check pH after irrigation and then at 5 and 20 mins
What is the difference between acidic and alkaline chemical injuries?
Acidic (e.g. sulfuric acid) - coagulative necrosis
Alkaline (e.g. lime) - worse than acid, causes liquefactive necrosis which can penetrate further
What signs may be seen on anterior segment blunt trauma?
Cornea - abrasion, oedema
Hyphaema (blood)
Iris - miosis or mydriasis, sphincter rupture
Lens - cataract, subluxation
What signs may be seen on posterior segment blunt trauma?
Vitreous - detachment, haemorrhage
Retina - bruising, bleeding, tears, detachment
Choroid - rupture
Optic nerve - traumatic neuropathy
What are the symptoms of globe rupture?
Extreme pain Obvious penetrating trauma or suspicious mechanism of injury Irregular pupil 360 degree subconjunctival haemorrhage Flat anterior compartment
How is suspected globe rupture managed?
Do not press on the globe Measure visual acuity Slit lamp and pupils if able CT (thin slice) Refer to ophthalmology
How should lid lacerations be assessed?
Clean
Assess for associated injuries
Check if - full thickness, involves lid margin, puncta involvement
Suture
How does retrobulbar haemorrhage present?
Reduced vision RAPD Raised pressure Pain Proptosis Reduced motility
What type of orbital fracture is most common and how is it managed?
Floor
Most suitable for OP review
What are the symptoms of orbital cellulitis and how does this differ from preseptal?
Proptosis Painful/restricted movemement Reduced visual acuity Reduced colour vision RAPD (None of these features occur in preseptal)
How is orbital cellulitis managed?
Ophthalmic emergency
IV antibiotics
CT
What bacteria are commonly implicated in orbital cellulitis?
Strep pneumoniae
Staph aureus
Strep pyogenes
Haemophilus influenzae
What is Hutchinson’s sign?
Relates to involvement of the tip of the nose from facial herpes zoster
It implies involvement of the external nasal branch of the nasociliary nerve (branch of the ophthalmic division of the trigeminal nerve) and thus raises the spectre of involvement of the eye
What is amblyopia?
A reduction in visual acuity due to a problem with focusing in early childhood
What causes amblyopia?
Stabismus (lazy eye)
Refractive defects
Congenital cataracts
What is strabismus?
A condition in which the eyes do not properly align with each other when looking at an object
AKA lazy eye/squint
How is amblyopia diagnosed?
Visual acuity
Eye movements
How is strabismus managed?
Eye patches or drops (atropine) to obscure the good eye and force the brain to process information from the affected eye for 4-6 hours/day
How is amblyopia caused by refractive error managed?
Glasses
Give 3 differentials of dry eye
Allergy Conjunctivitis Glaucoma HSV VZV Thyroid disease Sjogren's syndrome
Give 3 causes of dry eyes
Elderly - reduced tear secretion Contact lenses Staring at screens - reduced blinking Diabetes Cataract surgery
How do dry eyes present?
Watery eyes Dry, gritty sensation Worse towards end of day Eyelids may be red and sticky Usually bilateral
What are the red flags for dry eyes?
Eye pain Altered visual acuity Photophobia Significant redness Diplopia Acute onset
What investigation can be done for dry eyes?
Schirmer’s test - strip of filter paper in fornix to measure advancing edge of tears
How are dry eyes managed?
Artificial tears/ointment 3-4 times/day Acetylcysteine drops (disperse mucus) Medication review Smoking cessation Minimise contact lens wear Blink more frequently, break from screens Temporary punctal plug
What are the complications of dry eyes?
Conjunctivitis
Keratitis
Ulceration
Infection
What is blepharitis?
A condition where the edges of the eyelids become red and swollen
What is a chalazion, how does it present and how is it managed?
Granuloma of meibomian glands
Hard, inflamed lump visible on lid eversion
Warm compress, chloramphenicol, incise
What is a stye, how does it present and how is it managed?
Infection of the lash follicle
Red, tender swelling of lid margin which may have a head of pus
Warm compress and chloramphenicol
What is a marginal cyst, how does it present and how is it managed?
Cysts of sweat (Moll) or lipid (Zeiss) glands
Dome shaped, no inflammation
Removal for cosmetic reasons only
What is the most common eyelid malignancy, how does it present and how is it managed?
Basal cell carcinoma
Mainly lower lid, does not metastasise, local infiltration
Pearly smooth edge with necrotic core or diffuse indurated lesion
Excision or radiotherapy
How does blepharitis present and how is it managed?
Inflamed lid margin, blocked meibomian glands, margin crusting
Keep lids clean, treat infection, artificial tears
What eye movement/s are controlled by the superior rectus muscles?
Abduction
Elevation
What eye movement/s are controlled by the lateral rectus muscles?
Abduction
What eye movement/s are controlled by the inferior rectus muscles?
Abduction and depression
What eye movement/s are controlled by the inferior oblique muscles?
Adduction
Elevation
What eye movement/s are controlled by the medial rectus muscles?
Adduction
What eye movement/s are controlled by the superior oblique muscles?
Adduction
Depression
How do you describe a squint?
Persistence - manifest squint (present all the time), latent squint (present on dissociation)
Direction of deviation - exotropia (divergent), esotropia (inwards), hypertropia (upwards), hypotropia (downwards)
Give 3 causes of a squint?
Blowout fracture Diabetes Hypertension Aneurysm (posterior communicating artery) Cavernous sinus thrombosis Acoustic neuroma Glioma Sarcoidosis Vasculitis Raised ICP Cataracts Retinoblastoma High refractive error
What is ischaemic optic neuropathy and what are the 2 different types?
Damage of the optic nerve caused by a blockage of its blood supply
Arteritic (e.g. GCA) and non-arteritic
What are the symptoms of giant cell arteritis?
Headache Jaw claudication Malaise Myalgia Depression
How is GCA diagnosed?
Clinical features and suspicion
Elevated ESR and CRP
Temporal artery biopsy
How is GCA managed?
High dose systemic steroids - 1-2 mg/kg/day with daily ESR monitoring
Prophylaxis - bisphosphonate, PPI
What is Charles Bonnet syndrome?
A disease in which visual hallucinations occur as a result of vision loss
What are the symptoms of Charles Bonnet syndrome?
Hallucinations - simple (lines, light flashes) or complex (people, animals), not disturbing, patient aware they are not real, often on wakening, last several minutes
How is Charles Bonnet syndrome managed?
Optimal eye care Low vision aids Avoidance of - stress, anxiety, social isolation, sensory deprivation Reassurance Medication - olanzapine, clonazepam Rapid eye movements/blinking Repetitive TMS
What is endophthalmitis?
Inflammation of the interior cavity of the eye, usually caused by infection. It is a possible complication of all intraocular surgeries, particularly cataract surgery, and can result in loss of vision or loss of the eye itself.
What organisms can cause endophthalmitis?
Staphylococcus
Streptococcus
Gram negatives
Fungi
What are the risk factors for endophthalmitis?
Surgical - increased operative time, posterior capsule rupture, wound leakage
Contamination - patient’s bacterial flora, instruments, corneal transplant donor
Patient - diabetes, immunosuppression, HIV
What are the symptoms of endophthalmitis?
Visual loss
Pain
Redness
Photophobia
What are the signs of endophthalmitis?
Lid oedema Conjunctival chemosis and hyperaemia Corneal haze Cells and flare in anterior compartment (exudate/hypopyon) Absent/sluggish pupillary light reflex Absent red reflex
What are the differentials for endophthalmitis?
Post-operative inflammation without infection
Acute red eye - anterior uveitis
Vitreous haemorrhage
How is endophthalmitis managed?
Anterior chamber/vitreous tap or vitrectomy followed by microbiology of specimen
Antibiotics
Steroids
What is retinoblastoma?
Most common intraocular malignancy in children
How does retinoblastoma present?
Age <3 years Leukocoria (white pupillary reflex) Strabismus Pseudo-orbital cellulitis Visual disturbance Ocular pain
What are the risk factors for retinoblastoma?
RB1 gene mutation
HPV exposure
Advanced parental age
Family history
How is retinoblastoma investigated?
Examination under anaesthesia USS MRI LP Bone marrow aspirate Bone scan Genetic testing
How is retinoblastoma managed?
Small - cryotherapy, laser therapy, radioactive plaque, thermotherapy
Large - chemotherapy, enucleation (removal of eye), radiotherapy
How might the normal function of the eye be affected by drugs used in ITU?
Muscle relaxants - reduce tonic contraction of orbicularis muscle which normally keeps lids closed
Sedation - reduced blink rate and reflex
What type of ITU patients are at higher risk of eye damage?
Mechanically ventilated
Greater length of stay
Use of sedatives/paralytics
Those on positive pressure ventilaton
What conditions can affect the eye in ITU?
Corneal abrasion Exposure keratopathy Chemosis Conjunctivitis Keratitis
What is lagophthalmos?
Incomplete closure of the eyelid
What measures can be taken to protect the eyes in ITU?
Manual closure/taping of eyes shut
Lubricating ointment
How is exposure of the eyes graded in ITU?
Grade 0 - no exposure
Grade 1 - any conjunctival exposure
Grade 2 - any corneal exposure
Give 4 complications of contact lens wear
Microbial keratitis Allergies Papillary conjunctivitis Corneal abrasion CL induced acute red eye (CLARE) Corneal infiltrates Dry eyes Neovascularisation
What can be used to predict diabetic eye disease?
Measures of renal microvasculature damage - proteinuria, blood urea nitrogen, creatinine
What is the most accurate predictor of diabetic retinopathy? What are the additional risk factors?
Duration of diabetes
Smoking, hypertension, pregnancy
What are the 2 different types of diabetic retinopathy and which is most common?
Non-proliferative (most common, 95%)
Proliferative
What features of non-proliferative diabetic retinopathy may be seen on fundus exam?
Vessel microaneurysms Dot and blot haemorrhages Flame haemorrhages Cotton wool spots Beading of retinal veins
What is the defining feature of proliferative diabetic retinopathy seen on fundus exam?
Neovascularisation
What are the complications of neovascularisation in proliferative diabetic retinopathy?
Blindness
Detachment
Haemorrhage
What is the most common cause of blindness in diabetic patients and how does this occur?
Macular oedema
Leakage of capillaries and aneurysms at the macular retina which causes fluid swelling
What features of macular oedema can be seen on fundus exam?
Macula appears cloudy and elevated
Hard yellow exudates
How is diabetic retinopathy managed?
Tight diabetic control
Surgical treatment - laser or vitrectomy
How is macular oedema treated with laser?
Laser seals off leaking vessels and microaneurysms by burning them - selective for small areas or grid photocoagulation for larger areas
How are advanced retinopathy and neovascularisation treated with laser?
Pan-retinal photocoagulation (PRP) - thousands of spots are burned around the peripheral retina to destroy the ischaemic part and reduce angiogenic signals
What are the complications of PRP?
Peripheral vision loss
Decreased night vision
How is a vitrectomy carried out?
Removal of vitreous humour from the eye and replacement with saline - removes haemorrhaged blood, inflammatory cells and other debris