Ophthalmology Flashcards
Define Acute closured angle glaucoma
A type of glaucoma characterised by the blockage or narrowing of the drainage angle formed by the cornea and the iris, resulting in a sudden increase intraocular pressure - primary ACAG = when the iris blocks the channel
Acute closure glaucoma risk factors
Hyperopia, age (lens grows w/ age and can push iris), Asian or Inuit ethnicity, pupillary dilatation (iatrogenic or due to being in a dark room)
Acute closure glaucoma features
- Sudden onset, acutely painful eye
- Blurred vision
- Haloes around lights
- N&V
- Red eye = ciliary flush w/ a hazy cornea
- Mid-dilated or fixed pupil
- Closed iridocorneal angle on gonioscopy
- Corneal oedema
- Raised intraocular pressure (>21) - globe may feel hard on palpation
Acute closure glaucoma investigations
- Gonioscopy to asses angle between iris and cornea
- Tonometry = measures IOP
- Examination of eye
Acute closure glaucoma management
IOP must be reduced ASAP to prevent further dmg to the ocular nerve and preserve vision:
- IOP-lowering agents = beta blockers, pilocarpine and IV acetazolamide
- IV mannitol if those don’t work (rare)
- Analgesia and antiemetics
Aim of medical management is to stabilise/reduce IOP whilst awaiting definitive surgical intervention:
- Peripheral iridotomy = laser used to make a hole in the peripheral iris to allow free flow of aqueous (contralateral eye also treated prophylactically)
- Surgical iridectomy = rarely used
Define Age-related macular degeneration
The degeneration of photoreceptors in the central retina (macula) that leads to the formation of drusen, which are visible on split-lamp biomicroscopy - can be dry or wet
Dry VS wet macular degeneration
Dry:
- 85-90% of cases
- Has drusen (yellow pigmented spots on retina) and macular thinning
- Slowly progresses over decades
Wet:
- 10-15% of cases
- Has neovascularisation, bleeding and leakage of fluid
- Rapidly progresses over months w/ poor prognosis
Age-related macular degeneration features
- Progressive loss of vision (worse for near and central vision)
- Variablitiy in visual disturbance from day to day
- Poor night vision
- Photopsia = perceived flickering of lights
- Glare
- Visual distortion (esp line perception = metamorphopsia)
Age-related macular degeneration investigations
- Slit-lamp biomicroscopy = allows identification of drusen or haemorrhages for diagnosis
- Colour fundus photography = done at each assessment to monitor progression
- Fluorescein angiography = used to identify neovascular ARMD to guide anti-VEGF therapy
- Ocular coherence tomography = allows assessment of all layers of the retina and identification of disease not visible of split-lamp
Age-related macular degeneration management
- Smocking cessation
- Dry = zinc, antioxidants, Vit A/C/E have been shown to reduce progression
- Wet = anti-VEGF injections to limit progression and even reduce vision loss (done monthly)
Define Amblyopia
AKA lazy eye - A developmental defect of cortical visual processing resulting from abnormal visual stimulation during early childhood, which leads to visual impairment - usually unilateral but can affect both eyes
Amblyopia causes
Any cause of reduced visual stimulation on 1 eye:
- Squints
- Unequal refractive error
- Congenital cataracts
- Tumours blocking the visual axis
Amblyopia features
- Blurred or cloudy vision
- Double vision
- Poor depth perception
- Eye fatigue
- Strabismus
Amblyopia management
Patch the good eye before the age of 8
Define Bacterial keratitis
A bacterial infection of the cornea, a common but sight-threatening ophthalmic emergency - often associated with minor trauma to the cornea, contact lens use or ocular surgery - most common bacteria in contact lens users = Pseudomonas
Bacterial keratitis features
- Pain
- Foreign body sensation
- Tearing/purulent discharge
- Red eye
- Corneal ulcers - may be visible w/ fluorescein staining
Bacterial keratitis investigation
- Emergency evaluation by ophthalmologist
- Corneal scrape to identify organisms = diagnostic
- Send contact lenses for culture
- Slit-lamp to assess cornea
Bacterial keratitis management
- Cessation of contact usage
- Topical (or sometimes oral) quinolones
- Cyclopentolate can be used for pain relief
Differentials for a tumour of the eyelid
- BCC = pearly sheen, rolled edges, ulcerative
- Squamous papilloma = papillary shaped w/ keratinised surface
- Seborrheic keratosis
- Sty
- Chalazion = initially painful but resolves to leave a non-tender lump
- Naevus = well-demarcated, pigmented lesion
- Xanthelasma = soft yellow lesion
- Molluscum contagiosum
- Hidrocystoma/cystadenoma = cystic lesions occurring due to blocked sweat glands
- Epidermoid cyst = inflamed/infected hair follicle
- Dacryocystitis = cystic lesion caused by blockage of the nasolacrimal gland
Define Blepharitis
A term that encompasses various conditions which cause chronic inflammation of he eyelid margin
Blepharitis causes
Staph infections, HSV or VZV infections, Meibomian gland dysfunction, seborrheic dermatitis or rosacea
Blepharitis features
Symptoms:
- Painful, gritty, itchy eyes
- Eyelids sticking together upon waking
- Dry eyes
- Symptoms associated w/ causative condition
Signs:
- Erythema of the eyelid margin
- Crusting or scaling at eyelid margin
- Visibly blocked Meibomian glands
Blepharitis management
Is a chronic condition w/ no cure - can be controlled:
- Lid hygiene at least twice a day
- Avoid contact usage during flare ups
Define Carotid cavernous fistula
An abnormal communication between the carotid artery and the cavernous sinus, leading to bleeding into the sinus - can be idiopathic or due to trauma (head injury, surgery, sinus thrombosis, aneurysm)
Carotid cavernous fistula features
- Pulsatile proptosis = forwards displacement of the eye associated w/ a pulsating sensation
- A bruit
- Severely injected conjunctiva
- CN III, IV and V impingements
Carotid cavernous fistula investigations
- Angiography (gold standard)
- MR/CT
Carotid cavernous fistula management
- Endovascular techniques = coil embolization or balloon occlusions
- Surgical repair if that doesn’t work
- Corticosteroids
Define Cataract
An opacity in the lens, typically caused by the denaturing of lens proteins
Cataract features
- Gradual painless loss of vision
- Haloes around lights, particularly at night
- Loss of red reflex
- Brown/white appearance of the lens upon slit-lamp biomicroscopy
Cataract management
Surgical intervention:
- Phacoemulsification = braking down the existing lens w/ US waves
- The a Psuedophakia = implanting an artificial lens
Cataract surgery complications
- Endophthalmitis = severe pain, loss of vision, hyperaemia - occurs w/in days
- Posterior lens capsule opacification = blurry vision and a visible white opacity - occurs w/in a few weeks
What is the blood supply of the retina?
1) Central retinal artery:
- A branch of the ophthalmic artery, which itself is the 1st branch of the carotid artery
- Enters the eye at the optic disk, then branches into the superior and inferior retinal arteries, before branching again into the temporal and nasal subdivisions, which each supply a quadrant
2) Choriocapillaries = capillaries of the choroid which supply the peripheral retina
Define Central retinal artery occlusion
Occlusion of the central retinal artery (essentially a stroke of the eye) before it branches into the superior and inferior retinal arteries - occlusions after the branching = branch retinal artery occlusion
Central retinal artery occlusion causes
- Atherosclerosis (90%)
- Embolism
- Inflammatory (GCA, SLE)
- Thrombophilia
Central retinal artery occlusion features
- Sudden-onset, painless loss of vision that typically occurs over seconds - in almost all cases vision is reduced to counting fingers
- Pts may report a Hx of amaurosis fugax
- Classical finding is a pale retina w/ a cherry red spot at the macula - on fundoscopy
- Pts may have a RAPD
Central/branching retinal artery occlusion management
Dmg becomes irreversible very quickly, so treatment beyond 90-100 minutes is unlikely to improve vision
Aim of treatment is to reperfuse the ischaemic retina:
- Ocular massage aiming to dislodge the embolus
- Vasodilation w/ isosorbide dinitrate
- Anterior chamber paracentesis aiming to reduce the IOP to help dislodge to embolus
Long-term management = secondary prevention of further ischaemic incidents
Branching retinal artery occlusion features
Sudden-onset, painless loss of the visual fields supplies by the occluded artery
Central retinal vein occlusion features
- Sudden, painless loss of vision or visual field defects
- Retinal neovascularisation and subsequent haemorrhage
Central retinal vein occlusion fundoscopy findings
Findings described as a “stormy sunset”:
- Numerous flame haemorrhages
- Dot and blot haemorrhages
- Cotton wool spots
- Retinal oedema
- Dilated or tortuous retinal veins
- Visual field defects, depending on the site of the occlusion
Central retinal vein occlusion management
- Retinal neovascularisation is managed w/ laser photocoagulation
- Macular oedema is treated w/ intravitreal anti-VEGF or corticosteroids if those are contraindicated
Define Chronic open angle glaucoma
The death of optic nerve fibres w/ or w/out raised IOP - this is due to progressively impaired aqueous humour drainage through the trabecular meshwork causing IOP - the pressure gradual dmgs the optic nerve
Chronic open angle glaucoma risk facors
- Raised IOP
- HTN
- DM
- Corticosteroids
- Myopia
- Afro-Caribbean
- Increased age
- Genetics
Chronic open angle glaucoma features
Pts typically have no symptoms and the glaucoma is diagnosed through screening tests
Advanced cases show loss of peripheral vision and central scotoma (blind spot)
Fundoscopy/slit-lamp assessment may show:
- Pale optic disc = indicates nerve atrophy
- Optic disc cupping = cup:disc >0.7
- Retinal vessel bayonetting = when vessels appear to have a break as they enter the deep cup and then reappear at the base
Chronic open angle glaucoma investigations
- IOP measurements w/ Goldmann applanation tonometry (gold standard)
- Central corneal thickness measurements - variations is thickness can affected the IOP measurements
- Automated visual field measurements
Chronic open angle glaucoma management
Primary goal is to prevent disease progression and preserve visual fields and acuity - difficult to reverse dmg done.
Primarily done by reducing IOP - treatment is indicated if IOP >24 mmHg or there is an identifiable risk of visual impairment
1st line = surgical management w/ selective laser trabeculoplasty
2nd line = medical - prostaglandin analogues (latanoprost) then beta blockers (timolol)
Types of Conjunctivitis
Allergic (most common) = type I hypersensitivity reaction commonly to pollen, dust mites or pet dander
Viral (most common infective) = most often caused by adenoviruses but can also be due to HSV - often associated w/ URTIs and colds
Bacterial = commonly due to staph aureus, strep pneumoniae, haemophilus influenzae and Moraxella catarrhalis - can also be due to gonorrhoea and chlamydia
Conjunctivitis features
- Eye redness
- Itching
- Irritation
- Excessive tearing
- Discharge = serous in allergic and viral, purulent in bacterial
- Photophobia suggests corneal involvement= keratoconjunctivitis
Conjunctivitis management
- Allergic = antihistamines
- Viral = self-limiting
- Bacterial = self-limiting, but can use chloramphenicol if severe
Define Corneal arcus
The deposition of lipids in the periphery of the cornea, resulting in visible white/blue/grey opaque rings - common in the elderly, but in under 40’s it may be indicative of underlying lipid metabolism disorder
Corneal graft rejection features
- Oedema
- Iritis
- Redness
- Pain
- Visual loss
Corneal graft rejection management
- Intensive topical steroid treatment to supress immune response
- Frequent follow-ups
- Re-grafting if severe
Define Dacryocystitis
An infection of the lacrimal sac, typically resulting from an obstruction in the nasolacrimal (tear) ducts as the stagnant fluid breeds bacteria
Dacryocystitis features
- Pain and tenderness of the medial canthus
- Watering of the eye
- Potential presence of purulent discharge
Dacryocystitis management
- Systemic abx
- Analgesia
- Close monitoring to prevent the spread to the conjunctiva or orbit
Stages of Diabetic retinopathy
Non-proliferative diabetic retinopathy:
- Mild NPDR = microaneurysms and dot haemorrhages on fundoscopy
- Moderate NPDR = microaneurysms, dot and blot haemorrhages, cotton-wool spots and hard exudates
- Severe = beaded veins, intra-retinal microvascular abnormalities and extensive retinal haemorrhages
Proliferative diabetic retinopathy = neovascularisation and fibrous proliferation on the retina or vitreous (higher risk of severe vision loss)
Diabetic retinopathy pathophysiology
Chronic hyperglycaemia leads to thickening of the BM and loss pericytes in the retinal capillaries.
This results in capillary occlusion and leakage, leading to retinal ischaemia and formation of new, fragile vessels
Diabetic retinopathy features
- Early stage = asymptomatic
- Floater or dark spots in the vision
- Blurred or distorted vision
- Loss of night vision
- Sudden loss of vision
- Fundoscopy changes
Diabetic retinopathy management
- Optimisation of glucose control
- Laser photocoagulation for PDR and clinically significant macular oedema
- Intravitreal injections of anti-VEGF agents for macular oedema
- Vitrectomy surgery for advanced cases e.g. vitreous haemorrhage or retinal detachment
Diabetic retinopathy complications
- Vitreous haemorrhage
- Tractional retinal detachment
- Macular oedema
- Neovascular glaucoma
- Blindness
Define Subconjunctival haemorrhage
Harmless haemorrhage into the space between the conjunctiva and the sclera due to rupture of a fragile blood vessel - commonly caused by coughing, sneezing or eye trauma (always check for Warfarin and BP)
Subconjunctival haemorrhage features
Completely bloodshot/blood filled eye
Define Endophthalmitis
Severe inflammation of the interior of the eye, commonly resulting from infection - primarily occurs post-surgery (e.g. cataracts) but rarely from endogenous seeding
Endophthalmitis features
- Red eye
- Eye pain
- Decreased visual acuity
- Photophobia
- Floaters
- Hypopyon (pus collection in the anterior chamber)
Endophthalmitis investigations
Detailed ocular exam
Microbial culture of vitreous and aqueous humour
Endophthalmitis management
Intravitreal antibiotics (usually vancomycin)
In severe cases, vitrectomy may be required
What is the Sclera?
The white, fibrous tissue that covers the outside of the eyeball
What is the Epiclera?
A thin, clear vascular membrane that covers the sclera
Located between the sclera and conjunctiva
What is the Conjunctiva?
A thin, clear membrane that covers the inner surface of the eyelid and outer part of the eye (above the sclera and episclera)
Scleritis features
- Red eye/visible vessels
- Severe pain in the orbit and on eye movements
- Bluish tinge to the whites of the ey (in severe/necrotising disease)
- Systemic symptoms in 50% of pts
Episceritis features
- Tenderness over the inflamed area
- Milder/no pain compared to scleritis
- Visible vessels which move/blanch when pressed w/ a cotton wool bud
Scleritis management
- NSAIDs e.g. flurbiprofen
- Corticosteroids for more severe cases
- Steroid-sparing agents for long term
Episceritis management
Supportive e.g. artificial tears - most cases resolve w/in weeks
Define Herpes simplex keratitis
Severe infection by reactivated HSV1 - primarily affects the cornea
Herpes simplex keratitis features
- Acute pain
- Photophobia
- Epiphora (excessive tearing)
- Pathognomonic dendritic ulcers under slit-lamp w/ fluorescein
Herpes simplex keratitis management
- Topical acyclovir
- Phylactic antivirals in recurrent cases
- Corneal transplant in severe cases
Define Herpes zoster ophthalmicus
Infection of the ophthalmic division of the trigeminal nerve by VZV that lay dormant in the trigeminal ganglion - can also invade the cornea
Herpes zoster ophthalmicus features
- Painful red eye
- Fever
- Malaise
- Headache
- Erythematous vesicular rash over the trigeminal division of the ophthalmic nerve
Hutchinson’s sign = a skin lesion on the tip or side of the nose, indicative of nasociliary nerve involvement - this indicates a higher risk of ocular involvement, so pts w/ this sign should have an urgent ophthalmology review
Herpes zoster ophthalmicus management
Pts w/ Hutchinson’s sign should be urgently reviewed
Oral acyclovir +/- topical steroids
Hypertensive retinopathy pathophysiology
Caused by prolonged HTN leading to dmg to the retinal vasculature - this is due to changes in the arteriole structure leading to vasoconstriction and leakage
Hypertensive retinopathy features
- Asymptomatic in early stages
- Blurred vision
- Sudden vision loss
- Floaters
- Fundoscopy changes
Grades of Hypertensive retinopathy
- Grade I = Vascular attenuation (narrowing of the retinal arteries)
- Grade II = Above + AV nipping
- Grade III = Above + retinal haemorrhages, hard exudates and cotton wool spots
- Grade IV = Above + optic nerve oedema + silver wiring (increased arteriole light reflex due to sclerosis)
Hypertensive retinopathy management
- Control HTN
- Laser photocoagulation for neovascularisation or macular oedema
- Anti-VEGF for neovascularisation
Intra-ocular foreign body investigations
Pts suspected of having an IOFB should have an urgent CT scan for confirmation
Intra-ocular foreign body management
- Urgent surgical intervention
- Abx + steroid eye drops post-operatively
Define Ischaemic optic neuropathy
A broad term which describes optic nerve dmg due to a lack of blood supply - categorised into anterior (most common) and posterior ION
Define Arteritic Ischaemic optic neuropathy
An anterior ION that is due to inflammation of blood vessels supplying the optic nerve - almost always due to GCA and is an ophthalmic emergency
Define Non-arteritic Ischaemic optic neuropathy
An anterior ION that is due to insufficiency in the blood vessels supplying the retina as a result of CV risk factors (e.g. atherosclerosis, DM, HTN)
Ischaemic optic neuropathy features
Arteritic:
- GCA symptoms
- Sudden loss of vision
- Amaurosis fugax
- Altitudinal visual field defects
- Swollen optic disc
- RAPD
Non-arteritic:
- Sudden loss of vision (can be progressive)
- Usually painless but rarely can be painful
- RAPD
- Loss of visual fields
- Swollen optic disc
Ischaemic optic neuropathy management
Arteritic = immediate systemic corticosteroids
Non-arteritic = no proven treatment, manage RFs
Define Kayser-Fleischer rings
Copper coloured rings around the periphery of the cornea - associated w/ Wilson’s disease, cholestasis and PBC
Define Keratoacanthoma
A rapidly growing skin lesion which develops from a hair follicle in sun exposed skin - looks like an SCC, but not invasive or metastatic - typically is a enlarged dome-shaped nodule w/ a central keratin-filled crater or horn - managed w/ excision
Define Light near dissociation
A clinical sign where the pupil constricts on convergence or focusing on a near object, but does not constrict in response to direct light exposure
Causes of a Light near dissociation
- Meningitis
- Alcoholism
- Argyll-Robinson pupil
- Adie syndrome
- Pinealoma (tumour of the pineal gland which produces melanin)
Primary ocular tumours
- Retinoblastoma = most common ocular malignancy in children
- Ocular melanoma = most common ocular malignancy in adults - usually arising in the uvea (choroid, ciliary body or iris)
- Intraocular lymphoma = often affecting the retina or vitreous
- Conjunctival melanoma
- Eyelid carcinoma
- Lacrimal gland tumours
Cancers which can metastasise to the eye
- Breast cancer = most common cause in women - affects the choroid
- Lung caner = most common cause in men
- Kidneys
- Thyroid
- Prostate
Define Onchocerciasis
AKA river blindness - a progressive, chronic disease of the skin and eyes caused by the parasite Onchocerca volvulus (prevalent in rivers in the intertropical zone of Latin America and Arab penisula) - it is transmitted to humans by Blackfly bites
Onchocerciasis features
Ocular:
- Itchy eyes
- Ocular pain
- Photophobia
- Blurred vision
- Glaucoma
- Night blindness
- Progressive blindness
Skin:
- Diverse patters of presentations e.g. rashes, nodules
- Pts can have multiple skin manifestations
Onchocerciasis management
Oral ivermectin
Define Ophthalmia neonatorum
AKA neonatal conjunctivitis = conjunctivitis w/in the first 28 days of life - commonly caused by gonococcal or chlamydia infection
Ophthalmia neonatorum management
Topical or IV erythromycin (depending on severity) - prompt treatment is required to avoid blindness
What does optic disc pallor represent?
A characteristic sign of optic atrophy where there is loss of optic nerve fibres - the end stage for many diseases
Optic disc pallor clinical manifestations
- Decreased visual acuity
- Changes in the field of vision
- Changes in colour vision
- Loss of peripheral vision
- Photopsia
Causes of optic disc pallor
- Glaucoma
- Retinitis pigmentosa
- Choroiditis
- CRAO
- MS
- Leber’s optic atrophy
- Syphilis
- Persistent papilledema
Papilledema causes
Unilateral:
- Vascular = DM, CRAO
- Inflammatory = uveitis, sarcoidosis
- Infective = herpes, toxoplasmosis, viral
- Optic neuritis (MS)
- Lymphoma
Bilateral:
- Raised ICP
- Malignant HTN
- DM
- Toxicity
- Ethambutol
- Lymphoma
Papilledema features
Symptoms:
- Headache worse on standing
- Increased hypermetropia (due to eye shape changes)
- Transient vision loss (esp when standing)
Signs:
- Blurring of optic disc margin
- Absent venous pulsations of fundoscopy
- Haemorrhage over or near optic disc
- Increased size of blind spot
Papilledema investigations
All Pts should be suspected of having an intracranial mass until proven otherwise
Use the Frisen scale for classification of severity:
- Stage 0 = normal
- Stage 1 = very early
- Stage 2 = early
- Stage 3 = moderate
- Stage 4 = marked
- Stage 5 = severe
Define Orbital cellulits
Infection of the structures behind the orbital septum (a membranous sheet extending from the superior/inferior orbital rims and into the eyelid)
Define Preseptal cellulits
Infection of tissue anterior to the orbital septum
Orbital/preseptal cellulits risk facotors
Trauma, surgury, sinus infections (esp erthmoid), preseptal infections, dental abscesses, dacryocystitis
Orbital cellulits features
- Periocular pain and swelling
- Fever
- Malaise
- Erythematous, swollen and tender eyelid
- Chemosis (conjuctival swelling)
- Proptosis
- Restricted eye movements +/- diplopia
Preseptal cellulitis features
- Erythematous swollen eyelid
- Mild fever
- Erythema surrounding the orbit
- Normal eye movements, optic nerve function
- No proptosis or chemosis
Orbital/preseptal cellulits investigations
CT orbit to distringuish between them
Orbital cellulits management
IV abx
Preseptal cellulits management
Young/systemically unwell = admit for IV abx
Else, oral abx and daily ophthalmological review
Define Orbital blowout fracture
An orbital fracture where the orbital wall is fractured due to a sudden increase in intraocular pressure from the impact - most commonly affects the orbital floor and medial orbital walls as these are the weakest points
Orbital blowout fracture features
- Pain, particularly on eye movements
- Swelling/bruising around the eye
- Visual disturbances
- Decreased eye movement
- Numbness in the distribution of the infraorbital nerve
- Vertical diplopa and restircted upgaze = can occur if the inferior rectus muscle becomes entrapped
Define Posterior vitreous detachment
Where the vitreous gel (clear substances that fills the space between the lens and the retina) seperates from the retina
Posterior vitreous detachment causes
- Aging = vitreous gel shrinks and can naturaly sperate
- Eye trauma
- Severe myopia
Posterior vitreous detachment features
- Photopsia = sudden flashes of light perceived by the pt
- Floaters = spots or cobwebs in the vision
Posterior vitreous detachment investigations
Fundoscopy
Posterior vitreous detachment management
Regular fundoscopy to monitor for complications (e.g. retinal tears/detachment) - concidered a normal part of aging
Define Pterygium
Pathological overgrowth of the conjuctiva onto the corneal surface - tends to occur in people who have spent a lot of time outside as UV may be a risk factor
Pterygium features
- Reduced visual acuity
- Eye irritation
- Presence of a visible white fibrous opacity over the cornea, continuous w/ the conjuctiva
Pterygium management
- Artifical tears
- Corticosteroid eye drops (if needed to reduce inflammation)
- Surgical resection (if causing severe visual impairment)
Define Retinal detachment
Seperation of the retina from the retinal pigment epithelium
Retinal detachment causes
- Trauma
- Severe myopia (can thin the retina)
- Previous eye surgery (esp cataracts)
- DM
- SCA
- Age-related changes to the vitreous
Retinal detachment features
- Floaters
- Photpsia (flashes of light)
- Progressive and rapidly reducing visual acuity and visual field loss
- Painless
The danger is that if the detachment reaches the macula sight may be perminantly lost
Retinal detachment investigations
- Fundoscopy = ensure to check if the macula is on or off as this informs management
- Eye US
- Optical coherence tomography = to provide corss-sectional images of the retina
Retinal detachment management
- Laser or cryotherapy = to seal retinal tears of holes
- Vitrectomy = remove the vitreous and replace w/ a gas bubble or silicone oil
- Scleral buckling = to push the sclera towards the retinal tear
- Pneumatic retiopexy = push the retina back into place using a gas bubble
Define Retinitis pigmentosa
A group of inherited disoders that cause a progressive peripheral vision loss and night blindness due to the degeneration of the rod photoreceptor cells in the retina
Retinitis pigmentosa features
- Tunnel vision due to peripheral vision loss
- Night blindness
- Difficulty adapting to low light settings
- Loss of central vision in later stages
Retinitis pigmentosa investigations
- Fundoscopy = peripheral bone-spicule pigmentatation, optic disc pallor, retinal vessel attenuation
- Electroretinography = reduced or abcsent rod reponses
- Genetic testing
Retinitis pigmentosa management
- Support (e.g. visual aids)
- Vit A supplements can help slow degredation in some pts
Retinoblastoma aetiology
Can be herditary (germline mutation in RB1 gene) or non-hereditary (somatic mutation in RB1 gene)
Retinoblastoma features
- Primary symptom = leukocoria (white pupil)
- Deteriorating vision
- Strabismus
- Failure to thrive
Retinoblastoma managment
Radiotherapy or Enucleation +/- chemo
Define External hordeolum
AKA Stye = An abcess at an eyelash follicle, typically caused by staph
Define Internal hordeolum
An abcess of the Meibomian glands - can lead to a chalazion if it becomes blocked
Define Chalazion
A blocked Meobiam gland (often by an abcess)
Chalazion features
Initially painful eyelid, then evolves into a non-tender swelling which typically points outwards (laterally)
Stye features
Painful, red, hot lump on the eyelid which typically points inwards (medially)
Chalazion/Stye management
- Warm compresses several times a day to promote drainage
- Analgesia
- Topical abx
- If persisten, surgical drainage
Thyroid eye disease features
- Swelling of the orbital fat and extraocular muscles - results in bulging eyes
- Ocular pain, worse on movement
- Painful eyelids
- Dry, red eyes
- Lid retraction and lid lag
- Proptosis/exophthalmos
- Chemosis
- Orbital fat prolapse
- Exposure keratosis = corneal dmg and infection due to pt not being able to close their eyes
- Diplopia from ocular muscle fibrosis
- Compressive optic neuropathy resulting in progressive visual loss
Thyroid eye disease management
- Thyroid control
- Steroids/immunosupression
- Orbital decompression surgery followed by IV steroids for sight-threatening disease
- Conservative management of symptoms
Define Trachoma
Keratoconjuctivitis (inflammation of the cornea and conjuctiva) due to infection by Chlamydia
Trachoma managament
Single dose of oral azithromycin
Define Anterior uveitis
Inflammation of the iris or ciliary body at the front of the eye
Define Intermidiate uveitis
Inflammation of the vitreous and peripheral retina
Define Posterior uveitis
Inflammation of the retina and choriod
Define Panuveitis
A rare condition where there is inflammation throughout the whole uveal tract - the iris, ciliary body, choroid, retina and vitreous
Anterior uveitis causes
AI:
- SLE
- Ankylosing spondylitis
- Behcets disease
- Juvinile idiopathic arthritis
- MS
- IBD
- Granulomatosis w/ polyangiitis
- Reactive arthritis
Other:
- Trauma
- Infections (herpes, TB, HIV, syphilis)
- Iatrogenic
- Ischaemia
Anterior uveitis features
Symptoms:
- Painful red eye worsening over several days
- Photophobia
- Blurred vision
- Headache
Signs:
- Conjuctival injections
- Hypopyon (when white blood cells accumulate in the anterior chamber of the eye, forming a whitish layer of fluid)
- Keratic precipitates
- Irregular pupil due to ciliary body contractions
- Anterior chamber flare/cells
Intermediate uveitis features
Symptoms:
- Often painless
- Floaters
- Blurred vision
Signs:
- Inflammatory cells w/in the vitreous
Posterior uveitis features
Symptoms:
- Progressive vision loss
- Floaters or flashers
- Blurred vision
Signs:
-Yell/white appearance of the retina
- Cystoid macular oedema
Anterior uveitis management
Acute:
- Cycloplegic mydriatic drops (e.g. cyclopentolate) = these are anticholinergic agenets which work on the ciliary muscles to relax the pupil
- Corticosteroids
- Analgesia
Chronic = methotrexate/mycophenolate if required
Vitamin A deficiency features
Ocular (typically bilaterally):
- Night blindness
- Dryness of conjuctiva and cornea
- Keratomalacia = corneal thinning
- Bitot’s spots = irreglar foamy patches on the white of the eye due to keratin build-up
- Corneal perforation
Other:
- Dry hair and skin
- Brittle nails
- Folliculat hyperkeratosis
- Increased susceptibility to infections
Define Vitreous haemorrhage
The precense of blood w/in the vitreous humour, usually due to blood vessel rupture
Vitreous haemorrhage causes
- Proliferative diabetic retinopathy (>50% of cases)
- Retinal tear/detachement
- Trauma
- AMD
- Retinal vascular disease
Vitreous haemorrhage features
- Sudden painless loss of vision
- Blurred vision
- Floaters
- Loss of acuity
Proliferatve vitreoretinopathy = a complication of severe cases where fibrous tissue forms, increasing the risk of retinal detachment
Vitreous haemorrhage investigations
- Fundoscopy
- Slit-lamp
- Optical coherence tomography
- Fluorescein angiography
- B-scan ultrasonography = to visualise the viterous
- Orbital CT
Vitreous haemorrhage management
- Observe
- Treat underlying cause
- Viterectomy
