Opthal Flashcards
Age-Related Macular Degeneration
Degeneration of retinal photoreceptors, dry (drusen on Bruch, 90%) vs wet (worst, choroidal neovascularization)
RF - age, smoking, FHx, CVD risk factors
= bilateral, v acuity (^close up), issues at night, photopsia (flickering/ flashing), line distortion (amsler grid testing), charles-bonnet, see red patches (wet)
Inv - sit lamp, colour fundus photo baseline, optical coherence tomography, fluorescein angiography to guide wet treatment
-> anti-VEGF and photocoagulation for wet, Zinc, Vit A/C/E
ARMD: Pathophysiology
Macula: generates high-def colour vision in the central visual field, four layers
Choroid (base, contains vessels that supply the macula)
Bruch’s membrane
Retinal pigment epithelium
Photoreceptors
In wet there is new vessels formation in choroid which causes leakage of fluid, oedema and faster vision loss
In both types there are drusen (lipid and protein deposition), depletion of photoreceptors and atrophy of retinal pigment epithelium
Blepharitis
Inflammation of the eyelid margins
RF - rosacea
Cause - meibomian gland dysfunction, seborrhoeic dermatitis, staph infection
= bilateral grittiness, discomfort, sticky in mornings, red margins, swollen eyelid if staph
-> hot compress BD, remove debris, artificial tears
Comp - stye, chalazion
Diabetic Retinopathy: Features
Microaneurysm - bulges in blood vessel due to damage
Blot haemorrhage - ^vascular permeability
Hard exudates - yellow deposits of lipids and proteins due to vascular permeability
Cotton wool spots - fluffy white, retinal infarction cause damage to nerve fibres
Venous beading - walls are no longer straight/ parallel
IRMA - dilated and tortuous capillaries, act as shunt between arterial and venous vessels
Diabetic Retinopathy: Stages
Non- proliferative
Mild = microaneursysm
Moderate = MA, BH, HE and CWS and VB
Severe - BH and MA in 4 quadrants, VB in 2, IRMA in 1
Proliferative
= neovascularisation, fibrous tissue, ^T1
Maculopathy
= macular oedema, ^T2
Diabetic Retinopathy: Management
Most common cause of blindness 35-65yrs
-> optimize control, regular review, pan-retinal laser photocoagulation (SE: v field, v night), VEGF inhibitors (ranibizumab), vitreoretinal surgery
Diabetic Retinopathy: Complications
Vision loss
Retinal detachment
Vitreous haemorrhage
Rubeosis iridis (leads to neovasc glaucoma)
Optic neuropathy
Cataracts
Hypertensive Retinopathy: Features
Silver wiring - walls of arterioles thicken and sclerose, ^light reflex
AV nipping - arterioles compress the veins they cross (because of above)
Haemorrhages - dot/ blot deep in inner nuclear layer, flame in nerve fiber layer
Papilloedema - ischaemia to optic nerve so it swells, blurring of the margins
Same as diabetics - hard exudates, cotton wool spots
Hypertensive Retinopathy: Stages
Stage 1 - mild narrowing of arterioles, silver wiring
Stage 2 - AV nipping
Stage 3 - CWS, exudates, flame/ blot haem (macular star around fovea)
Stage 4 - papilloedema
Glaucoma
Damage to optic nerve 2nd to ^intra-ocular pressure
Normal IOP = 10-21
Aqueous humour produced by ciliary body
Enters anterior chamber
Leaves by canal of Schlemm in trabecular meshwork
Open-Angle Glaucoma
Gradual ^resistance to flow through trabecular mesh
RF - age, FHx, black, myopia (near), HTN, DM, steroids
= insidious, peripheral field lost (nasal scotomas to tunnel vision), v visual acuity
Inv - optic disc cupping (cup >0.6 size of disc), disc pallor, bayonetting of vessels, non-contact or applanation tonometry for IOP
-> 360° selective laser trabeculoplasty if IOP 24+, PG analogue eyedrops (lantanoprost) if not, then timolol
Angle-Closure Glaucoma
Iris bulges forwards and seals off tm, ^pressure in ant. and post. chamber, pushes iris even further forwards
RF - age, F, hypermetria (far, short eye), pupil dilatation, east Asian, anti-Ach meds, TCAs
= severe eye pain, red, blurred vision, v acuity, halos around lights, hazy cornea, semi-dilated fixed pupil, hard eyeball, worse watching tv in dark room
Inv - tonometry, gonioscopy (visualise angle)
-> urgent referral, combined drops (pilocarpine, timolol, apraclonidine) + IV acetazolamide, laser iridotomy to fix
Allergic Conjuctivitis
Cause - seasonal (pollen) or perennial (dust, detergent)
= bilateral conjunctival redness and swelling, itching, atopic history
-> top/ PO antihistamine, top mast cell stabiliser 2nd
Anterior Uveitis
Iritis, inflammation of the anterior uvea
RF - HLA B27 (IBD, ank spond, reactive arth), Behcet’s, trauma, sarcoid, syphilis, TB, cancer
= acute red eye, pain, photophobia, blurred vision, lacrimation, small irregular pupil, ciliary flush, hypopyon (fluid level due to inflam cells), floaters (pus cells)
-> urgent review, cycloplegics (atropine, cyclopentolate), steroid drops
Argyll-Robertson Pupil
Causes - syphilis, DM
= small irregular pupil, accommodates but doesn’t react to light
Holmes-Adie Pupil
Benign, ^F, issue with parasympathetic ganglion
= unilateral dilated pupil, no reaction to light, slow reaction to accommodation, may have absent knee/ ankle reflexes
Cataracts
Lens gradually opacifies
Causes - age (nuclear), smoking, alcohol, trauma, DM, long-term steroids (subcapsular), radiation, myotonic dystrophy, v Ca
= blurred vision, faded colour vision, glare and halos on lights, defect in red reflex
-> surgery based on symptoms/ QoL/ patient choice
Comp of surgery - posterior capsule thickening or rupture, retinal detachment, endophthalmitis
Central Retinal Vein /Artery Occlusion
Artery
Cause - thromboembolism or arteritis
= sudden, painless, unilateral vision loss, RAPD, cherry red spot on pale retina
Vein
RF - age, HTN, CVD, glaucoma, polycythaemia
= sudden, painless, unilateral vision loss, severe retinal bleeds seen
Corneal Disorders
= pain, sensation of foreign body, lacrimation, red
Abrasion: defect in epithelium due to local trauma, fluorescein staining
-> top Abx
Ulcer: bacterial/ fungal/ viral/ acanthamoeba keratitis
RF - contact lenses, vit A def
Foreign body
-> refer if suspect penetration, sig orbital trauma, chemical, organic material, severe pain, vv acuity
Episcleritis
Acute onset inflammation of episclera
Cause - most idiopathic, IBD, RA
= painless red eye, segmental redness
Inv - gentle pressure on sclera (mobile vessels), phenylephrine injection (redness improves)
-> conservative
Eyelid Disorders
Stye: infection of eyelid glands
-> hot compress, analgesia
Chalazion: retention cyst of meibomian gland
= firm painless lump
-> spont, drainage
Entropion: in-turning of the eyelids
Ectropion: out-turning of the eyelids
Herpes Simplex Keratitis
Commonly presents with dendritic corneal ulcer
= red painful eye, photophobia, lacrimation, v acuity
-> urgent referral, top acyclovir
Herpes Zoster Ophthalmicus
Reactivation of VZV in the ophthalmic division of trigeminal nerve, 10% shingles cases
= vesicular rash around eye, Hutchcinson’s sign (rash on nose, strong RF for ocular involvement)
-> urgent review, PO acyclovir 7-10d <72hrs, top steroids
Horner’s Syndrome
Causes
Central lesions: anhidrosis of face, arm and trunk
S - Stroke, Syringomyelia, MS
Pre-ganglionic lesions: anhidrosis of face
T - pancoast’s Tumour, Thyroidectomy, Trauma
Post-ganglionic: no anhidrosis
C - Carotid artery dissection, Carotid aneurysm, Cluster headache, Cavernous sinus thrombosis
= miosis, ptosis, enophthalmos (sunken eye), anhidrosis
Infective Conjuctivitis
Bacterial = purulent discharge, lids stuck together
Viral = serous discharge, recent URTI, preauricular nodes
-> self limiting, top chloramphenicol, fusidic acid if pregnant, don’t wear contacts
Keratitis
Inflammation of cornea, microbial is sight-threatening
Cause
Bacterial - staph aureus, pseudomonas in contact lenses
Acanthamoebic - contact lenses, soil or contaminated water (^^pain)
Also, fungal, parasitic, viral (HSV), photokeratitis (welders), exposure
= red eye, pain, gritty, foreign body sensation, photophobia
-> refer same-day if contact lenses (excl. microbial), stop wearing lenses, top Abx (quinolones), cyclopentolate for pain
Nasolacrimal Duct Obstruction
Imperforate membrane in lacrimal duct
= persistent watery eye in infant
-> massage duct, resolve by 1yr
Ocular Trauma
Hyphema: blood in anterior chamber, risk of ^IOP
-> urgent referral, bed rest
Orbital compartment syndrome: emergency
= eye pain, swelling, proptosis, hard eyelid, RAPD
-> urgent lateral canthotomy to decompress orbit
Optic Neuritis
Cause - MS (50% with ON get MS within 15yrs), DM, syphilis
= hrs-days, unilateral v acuity, red desaturation and poor colour discrimination, pain on eye movement, RAPD, central scotoma
Inv - MRI brain and orbits with gadolinium contrast
-> high dose steroids, recover 4-6wks
Orbital Cellulitis
Infection of fat and muscles posterior to the orbital septum (not involving globe), emergency
RF - 7-12yrs, no Hib vaccine, pre-septal cellulitis, facial infection
Cause - spreading URTI e.g., sinus (strep, staph, Hib)
= red swollen eye, severe pain, visual loss, proptosis, ophthalmoplegia
Inv - FBC, CT with contrast, blood culture, swab
-> admit, urgent senior review, IV Abx
Papilloedema
Optic disc swelling caused by ^ICP
Cause - space-occupying lesion (neoplasm, vascular), malignant HTN, idio IC HTN, hydrocephalus, ^CO2
Inv - fundoscopy (venous engorgement, loss of venous pulsation, blurring of disc margin, loss of the optic cup, Paton’s lines)
Posterior Vitreous Detachment
Separation of vitreous membrane from the retina
RF - age (fluid becomes more viscous), myopia (near, longer)
= no pain or vision loss, flashes and floaters
-> assessment <24hrs, no treatment, better in 6m
Pre-septal/ Peri-orbital Cellulitis
Infection of soft tissue anterior to orbital septum
Causes - staph aureus, staph epidermidis, strep
= <10yrs, red swollen painful eye, no proptosis/ visual disturbance/ ophthalmoplegia
Inv - contrast CT (excl. orbital)
-> all need hospital assess, PO co-amoxiclav
Retinal Detachment
Neurosensory tissue that lines the back of the eye separates from the pigment epithelium
RF - DM, myopia, age, prev cataract surgery, trauma
= new floaters or flashes, sudden and progressive visual field loss (curtain or shadow), painless, RAPD (if optic nerve involved), straight lines appear curved
Inv - fundoscopy (no red reflex, pale retinal folds), slit-lamp, indirect ophthalmoscopy
-> urgent referral <24hrs for new flashes/ floaters
Retinitis Pigmentosa
Inherited condition, decrease rods and cones
= night blindness, tunnel vision (loss of peripheral retina)
Inv - fundoscopy (black bone spicule pigmentation)
Scleritis
Full-thickness inflammation of the sclera
RF - RA, SLE, sarcoidosis, granulomatosis with polyangiitis
= red eye, painful, teary, photophobia, gradual v vision
-> same-day assessment, oral NSAIDs, steroids if severe
Strabismus
Squints, misalignment of the visual axes
Concomitant: imbalance in extraocular muscles (convergent > divergent)
Paralytic: paralysis of extraocular muscles
Inv - corneal light test (light 30cm from face, reflect asymmetrically), cover test
-> refer to secondary care, patches
Comp - amblyopia (brain fails to fully process inputs from one eye, favours the other over time)
Sudden Loss of Vision
Causes - amaurosis fugax (thrombus, embolus, arteritis), vitreous haemorrhage, retinal detachment, retinal migraine
Vitreous Haemorrhage
Bleeding into the vitreous humour, heals by 1% a day once bleeding stops
Causes - proliferative diabetic retinopathy, vitreous detachment, trauma
= sudden painless vision loss, red hue, floaters or dark spots
Inv - dilated fundoscopy, sit lamp (RBC in anterior vitreous)
