opthalmology Flashcards
blepharitis
inflammation of the eyelids + associated structures (skin, lashes, meibomian glands)
caused by bacteria
gen chronic and b/l.
S+S: burning, itching, crusting, foreign body sensation. contact lense intolerance.
if coralettes (10 or more) treat for mites.
RF: no strong RF.
Ix: slit lamp examination
biopsy if bad and long and atypical.
lid margin culture.
Rx: eyelid hyginene - warm compresses 2x daily. - melt the meibum.
eyelid scrub + massage.
artificial tears, opthalmic ciclosporin.
if visual changes- abs more aggresively.
if lash loss exclude eyelash tumour.
acute glaucoma
acute angle closure glaucoma
an ocular emergency– rapid increace in ocular pressure due to outflow obstruction of aqueous humour.
often a blockage of drainage canal from anterior chamber.
S+S: acute sudden onset of severe pain unilaterally, headache, with blurred vision.
rainbow halos, nausea, vom.
Rf: female, hyperopia, shallow anterior chamber, inuit or asian, age.
Ix: gonioscopy- examination of anterior chamber angle.
slit lamp examination
Rx: carbonic anhydrase inhibitors
AND/OR
topical B blocker
AND/OR
topical alpha 2 agonist
these reduce the pressure in the eye
then
lazer peripheral iridotomy (after corneal oedema resolves)
do the other eye as they prob the same.
chronic glaucoma
primary open angle glaucoma - more common than acute.
insidious onset, picked up incidentally.
b/l
raised IOP which damages optic nerve fibres.
Optometrist will diagnoise
features are raised iop, visual field defect, cupped optic disc.
Rx: treatment if IOP 24 or more + identified risk of visual impairment.
Rx 360 selective laser trabeculoplasty.
if not
generic prostaglandin eye drops.
2nd line- topical beta blocker.
macular degeneration
progressive degenerative maculopathy.
sudden onset blurring of vision OR progressive loss of vision.
progresses to central vision loss in both wet and dry forms.
leading cause of adult blindness in developed world.
drusen plaques (proteins and fats) go under the retina.
wet- gives neovascularisation
dry is degen of macule.
small drusen (63 or less) are normal aging. bigger is pathologic.
Rf: age, smoking, family history.
Ix: amsler grid, optical coherence tomography.
Rx: based of scoring system - no drusen or small - level 1
level 2- a few larger ones or mild retinal pigment abnormalities.
no treatment for first stages other than lifestyle.
level 3- one larger than 125, or multiple medium size ones. or artophy.
advances (4+) dry- nothing
advanced wet- intravitreal vascular endothelial growth factor inhibitors. - ranibizumab e.g.
if those fail some lazer wizardry.
benign eyelid lesions
The most common causes of benign eyelid lesions are:
Inflammation of a blocked gland (e.g., chalazion)
Infection and inflammation of a gland (e.g., hordeolum)
Lipid accumulation in the dermis (e.g., xanthelasma)
Cyst formation of adnexal or epidermis structures (e.g., epidermal inclusion cyst)
Melanocyte proliferation in the dermis and epidermis (e.g., nevus)
The proliferation of cells in the epidermis (acanthosis) and hyperkeratosis (e.g., seborrheic keratosis, acrochordon/skin tag)
Infection of the epidermis (usually viral, e.g., verruca vulgaris, molluscum contagiosum)
ix, rx of benign eyelid lesions
ask about risk factors for serious conditions (immunosuppression etc)
biopsy, scan if needed, photograph.
Rx: if its skin or melanocytic- quire possibly excise, but there are exceptions.
hot compress/ topical treatments. otherwise.
80% are benign but do need to biopsy.
cataracts
most common cause of preventable blindness in the world.
opacification of the crystalline lens
caused by: age, trauma, metabolic disorders, medications, congenial conditions.
decrease in visual acuity, that cannot be corrected by corrective glasses. + an opacification of the lens with an otherwise normal eye exam.
Rf: age, female, uv, smoking, dm, trauma, myopia.
Ix: dilated fundus examination. glare test, slit lamp test.
Rx: surgical lens replacement.
central retinal artery occlusion
sudden, painless, vision loss that occurs over seconds- complete loss with no light perception.
depending on branch either whole or partial loss.
Rf: as per stroke risk factors.
assoc with GCA, need good control of that to minimise risk of this.
Ix: optical coherence tomography- hyperreflectivity and edema.
Fluorescein angiography - sluggish filling.
rx: transfer to stroke centre urgently
Rx:
occular massage (press 10s hold 5s)
dilate arteries
reduce eye pressure.
residual eye loss is usually severe and permanent. damage occurs after just 100 mins of occlusion.
central retinal vein occlusion
more common than artery.
70% of cases non ischaemic– good visual acuity, a mild or no pupillary defect, and mild visual changes. half resolve on own.
ischamic- can be a progression of non. poorer prognosis, at least 10 areas of retinal capillary nonperfusion.
S+S; painless vision loss, afferent pupillary defect, colour vision loss,
bloos and thunder apperance on fundoscopy- hemm with oedema.
Ix: fluoresin angiogram
0.8 per 1000
Rx: observe + support
van inject VGE inhibitors.
diabetic retinopathy
glycosylation of blood vessels leading to growth, bleeding and scarring over and over
get exudate, haemorrhages, microaneurysms, cotton wool spots.
haemorrhage causes changes - floaters up to complete loss.
macular edema causes central vision loss, most common cause of blindness.
categorised 1-5.
1- health eyes.
5- retinal neovascularisation(proliferative)
4- is more aneurismal- non-proliferative
Picked up on screening usually.
Rf: duration of diabetes, control of sugar
Rx: proliferative – 1st line * panretinal photocoagulation
-2nd line- vegf inhibitors
- vitrectomy if not cleared after 3 mo of treatment.
if non proliferative- frequent eye exams.
giant cell arteritis
large and medium artery vasculitis. over 50, headache, +/- temporal tenderness.
+/- vision disturbances, loss of colour vision, diplopia.
Ix: non specific fundoscopy changes pallor and oedema of the optic disc, and ‘cotton-wool’ patches and small haemorrhages in the retina
crp, biopsy of temporal artery, USS.
strongly associated with PMR.
Rx: without visual symptoms is 40–60 mg oral prednisolone per day.
Iv steds if visual changes, or 60-100mg pred if not near a hospital
continue for 2 years tapering treatment.
hypertensive retinopathy
3 phases of disease- vasoconstrictive- increased flow leads to vasospasm to mediate perfusion and pressures in the eye.
sclerotic- arteries harden under the pressure
exudative phase, disruption of the blood-brain barrier + leakage of plasma + blood causing retinal haemorrhages, hard exudates, retinal ischemia, and necrosis of smooth muscle.
Ix: clinical appearance on dilated fundoscopic exam. - heamorrhage or cotton wool spots.
fluroescin angiography
Rx: control the blood pressure.
infective keratitis
infection of the cornea gen the epithelial layer
can be viral, fungal, bacterial, contact lense induced.
herpes can cause- may become recurrent
S+S: red eye, forgien bod feeling, photophobia, vesicles, discharge.
Ix: slit lamp examination, with fluorescin staining. —- DENDRITIC ulcer seen.
Rx: dependant on cause- topical / oral anti virals (acyclovir) biotics or fungals as appropriate
corneal transplant if the scarring is mega.
irititis
AKA anterior uveitis- inflammation of the iris or anterior chamber
mostly idiopathic (20% trauma)
associated with HLA-B-27 diseases- juvinile arthritis, AS, UC, SLE.
young + middle ages affected
S+S: pain, red, photophobia, decreaced visual acuity– pain develops slowly.
Ix: slit lamp examination- FLARE and CELL apperance (inflam and WBC)
Rx: refer to opthal
topical roids (eye drops)
what nerves do which eye movements
occular motor- eyelids, eyes up and down, inward, pupil
trochlear nerve- down and in/ out
abducens nerve- lateral rectus- abduction
