Ophthal 2 Flashcards
Left congruous homonymous hemianopia visual field defect - where is the lesion?
If it’s incongruous?
Right optic radiation or, occipital cortex (esp if there’s macula sparing)
Incongruous: Right optic tract
Inferior homonymous quadrantanopia - where is the lesion?
Parietal lobe
Superior homonymous quadrantanopia - where is the lesion?
Temporal lobe
Congruous (complete or symmetrical) visual defect - where is the lesion?
Incongruous visual defect - where is the lesion?
Congruous: optic radiation or occipital cortex
Incongruous: optic tract lesion
Bitemporal hemianopia where the upper quadrant defect > lower quadrant defect?
Inferior compression of the optic chiasm - e.g. pituitary tumour
Bitemporal hemianopia where the lower quadrant defect > upper quadrant defect?
Superior compression of the optic chiasm - e.g. craniopharyngioma
What is infection of the lacrimal sac i.e. watering eye with swelling & erythema at the inner canthus?
Rx?
Dacrocystitis
- systemic Abx, IV if periorbital cellulitis
Eye drops that reduce aqueous production?
- beta-blockers
- sympathomimetics (also increase outflow)
- carbonic anhydrase inhibitors
Eye drops that increase uveoscleral outflow?
- prostaglandin analogues
- sympathomimetics (also reduce aqueous production)
- miotics
Eye drops administered once daily that increase uveosacral outflow but can cause brown pigmentation of the iris?
prostaglandin analgues eg Latanoprost
Eye drops that reduce aqueous production but should be avoided in asthmatics & pts with heart block?
beta blockers eg timolol
Eye drops that should be avoided if taking MAO-I or TCAs and can cause hyperaemia?
Sympathomimetics e.g. Brimonidine (alpha2 agonist)
- reduce aqueous production & increase outflow
Eye drops that reduce aqueous production and if systemically absorbed can cause sulphonamide-like reactions?
carbonic anhydrase inhibitors eg Dorzolamide
Eyedrops that increase uveoscleral outflow but can cause headache, blurred vision, and a constricted pupil?
Miotics eg Pilocarpine, a muscarinic agonist
How to classify glaucomas? (optic neuropathies usually ass with raised IOP)
- peripheral iris is covering the trabecular meshwork (important in the drainage of aqueous humour from anterior chamber of the eye)
- Open-angle glaucoma: iris is clear of the meshwork. the trabecular network functionally offers an increased RESISTANCE to aqueous outflow, causing increased IOP
Open-angle glaucoma: Sx & signs?
Case finding?
- aSx for a while when slow rise in IOP, presents after its measured by optometrist
- increased IOP
- visual field defect
- pathological cupping of the optic disc
- optic nerve head damage visible under slit lamp
- visual field defect
- IOP>24mmHg
- provisional Dx/case finding by optometrist
- ophthal referral by GP
Dx/Ix of 1ry open angle glaucoma?
- automated perimetry to assess visual field
- slit lamp exam with pupil dilatation to assess optic nerve & fundus for a baseline
- applanation tonometry to measure IOP
- central corneal thickness measurement
- gonioscopy to assess peripheral anterior chamber configuration & dephth
- assess risk of future visual impairment (IOP, central corneal thickness, FHx, life expectancy etc)
1ry open angle glaucoma: 1st line Rx?
2nd?
if more advanced?
reassessment?
1st: PROSTAGLANDIN ANALOGUE
2nd: beta-clocker, carbonic anhydrase inhibitor or sympathomimetic
if more advances consider surgery/laser Rx
- important to exclude progression & visual field loss - do more frequently if IOP uncontrolled, pt is high risk, or there is progression
- surgery eg trabeculectomy if refractory
Central lesion (1st order neutron) causes of Horner’s syndrome?
Stroke Syringomyelia MS Tumour Encephalitis - anhidrosis of face, arm, trunk
Pre-ganglion lesion (2nd order neutron) causes of Horner’s syndrome?
- anhidrosis of face Pancoasts tumour Thyroidectomy Trauma Cervical rib
Post-ganglionic lesion (3rd order neutron) causes of Horner’s syndrome?
- no anhydrosis Carotid dissection Carotid aneurysm Cavernous sinus thrombosis Cluster headache
Degeneration of retinal photoreceptors leading to Drusen - yellow round spots in Bruchs membrane, alteration to reinal-pigment epithelium
Dx?
Dry AMD or early
Degeneration of retinal photoreceptors leading to choroidal neovasculisation with leakage of serous fluid & blood that can rapidly cause loss of vision i.e. neovascularisation, exudative. Dx?
Wet AMD
- late
RFs of AMD?
Sx & signs?
- age
- smoking
- male 2:1
- FHx
- CVD RFs
- reduced visual acuity esp near field objects or at night
- difficulties in dark adaptation
n- fluctuations in visual disturbance - photopsia & glare
- distortion of line perception on Amsler grid testing
- duress which may become a macular scar
- well demarcated red patches which represent intra-retinal or sub-retinal fluid leakage or haemorrhage (wet AMD)
Ix in AMD?
Slit-lamp: pigment, exudate, haemorrhage etc, with colour fundus photo for baseline
Fluoresceine angiography: if neovascular suspected, to guide anti-VEGF Rx, may be complemented with indocyanine green angio to visualise changes in choroidal circulation
Ocular coherence tomography: visualise retina in 3 dimensions
Rx of dry & wet AMD?
Dry: antioxidants can help esp with most extensive drusen, c/i in smoking
Wet: anti-VEGF can stabilise/limit progression/reverse, within first 2months of Dx e.g. Ranibizumab, Bevacizumab, Pegaptanib. 4wkly injection
(Laser photocoag can slow progression where there is novas but risk of acute visual loss after Rx, esp in sub-foveal AMD)
RFs for 1ry open angle glaucoma?
- age
- genetics/FHx
- myopia ie SHORT sightedness
- black pts
- HTN
- DM
- corticosteroids
Features of 1ry open angle glaucoma?
what is seen on fundoscopy?
- peripheral visual field loss where nasal scooters progress to tunnel vision
- decreased visual acuity
- optic disc cupping
- increased cup to disc ration >0.7 (loss of disc substance makes optic cup widen & deepen)
- pallor of disc (atrophy)
- Bayonetting of vessels (vessels have breaks as they disappear into deep cup & re-appear at the base)
- Cup notching, usually inferior, Disc haemorrhages
Rx of herpes zoster ophthalmicus?
- oral antivirals/aciclovir 7-10days within 72h
- urgent ophthal review
(oral steroids may reduce duration of pain but not incidence of neuralgia post-herpetic)
Flashers (photopsia) in peripheral vision & floaters in temporal side of central vision
Dx?
Posterior vitreous detachment
- ophthal review to assess risk of progressing to retinal detachment
dilated pupil that reacts slowly to accommodation and once constricted remains small for an abnormally long time
- v poorly if at all to light
- can be ass with absent ankle/knee reflexes
- 80% are unilateral
Holmes-Adie pupil