The Eyes Flashcards
Ophthalmic history: redness
Associated factors, e.g. watering, discharge- mucopurulent discharge suggests bacterial infection.
Pain- sharp, dull? aching- anterior segment inflammation, acute glaucoma.
Foreign body sensation- epithelial defect, foreign body.
Photophobia.
Blurred vision.
Contact lens wear.
History of trauma.
Ophthalmic history: diplopia
Is it actually double or blurred? Duration/age of onset. Monocular or binocular? Variable or constant? Horizontal, vertical, or mixed? - horizontal = III, VI nerve palsies. - vertical = IV nerve palsy. - variable = myasthenia gravis. - progressive = thyroid eye disease.
Ophthalmic history: visual loss
Unilateral or bilateral?- uniocular = suggestive of ocular or optic nerve pathology; binocular = lesions at or posterior to the optic chiasm.
Extent: severe visual loss can occur with optic neuropathies; unilateral, segmental visual loss = retinal disorders such as retinal detachment and branch retinal vein occlusion.
Speed of onset: sudden suggests ischaemic changes, gradual is more typical of compressive causes, progression over a few hours to days can occur in optic neuritis.
Ophthalmic history: colour vision abnormalities
Often a feature of optic nerve disease.
Congenital red-green colour discrimination deficiency is seen in 5-8%.
Blue-yellow is rarely due to congenital colour deficiency so a causation should be sought.
Ophthalmic history: flashing lights
Photopsia is the perception of light in the absence of a light stimulus.
Monocular or binocular?- monocular is typically due to vitreoretinal pathology, binocular is usually a cortical phenomenon.
Causes:
-Mechanical retinal stimulation (posterior vitreous detachment, tears) or external compression.
-Subretinal pathology (choroidal neovascularisation, uveitis, choroidal tumours).
-Cortical ischaemia.
-Visual hallucinations.
Ophthalmic history: symptoms to ask about
Redness. Diplopia. Visual loss. Colour vision abnormalities. Flashing lights. Glare. Haloes or starbursts. Floaters. Night-driving problems. Increased myopia.
Ophthalmic history: causes of eye pain
Gritty, sharp pain: corneal epithelial defect (abrasion, keratitis).
Ache, photophobia: iritis.
Pain on eye movement: optic neuritis.
Scalp tenderness, jaw claudication: temporal arteritis.
Nausea, vomiting: acute angle closure glaucoma, raised intracranial pressure (papilloedema).
Ophthalmic history: causes of floaters
Weiss ring following posterior vitreous detachment.
Vitreous condensation.
Vitreous haemorrhage.
Liberated pigment cells associated with retinal tears.
Inflammatory cells.
Tumour cells.
Asteroid hyalosis.
Ophthalmic history: systems enquiry
Use this to explore symptoms that may point to a systemic disease with ocular manifestations.
MS: weakness, paraesthesia, bladder dysfunction.
Thyroid eye disease: heat intolerance, weight loss, irritability, anxiety.
Myasthenia gravis: dysphagia, weakness worse at the end of the day.
Embolic disease: atherosclerotic disease, arrhythmias.
Acoustic neuroma: hearing loss, tinnitus, balance problems.
Rheumatological and collagen vascular disease: arthralgia, rashes.
Ophthalmic history: past medical history
Diabetes.
Hypertension.
Atopy (allergic conjunctivitis).
Rheumatological disease (dry eye, corneal melt, scleritis).
Neurological diseases (VII palsy, exposure keratopathy).
Metabolic disease (hypercalcaemia).
Ophthalmic history: past ocular history
Past ophthalmic surgery: intraocular (endothelial dysfunction) or refractive (post-laser-assisted stromal in situ keratomileusis LASIK, dry eye, flap dehiscence).
Does the patient wear glasses?
Does the patient wear contact lenses? type? overnight wear? cleaning regimen? swimming?
Trauma (physical, chemical, radiation).
Infection: herpes simplex keratitis, herpes zoster ophthalmicus.
Ophthalmic history: drug history
Topical steroid (cataract, glaucoma, herpetic geographic ulcer).
Toxicity to preservatives/drop allergy.
Ethambutol, isoniazid, amiodarone, and ciclosporin can cause optic neuropathy.
Recreational drug use- particularly in atypical pupil abnormalities.
Ophthalmic history: family history
FHx of MS common in patients with optic neuritis.
Contact with infection, conjunctivitis.
Inherited corneal dystrophies.
Glaucoma.
Ophthalmic history: family ophthalmic history
Ask about any eye diseases which run in the family, e.g. glaucoma, inherited retinal dystrophies.
Ophthalmic history: social history
Occupation and hobbies: for visual requirements, e.g. sports, driving, reading.
Country of previous residence (sun exposure, poor sanitation).
Lead and carbon monoxide can cause optic nerve dysfunction.
STD? e.g. syphilis, HIV/AIDS.
Ophthalmic history: causes of diplopia
Horizontal: VI nerve palsy.
Vertical: IV nerve palsy.
Mixed: III nerve palsy.
Mechanical: thyroid eye disease, trauma (orbital wall/floor fracture), idiopathic orbital inflammatory disease, tumour.
Myasthenia gravis.
Decompensating phobia.
Monocular: high refractive disparity between eyes (anisometropia, astigmatism), corneal opacities or ectasias, lens subluxation, iris defects (trauma, laser peripheral iridotomies).
Visual acuity: visual axis, applied anatomy
Light passes through the cornea, anterior chamber, pupil, lens, and vitreous chamber before hitting the retina.
The optic nerve begins at the retina (and is the only part of the CNS that can be directly visualised).
The nerve passes through the optic foramen and joins its fellow nerve from the other eye at the optic chiasm just above the pituitary fossa.
Here, the fibres from the nasal half of the retina decussate.
They continue in the optic tract to the lateral vehicular body.
From there, they splay out such that those from the upper retina pass through the parietal lobe and the others through the temporal lobe.
Fibres from the nasal halves of the retinas cross, so the left side of the brain receives init from the right side of vision (left temporal retina and right nasal retina) and vice versa.
Visual acuity: testing visual acuity
Snellen chart.
In good light conditions, stand the patient 6m from a Snellen chart.
Test each eye in turn unaided or with the glasses they normally use for distance vision.
Repeat the test with a pinhole.
Any improvement in vision implies an uncorrected refractive error (rather than ocular pathology).
Record the lowest line that can be read (allow 2 errors per line).
The number associated with the letters indicates the distance from which a person with normal sight would be expected to read.
Record the visual acuity as the distance from the chart followed by the number at the lowest letters read.
If the patient is unable to see the Snellen chart at all, see if they can count fingers (CF), see hand movements (HM), see light (PL)- if the patient is unable to see light then record as NPL.
Causes of visual loss: cornea
Dry eyes. Corneal abrasion. Corneal ulcer. Herpetic keratitis. Corneal oedema (acute angle closure glaucoma). Keratoconus.
Causes of visual loss: anterior chamber
Iritis.
Hyphaema.
Hypopyon.
Causes of visual loss: lens
Cataract.
Causes of visual loss: vitreous chamber
Vitreous haemorrhage.
Vitritis.
Causes of visual loss: retina
Branch/central artery or vein occlusion. Retinal detachment. Macular degeneration. Macular oedema. Hypertensive retinopathy.
Causes of visual loss: optic nerve
Optic neuritis.
Ischaemic optic neuropathy.
Papilloedema.
Causes of visual loss: optic chiasm
Pituitary tumour.
Meningioma.
Causes of visual loss: optic tract
CVA.
Tumour.
Causes of visual loss: occipital cortex
CVA.
Tumour.
Skills station, model technique: examine this patient’s optic nerve function
Clean your hands.
Introduce yourself.
Explain the purpose of the examination, obtain informed consent.
Sit facing the patient.
Measure visual acuity for distance and near with Snellen chart and something to read up close.
Measure colour vision (Ishihara colour plates).
Check for an RAPD (relative afferent pupillary defect).
Examine the optic disc looking for any disc swelling, haemorrhage, atrophy, collateral vessels, and cupping.
Perform perimetry (confrontation, manual, automated) to detect any characteristic field defects.
Thank the patient.
Visual fields: testing the visual field, for gross defects and visual neglect (inattention)
Sit opposite the patient, 1m apart, eyes level.
Test first for gross defects and visual neglect with both eyes open.
Ask the patient to look directly at you, ‘look at my nose’.
Ask ‘is any part of my face missing?’
Raise your arms up and out to the sides so that one hand is in the upper right quadrant of your vision and one in the upper left.
Move one index finger and ask the patient, whilst looking straight at you, to point to the hand which is moving.
Test with the right, left, and then both hands.
Test the lower quadrants in the same way.
If visual neglect is present, the patient will be able to see each hand moving individually but report seeing only one hand when both are moving (compare with sensory inattention).
Visual fields: testing each eye
Sit opposite the patient, 1m apart, eyes level.
Ask the patient to cover their right eye while you close your left and ask them to look into your right eye.
Test each quadrant individually.
Stretch your arm out and up so that your hand is just outside your field of vision, an equal distance between you and the patient.
Slowly bring your hand into the centre, wiggling a finger, and ask the patient to say ‘yes’ as soon as they can see it.
Make sure they keep looking at your right eye.
You should both be able to see you hand at the same time.
Test upper right and left, lower right and left individually, bringing your hand in from each corner of vision at a time.
Map out any areas of visual loss in detail, finding borders- test if any visual loss extends across the midline horizontally or vertically.
Test each eye in turn, then again with a red pin to map ut areas of visual loss in more detail.
Common visual field defects
Tunnel vision. Enlarged blind spot. Unilateral visual loss. Scotoma. Bitemporal hemianopia. Binasal hemianopia. Homonymous hemianopia. Homonymous quadrantanopia.
Common visual field defects: tunnel vision
A constricted visual field (glaucoma or retinal damage).
Tubular vision is often functional.
Common visual field defects: enlarged blind spot
Caused by papilloedema.
Common visual field defects: unilateral visual loss
Blindness in 1 eye caused by devastating damage to the eye, its blood supply, or optic nerve.
Common visual field defects: scotoma
A ‘hole’ in the visual field (macular degeneration, vascular lesion or toxins).
If bilateral, may indicate a very small defect in the corresponding area of the occipital cortex (e.g. MS).
Common visual field defects: bitemporal hemianopia
The nasal half of both retinas and therefore the temporal half of each visual field is lost.
Damage to the centre of the optic chiasm such as pituitary tumour, craniopharyngioma, suprasellar meningioma.
Common visual field defects: binasal hemianopia
The nasal half of each visual field is lost (rare).
Common visual field defects: homonymous hemianopia
Commonly seen in stroke patients.
The right or left side of vision in both eyes is lost, e.g. the nasal field in the right eye and the temporal field in the left eye.
If the central part of vision (the macula) is spared, the lesion is likely in the optic radiation.
Without macular sparing, the lesion is in the optic tract.
Common visual field defects: homonymous quadrantanopia
Corresponding quarters of the vision are lost in each eye.
Upper quadrantanopias suggest a lesion in the temporal lobe.
Lower quadrantanopias suggest a lesion in the parietal lobe.
Pupil abnormalities
Relative afferent pupillary defect (RAPD).
Horner’s syndrome.
Argyll Robertson pupil.
Holmes-Adie-Moore syndrome, Adie’s pupil.
Pupil involving 3rd nerve palsy.
Pupil abnormalities: relative afferent pupillary defect (RAPD)
This results from lesions in the anterior visual pathway.
Corneal opacities or cataract do not cause a RAPD.
Causes:
- optic neuropathy, e.g. optic neuritis, compressive lesions.
- gross retinal pathology, e.g. central retinal vein occlusion CRVO, retinal detachment.
- optic chiasm and tract lesions- infarcts, demyelination.
Pupil abnormalities: Horner’s syndrome
Oculosympathetic palsy (interruption of the cervicothoracic sympathetic chain at a 1st, 2nd, or 3rd order neuron level).
Multiple causes, depending on site of lesion.
Unilateral mild ptosis.
Ipsilateral anhydrosis.
Ipsilateral iris heterochromia if congenital or long-standing.
Mild miosis.
Normal or slight delay of pupillary dilatation.
No relative afferent pupillary defect.
Pupil abnormalities: Argyll Robertson pupil
Caused by neurosyphilis.
Constricted and irregular pupils (asymmetric).
No reaction to light.
Brisk constriction to accommodation.