Ophthalmic presentations Flashcards
What is photopsia?
Light flashes without a light source
What are some causes photopsia?
- posterior vitreous detachment
- migraine with aura
- migraine aura without headache
- retinal break or detachment
What is posterior vitreous detachment?
The separation of the posterior vitreous cortex and the internal limiting membrane of the retina
(The layers peel apart)
What causes retinal detachment?
Ageing
Injury of the eye
What are the different types of retinal detachment?
- rhegmatogenous: caused by a hole or tear in the retina that allows fluid to pass through and collect underneath the retina causing the retina to pull away from underlying tissues
- Tractional: scar tissue allow separation like in diabetes mellitus
- Exudative: when fluid builds up between the layers
What are vitreoretinal diseases?
Diseases that affect the structure of the eye
Eg. macular degeneration, retinal tears, retinal detachment, macular holes, and diabetic retinopathy
What is laser-assisted in situ keratomileusis (LASIK)?
It changes the shape of your cornea to improve how light hits your retina
What is photorefractive keratectomy (PRK)?
A laser refractive procedure used to ablate the corneal stroma to correct refractive errors
What is upper eye lid eversion?
Can be congenital and needs surgical treatment
Essential in examination of the upper palpebral conjunctivas
What is an anterior chamber depth assessment?
Tests the space between the cornea and the iris
Done by shining a light at the temporal side of the eye, is there is a shadow on the nasal iris then it suggests a shallow anterior chamber
Done is glaucoma diagnosis
How are foreign bodies removed from the eye?
- Assess visual acuity
- Put anaesthetic drops in
- Remove object
May need referral to an ophthalmologist is deep or central
How can pupils be dilated?
Cyclopentolate drops
Other causes:
- Recreational drugs
- Dim lighting
- Reaction to medication
- Adrenaline
- Sexual arousal
- Brain injury
What is Mydriasis?
Dilated pupils
How is intraocular pressure assessed?
By applanation tonometry
Estimates pressure based on the resistance to flattening of the small area around the cornea
What is fluorescein staining used for?
Checking for corneal or vessel abnormalities
It diffuses into intraocular spaces resulting in staining
Which tests confirm multiple sclerosis?
MRI to look for plaques in the CNS
Which tests confirm giant cell arteritis?
- Biopsy (gold standard)
- Bloods to show elevated ESR or CRP
- A scan of the aorta and it’s branches
Eg. CT with angiography or MRI with angiography
Which tests confirm Guillian-Barre syndrome?
- Spinal tap (show elevated protein levels, which reflects the widespread inflammation, and normal WBC’s)
- Electromyography
- Nerve conduction test
Clinical findings: reduced reflexes
What is Electromyography?
Measures muscle response or electrical activity in response to a nerve’s stimulation of the muscle
Which tests confirm myasthenia gravis?
Anti-acetylcholine receptor (AChR) antibody (Ab) blood test
Which tests confirm meningitis?
- A spinal tap. Will show low sugar levels with increased WBC’s and increased proteins
- MRI helps evaluate complications
Analysis of CSF will show the causative organism
Which tests confirm viral encephalitis?
- Lumbar puncture
- Imaging like MRI or CT
Which tests are done to confirm Bell’s Palsy?
No confirming tests, just tests to exclude other causes
Eg. Bloods to exclude infection, Ct/MRI to exclude structural causes, EMG to determine extent of nerve involvement
Which tests confirm herpes zoster infection?
- PCR
- Swabs from lesions
What other diseases in myasthenia gravis associated with?
- Autoimmune disease like rheumatoid arthritis, SLE
- Hypertension, heart disease, diabetes, respiratory diseases, dyslipidemia
- Teratoma
- Thymoma (cancer of the thymus)
What is cerebral salt wasting syndrome?
Renal loss of sodium during intracranial disease leading to hyponatremia and a decrease in extracellular fluid volume
What are some causes of ptosis?
- 3rd nerve palsy
- Horner’s syndrome
- Age
- Myasthenia gravis
- Chronic progressive external ophthalmoplegia (mitochondrial myopathy)
How does thyroid disease affect the eyelid?
Causes retraction of eyelids making it look like you’re staring
What is papilloedaema?
Optic disc swelling specifically due to raised intracranial pressure
Often refers to a swollen disc
What is bone-spicule pigmentation of the retina?
Migration of pigment into the interstitial spaces
(Black markings around the borders of a fundoscopy image)
What is retinitis pigmentosa?
A group of rare eye diseases that affect the retina
Triad of symptoms:
- arteriolar attenuation
- bone–spicule peripheral retinal pigmentation
- waxy optic disc pallor
What is arteriolar attenuation?
Narrowing of blood vessels at the back of the eye
A defining sign of hypertensive retinopathy
