Ophthalmology Flashcards
What are the functions of the ciliary body?
Produces the aqueous humour, holds the lens in place & contains the ciliary muscles for accommodation.
What is it called when the ciliary muscles get older and contract less and, as a result, you cannot see close up?
Presbyopia (far-sightedness)
If there’s a foreign body in the cornea, and we remove it, how long do we wait to check up again and why?
3 days, due to the corneal epithelium taking 3 days to regenerate.
When looking at something close all of a sudden, what happens to your eyes?
Your eyes converge, pupils get smaller and the lenses get thicker.
What does RAPD mean?
Relative Afferent Pupillary Defect.
Relative = not total
Afferent = optic nerve
Pupillary defect = something has gone wrong with the pupil
When light shines on the affected eye, it dilates instead of constricting.
What is a normal optic disc to cup ratio?
< 0.5
What is photopsia?
Flashes of light or fireworks
What is metamorphopsia?
Distortion of objects or shapes
What is dyschromatopsia?
Change in colour perception
What is the sinus inferior to the eye?
Maxillary sinus
What is the sinus superior to the eye?
Frontal sinus
What is the sinus lateral to the eye?
Temporal sinus
What is the sinus nasally to the eye?
Ethmoidal sinus
What’s the normal range for intraocular pressure?
10 - 21 mmHg
Guess the diagnosis: inflammation and crusting of the eyelids, worse in the heat. You can see punctate epithelial erosions on fleuroscein staining and slit lamp.
Blepharitis
What is a stye?
External; infection of gland of Zeiss OR infection of eyelash follicle
What is a chalazion?
Internal; infection then blockage of Meibomian glands
How do we manage a stye?
Warm compress, cleansing eyelid area
+/- Lubricating drops
Analgesia
Topical antibiotics if there’s conjunctivitis as well
How do we manage a chalazion?
Warm compress, MASSAGE, cleansing eyelid area
+/- Lubricating drops
Analgesia
Topical antibiotics if there’s conjunctivitis as well
Ahmad was doing some woodwork and an insect bit him. The next day, he woke up with unilateral ocular pain and discomfort. When he looked in the mirror, he was shocked to see the affected eye was fully swollen and he couldn’t see properly through it. When you ask him to follow your pen with a ‘H’ motion, he reports no pain, and can see all the right numbers on the Ishihara plates. What is the diagnosis?
Preseptal cellulitis.
Not orbital cellulitis due to the absence of restricted and painful extraocular muscle movement and poor colour vision.
How do we manage preseptal cellulitis?
PO Co-Amoxiclav
but if penicillin-allergic, PO clindamycin
How do we manage orbital cellulitis?
Admit
CT head
IV abx
ENT r/v
What are the red flags of orbital cellulitis?
Orbital involvement
Proptosis
Restricted and painful extraocular muscle movement
Poor visual acuity
Poor colour vision
RAPD
Sepsis
Age < 12 months
Immunocompromised
What’s the diagnosis: Painful visual loss, red desaturation, central scotoma?
Optic neuritis = optic nerve swelling
Which diseases can cause optic neuritis?
MS (most common)
Diabetes
Syphilis
How do we investigate optic neuritis?
MRI of the brain and orbits with gadolinium contrast
Guess the diagnosis: Progressive, worsened central vision, especially at night. Normal examination.
Age-related macular degeneration
How do we manage optic neuritis?
High-dose steroids
How do we investigate AMD and how would we distinguish between dry and wet?
Fundoscopy & OCT.
Fundoscopy:
Dry –> Drusen, small accumulations of extracellular material
Wet –> neovascularization –> exudates leaking and haemorrhaging
OCT:
Dry –> drusen appear as Retinal Pigmented Epithelium deformation or thickening
How do we manage dry AMD?
Supportive:
Smoking cessation
BP control
Weight loss
How do we manage wet AMD?
Conservative:
Smoking cessation
BP control
Weight loss
Medical:
Intravitreal anti-VEGF injections
What are the main painless causes of red eye?
Dry eye (evaporative dry eye = blepharitis)
Conjunctivitis –> viral, bacterial, allergic
Episcleritis
Subconjunctival haemorrhage
What is the most likely diagnosis: Painless, watery, red, gritty eye, crusted shut in the morning & swollen conjunctiva (chemosis)
Conjunctivitis
Guess the diagnosis:
Painless red eye. Clear, watery discharge, lymphadenopathy & common cold symptoms (coryza).
Viral conjunctivitis
How do we manage viral conjunctivitis?
Conservative:
Lubricating eye drops and cool compresses.
Contagious –> no sharing of towels.
If corneal involvement –> photophobia –> referral to ophthalmologist for topical steroids.
What is viral conjunctivitis commonly caused by?
Adenovirus
Guess the diagnosis:
Painless red eye, gritty, severe mucopurulent discharge & conjunctival injection. (Unilateral and non-resolving).
Bacterial conjunctivitis (associated with STIs).
How do we manage bacterial conjunctivitis?
Remove contact lenses
School exclusion not-necessary
Most cases are self-limiting, but topical chloramphenicol drops 2-3 hourly can quicken relief
If pregnant –> topical fusidic acid BD
How do we treat bacterial conjunctivitis associated with STI?
Systemic antibiotic treatment
Refer to genitourinary medicine to evaluate genital disease and contact tracing
Guess the diagnosis:
Painless red eyes, mild puffiness, chemosis, itching, history of asthma.
Allergic conjunctivitis
How do we manage allergic conjunctivitis?
Identify and reduce causative allergen
Topical lubricating eye drops
1st line: topical/systemic antihistamines
2nd line: topical mast cell stabilisers (sodium cromoglicate, nedocromil)
How do we investigate preseptal cellulitis?
CT head
Guess the diagnosis: painful red eye, blurry vision, photophobia, excessive lacrimation, lower back pain improving with exercise.
Acute anterior uveitis
(inflammation of the uvea = inflammation of the iris and ciliary body)
A patient has come in and you’ve suspected acute anterior uveitis. What are your next steps to investigate and what would you expect to see?
Examination of the eyes without fluoroscein and then with: ciliary injection, irregular pupil, corneal oedema, hypopyon
Check eye movements
Slit lamp examination: ciliary flush, aqueous cells in the anterior chamber, flare in the anterior chamber, posterior synechiae
Bloods: routine, HLA-B27 testing, infectious disease screen, serum ACE, etc.
OCT for macular oedema
Spinal X-R for ankylosing spondylitis
C-XR
VDRL
What are posterior synechiae?
Adhesions between the lens and pupil, which distort the shape of the pupil
What is known as “flare”?
Smokey/foggy appearance of the anterior chamber
What is the management for anterior uveitis?
Suspected uveitis –> refer to ophthalmologist for assessment within 24 hours
Topical steroid drops
Pupil dilating drops (cyclopentolate, atropine)
What can cause anterior uveitis?
50% cases idiopathic
50% due to other causes such as ankylosing spondylitis, reactive arthritis, psoriatic arthritis, IBD, syphilis, HIV, etc.