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