Opthamology Flashcards
(276 cards)
What are the rods of the eye responsible for?
Night/peripheral vision
What are the cones of the eye responsible for?
Detailed/colour vision
What cranial nerves are involved in some way with the eye?
2-7
As a general rule in ophthalmology if a bacteria shows on gram stain to be a gram +ve cocci, what is it?
Strep/Staph
As a general rule in ophthalmology if a bacteria shows on gram stain to be a gram -ve cocci, what is it?
neisseria
As a general rule in ophthalmology if a bacteria shows on gram stain to be a gram -ve cocci-bacilli, what is it?
H.influenzae
As a general rule in ophthalmology if a bacteria shows on gram stain to be a gram -ve bacilli, what is it?
pseudomonas
What are the common causes for bacterial conjunctivitis in neonates?
Staph aureus Neisseria gonnorrhoea (from mother) Chlamydia trachomatis (from mother)
What should be done for all cases of neonatal bacterial conjunctivitis?
Refer immediately to ophthalmology
In all ages except from neonates, what are the commonest causes of bacterial conjunctivitis?
Staph aureus
Strep pneumoniae
H.influenzae (esp. in children)
What is the treatment for bacterial conjunctivitis?
Swab and culture for sensitivity
Topical antibiotic = chloramphenicol qds
When should chloramphenicol be avoided?
In a patient with a history of allergy, or aplastic anaemia
Treatment bottles for bacterial conjunctivitis can be easily contaminated, what is a common contaminent?
Pseudomonas aeruginosa
What other bacterial causes should be considered in a bacterial conjunctivitis in contact lens users?
Pseudomonas aeruginosa
Acanthamoeba
What viruses commonly affect the conjunctiva?
Adenovirus
Herpes simplex
Herpes zoster
How would an adenovirus conjunctivitis present?
Red, swollen conjunctiva and watery eyes
How would a conjunctivitis caused by Herpes simplex present?
Small pustules in the lateral corner of the skin around the eye
How would a conjunctivitis caused by Herpes zoster present?
Eye involved in a shingles pattern (if tip of nose is affected then this indicated more serious eye involvement)
When should a chlamydial conjunctivitis be suspected?
More chronic history
Unresponsiveness to classical treatments
Bilateral
May of may not have genital symptoms
How would a chlamydial conjunctivitis present?
Watery, slightly red conjunctiva and sclera
Follicular nodules on the underside of the upper and lower eyelids (subtarsal)
If untreated may lead to subtarsal scarring which makes blinking painful and scratchy
How would a bacterial keratitis present?
A yellow, pussy nodule +/- white cells collecting at the bottom of the sclera (hypopyon)
If lies over pupil then may affect vision
How is bacterial keratitis treated?
Hospital admission for hourly eye drops
How would a herpetic keratitis present?
Dendritic ulcer which shows up on fluorescein studies
Eye is slightly watery
May be very painful and may recurr (less painful with each recurrence)
What treatment should NEVER be given in herpetic keratitis and why?
Steroids - may cause corneal melt and perforation