ophthalmic lecture Flashcards
anterior segment contains
orbits, lids/lashes, cornea, conjunctiva,sclera, anterior chamber/aqueous humor, iris, pupil
posterior segment
posterior vitreous, optic nerve, macula/fovea, peripheral retina, vessels (arteries and veins)
segment b
lens and ciliary body
LR6 +SO4+EE3
lateral rectus CN6 (abducens)
superior oblique CN 4 (trochlear)
everything else CN3 (oculomotor)
meibomian glands purpose
secrete the oil layer to our tear film, oil prevents tears from evaporating
the cornea is filled with
thousands of tiny nerve endings that make the cornea extremely sensitive to pain.
The pathway for the outflow of aqueous humor.
Aqueous humor produced by ciliary body -> flows through the pupil into the anterior chamber -> flows out through the trabecular meshwork into the canal of schlemm -> absorbed into the episcleral veins via the collector channels.
macula is in charge of our
central vision
also contains pigmented cells called cones
optic nerve is in charge of
our peripheral vision
periorbital (preseptal) cellulitis
define
s/s
tx
- Bacterial infection of eyelid anterior to orbital septum that occurs 2° to sinusitis, trauma, ocular Sx, hordeolum, etc.
- s/s = eyelid tenderness, erythema, and edema; (-) proptosis, (-) pain on EOMs, (-) vision changes
- Tx = Mild = PO Abx (amoxicillin, Bactrim); moderate - severe = hospital admission + IV Abx (vancomycin, clindamycin, cefotaxime)
orbital (septal) cellulitis
define
s/s
tx
- Bacterial infection that occurs Most commonly 2° to sinusitis
- s/s = eyelid tenderness, erythema, and edema; (+) proptosis (bulging), (+) pain on EOMs, (+) decreased vision
- Tests = assess EOMs, CT scan (infection of the orbital fat and EOMs), CBC with diff
- Tx = hospital admission + broad spectrum IV abx
dacrocytitis
bacterial infection of the lacrimal sac
most common is staph aureus
dacrocytitis s/s
pain, erythema and edema over lacrimal sac/medial canthus (nasal side of the lower lid)
orbital blowout fractures
the force from a direct traumatic blow to the eye, - a fracture of thin bones of the orbital floor
orbital blowout fracture complications
the contents of the orbit EOM, fat ect, can get entrapped which leads to the following :
decreased visual acuity, diplopia (especially upward gaze if there is inferior rectus entrapment), restricted eye movement, ptosis
orbital blowout fracture s/s
pain, tenderness, orbital emphysema (eyelid swelling after blowing nose), ecchymosis
ectropion
eyelid turned outwards
most common in elderly and aging
ectropion s/s & tx
- irritation, tearing (epiphora), foreign body sensation
- artificial tears, blepharoplasty
entropion
eyelid turned inward
most common in elderly and aging
entropion s/s & tx
irritation, tearing (epiphora) foreign body sensation, corneal abrasions- leads to pain and vision changes
tx: artificial tears and blepharoplasty
hordeolum-internal
inflammation/bacterial infection of a meibomian gland
hordeolum-external
inflammation/bacterial infection of the glands of zeis