RRCC Ophthalmology Pt I II and III Flashcards
Where do tears come from?
lacrimal gland
Muscous glands scattered throughout conjunctiva produce mucous which mixes watery portion to create protective film
Where do tears drain?
Upper and lower puncta. Move into short canal called canaliculus to the nasolacrimal duct into the nose.
Function of the iris
Thin circular structure of the eye responsible for controlling the diameter and size of the pupil and amount of light reaching the retina
Function of pupil and associated muscles/innervations
dilates and contricts to allow more or less light to the retina.
Dilator pupillae innervated by sympathetic system (CN V1 branch of optic nerve)
sphincter pupillae (constrict) parasympathetic system (CNIII)
Conjunctiva
the mucous membrane that covers the front of the eye and lines the inside of eyelids.
Contains blood vessels
Aqueous humor
- Where produced?
- What does it flow through/ reabsorb?
- Produced by ciliary body by diffusion and active transport plasma
- flows through the pupil and fills the anterior chamber. Reabsorbs by trabeculae in the canal of schlemm
Function of cornea
transparent portion over the iris and pupil that protects the structures and help to transfer and focus light on the retina.
Viterous chamber
space b/w the lens and the retina that is filled with clear gelatinous material (vitreous humor)
Retina
thin layer of tissue that lines the back of the eye and contains photoreceptors and blood vessels to nourish them
What are cones and rods
photoreceptors
Cones are responsible for sharp, detailed central and color vision. Found in the macula
rods are responsible for night and peripheral vision
There are more rods than cones
What forms the blind spot?
optic nerve exits the back of the eye through the optic disk. Since no receptor cells are located in this region, it forms a blind spot in the visual image of the external world. This blind spot is easily compensated for by primary visual cortex with information obtained from the opposite eye.
Function of the levator palpebrae
Keeps eye open
Rule of thumb:
eye= which CN?
CN III
Anterior Blepharitis
- Name with viral and bacterial causes
- Tx
inflamm of eyelids. Bilateral if lid margins
- Causes: S. aureus or S. epidermititis (viral-dry scales, redness of lid margins, irritation, burning, itching)
seborrheic (bacterial- greasy scales, burning, itching)
- Keep eyelids clean, remove scales with hot wash cloth/baby shampoo.
Antistaph abx or Sulfonamide eye ointment
Posterior Blepharitis
1 dx
- tx
- chronic bilateral inflamm of eyelids secondary to dysfunction of the Meibomian glands
Strong association with acne rosacia
Hyperemic lid margins with telangiectasias (dilated small blood v.)
- Abx may be needed in more chronic cases
External Hordeolum
- define
- sx/sxs
- tx
- Staph infection
Stye: small and on the margin, ACUTE
- localized redness/swelling/acute tenderness involving the upper/lower lid
- warm compress, wash eyelid 4x/day. Incision may be needed it may lead to general cellulitis and requires immediate medical attention
Internal Hordeolum
- Define
- sx/sxs
- Tx
- Staph infxn
chalazion: meibomian gland abscess usually points to conjunctival surface of the lid. CHRONIC - localized redness/swelling/acute tenderness involving the upper/lower lid
- Warm compress/wash 4x/day/incision may be needed. Steroid inj may be used (refer to optho)
Entropion vs Ectropion
Entropion- inward turning of eyelid. Common in elderly lose elasticity. Surgery if lashes cause corneal irritation
Ectropion- outward turning of eyelid. Surgery if excessive dryness, keratitis, exposure problematic.
Pinguecula
Yellowish, slightly raised conjunctival lesion and remains confined to the conjunctiva. Often arise from temporal conj.
Pterygium
- Findings
- tx
Triangular wedge of fibrovascular conjunctival tissue that starts medially on nasal conj and extends laterally onto cornea.
- artificial tears for dryness. Surgery considered for large lesions impacting visual acuity, but high risk of recurrence. Not to be confused with Pinguecula.
Different types of tumors
Basal cell/ squamous cell/ meibomian gland/ malignant melanoma
Dacryocystitis
accute inflamm of the lacrimal sac usually due to congenital or acquired obstruction of nasolacrimal system (supratemporal region)
Common in kids
F>M
Dacryocystitis
acute vs chronic
- Sx/sxs
- Causes
Acute- erythema, swelling, warmth, tenderness of the lacrimal duct and/or purulent discharge. Cause: alpha-hemolytic streptococci, S. epidermis, S. aureus
chronic-epiphora, mucopurulent drainage, +/- decreased visual acuity
cause: S. epidermidis, gram-neg bacilli
Dacryocystitis
Acute vs chronic
- tx
acute- abx, surgery (may be done in urgent cases), warm compress
Chronic- consider surgery for relief
Conjunctivitis
mode of transmission
most common eye disease
most common viral (bacterial, allergies also possible)
Mode of transmitiion- direct contact with fingers, towels, contaminated drops
Acute conjunctivitis
Discharge?
Vision?
Pain?
Cornea/pupil/IOP?
moderate to copious discharge (white-bacterial, clear-viral, clear/itchy-allergy)
no effect of vision
pain-mild
cornea- clear
injection-diffuse, more toward fornices
Pupil size/ light response/ IOP: normal
Viral conjunctivitis
- MC cause
- Sx/sxs
- tx
- MC cause- adenovirus
other causes: HSV
- bilateral, hyperimia of conjunctiva, watery discharge, foreign body sensation
- Cool compress/ NO patch
Bacterial conjunctivitis (pink eye)
- cause
- sx/sxs
- tx
- staph, MRSA, pseudomonas (contact lens), gonococcal (EMERGENCY), chlamydia (major cause of blindness)
- significant purulent drainage, mild discomfort, no blurring of vision, hyperimia
- abx, topical abx, very contagious.
Corneal abrasion
- Define
- Sx/sxs
- traumatic erosion of the corneal surface caused by trauma (fingernail, eyelash) or contact lens wear
- Mild-severe pain. tearing. photophobia. foreign body sensation. blepharospasm (eye twitch)
Corneal abrasion
- eval
- tx
- IVVEP.
Visual acuity, lid eversion, fluorescein staining are the MUSTS!
- Saline irrigation after the assesment (can use topical anesthetic but may not rx to avoid delayed healing)
abx ointment
daily f/u
Corneal ulcers
- Cause
- sx/sxs
- risk factors
- May result from inflamm or infxn (viral/bacterial)
- Pain, photophobia, tearing, no vision acuity changes unless central. Generally no change in visual acuity
- trauma, CONATCTS*, poor lid adiposition
Bacterial Keratitis
- MC pathogens
- Risk factors
- Findings
- Tx
- inflamm of the cornea caused by Pseudomonas, Staph (including MRSA), Streptococci
- contact lenses, corneal trauma, refractive surgery
- cornea is hazy, with an ulcer and adjacent stromal abscess. (angry eye)
- EMERGENT optho. Culture/gram stain.
Cataracts
- Define
- Risk factors
- lens opacification- MCC of blindness (reversible w/ surgery)
- Older age, trauma, systemic disease, smoking, UV exposure
Cataracts
- Clinical feature
- PE findings
- blurry vision, excess glare, fixed spots, color perception, decreased vision, BILATERAL and PAINLESS
- translucent white/yellow discoloration of the lens. Fundoscopic exam cataracts appears dark and red reflex absent
Cataracts
- tx
Important to prevent secondary glaucoma
Intracapsular and extracapsular extraction of cataract with lens replacement. Prognosis is great, post-op blled is less than 1%
Glaucoma
- Define/explain process
- Risk factors
- Increased IOP with optic nerve damage. Impediment of flow of aqueous humor through the trabecular meshwork and canal of Schlemm will increase pressure in ant chamber.
- 40 yrs and above. Fam hx of glaucoma or DM, common in African Americans, 2.5 million US population
Chronic glaucoma (aka open angle galucoma)
- Findings
- Ocular hypertension
- Tx
- Loss of peripheral vision “TUNNELING VISION” bilateral. Increased IOP. Increased cup:disc ratio.
- Elevated IOP without optic disc damage=ocular hypertension
- Refer to optho. Screen for hx of DM. Meds that decrease IOP by reducing aqueous humor production (i.e. beta-blockers) or meds that decrease IOP by increasing outflow (i.e Latanaprost)
Diabetic retinopathy
- % of population affected
- PE findings, which is worse?
- Tx
- 40% diagnosed diabetics. Leading cause of blindness in American adults
- non-proliferative (venous dilation, hemorrhages, microaneurysm, exudates, retinal edema) >>> proliferative (neovascularization, vitreous hemorrhage)
- Glu control, BP, lipid, renal fxn
laser photocoag (doesn’t always work)
Hypertensive retinopathy
- Risk factors
- PE findings
- What damage may be done?
- Significant in pts with rapid elevations of BP (malignant HTN-caused by organ damage or pre-eclampsia in pregnant females)
- atherosclerosis, tortuous/narrow retinal arterioles, flame hemorrhages(rupture on retinal nerve fiber), “cotton wool spots” (white patches on retina), exudates
- Can result in vasocontrict, ischemia, pigmented lesions. Permanent, choroidal, optic nerve damage
Macular degeneration
Risk factors
Older adults- leading cause of permanent visual loss.
Caucasion, F>M, family hx, smoking, +/- regular aspirin use. Toxic effect of meds (i.e. Chloroquine)
Macular degeneration
- Findings
- Wet vs dry
Age-related maculopathy that is characterized by retinal drusen extracellular deposits (seen on image as yellow deposits)
- Large associated with wet: neovascular/exudative, high severity
vs.
dry: atrophic/geographic, less severe than wet.
Both have gradual progressive bilateral visual loss
Macular degeneration
tx
None. Can attempt to stabilize/slow progression.
Diet: Vit C, E, zinc, copper… etc.
Intravitreol injection: VEGF inhibitors to stop production of new vessels
Papilledema
- Risk factors
- sx/sxs
Optic disc swelling, secondary to elevated intracranial pressure
Risk factors: malignant hypertension, hemorrhagic stroke, acute subdural hematoma, meningitis, tumors, etc..
- HA, N/V, pulsatile tinnitus, diplopia, “blind spots”
Papilledema
Findings: early, late, chronic
Early- disc hyperemia, subtle edema, small hemorrhages.
Late- obscuration of normal disk margins (elevated disk), venous congestion, paton line.
chronic- gray or pale disc, disc pseudodrusen
Papilledema
Frisen scale (0-5)
0- normal disc
1- C shaped halo of disc edema
2- circumferential halo of edema on optic disc
3- elevation of the optic disc with partial obscuration of one of more segments of blood v. at disc margin
4- almost complete obscuration of major blood v. on optic disc
5- partial or total obscuration of all blood v on surface of optic disc
Papilledema
- dx
- tx
- CT/MRI. MR venography. Optic coherence tomography. Fluorescein angiography. B-scan ultrasanography. Humphrey visual fields. Lumbar puncture- obtain opening pressure
- Treat underlying cause. HOB (head of bed) elevation greater than 30 degrees. Diuretics. Weight reduction. Pt requires close monitoring by ophtho.
What does lesions anterior to the optic chiasm affect?
Only one eye
What does lesions at optic chiasm affect?
Both eyes partially
What does lesions posterior to optic chiasm affect?
Corresponding defects in both visual fields
Nystagmus
- Define
- What are two types
rhythmic oscillation of the eyes
May be normal or indicate: central d/o or peripheral d/o
Types: Pendular- equal velocity both directions
jerk- slow phase of movement followed by a fast phase in oppositve direction (Gaze evoked or vestibular)
Gaze-evoked Nystagmus
When the pt attempts to gaze in one or more directions away from the primary position
single direction: early/residual ocular palsy
multidirectional- sedatives, central/cerebellar vestibular)
Vestibular Nystagmus
increase with gaze towards the fast phase and is accompanied by vertigo when caused by a lesion of peripheral vestibular apparatus.
unidirectional and horizontal associated with severe vertigo
Central Vestibular Nystagmus
bidirectional and purely horizontal, vertical, or rotary and accompanied by mild vertigo
Positional Nystagmus
elicited by changes in head position, can occur with peripheral (eval for hearing loss or tinnitus) or central lesions (eval for corticospinal tract or cranial nerve abnorms)
