Reading assignment information-Chapter 7 The EYE Flashcards
What nerve is considered the “work horse” of the eye?
CN 3 (oculomotor)
What muscles are NOT innervated by CN3?
LR6SO4: Lateral rectus (CN 6) and Superior Oblique (CN4)
What are the 3 parts of the near reflex?
Accommodation
Convergence
Pupillary Constriction
What is the direct effect?
The constriction of the pupil of the eye on which the light is shined
What is the consensual effect?
The simultaneous constriction of the opposite pupil
Define accommodation
near focusing of the eye by increasing the power of the lens by contraction of the ciliary muscle innervated by CN3
What side of the eye is the optic disc located in?
the nasal side
What landmarks can you use to find the optic disc?
The anastomosis of the vessels will point towards the optic disk
What is the normal cup to disc ratio?
the cup should be 30% the size of the disc diameter
What are the major symptoms of eye disease?
Loss of vision Eye pain Diplopia Tearing and dryness Discharge Redness
What 2 questions must you ask when a pt c/o loss of vision?
Did the loss of vision occur suddenly?
Is the eye painful?
What questions must you ask if the pt states they have eye pain?
describe the pain? did it come on suddenly? Photophobia? Pain when you blink? FB sensation? H/A? Pain w/ movement? Pain over brow on same side? contact lenses?
What is the most common condition of dry eye?
inadequate amount of the water layer of tears-keratoconjunctivits sicca “dry eye syndrome”
What types of eye discharge exist? And what do they mean?
Watery/mucoid=viral or allergic
Purulent=bacterial infection
What does the physical exam of the eye include?
Visual acuity Visual fields Ocular movements External and internal eye structure Ophthalmoscopic exam
for VA: the first number on the chart is the distance at which ________ reads the chart; and the second number is the distance at which ________ reads the chart.
1st number : the distance at which the PATIENT reads the chart.
2nd number : the distance at which the person with normal vision can read the same line of the chart.
abbrev: OD
R eye
abbrev: OS
L eye
abbrev: OU
both eyes
How might you evaluate a patient who cannot read any line of print on the charts?
Finger counting ability
How might you evaluate a patient who cannot see well enough finger counting?
ability to see light
define scotoma?
An area of depressed vision
What is the physiological scotoma?
The “blind spot” located approx 15 to 20 degrees temporal to central fixation-it corresponds with the optic nerve head.
define hemianospia?
absence of half of the visual field
What is bitemporal hemianopsia? What is it a sign of?
a defect in both temporal fields. Results form lesion involving the optic nerve at the level of the optic chasm-often the result of pituitary tumor.
What is the most common type of visual field loss?
Homonymous hemianopsia-occurs frequently in stroke pts
What is assessed when testing ocular movement?
Eye alignment (light reflection) Cover test (for strabismus) 6 cardinal positions of gaze (EOM's) Pupillary light reflex Near reflex
In Marcus Gunn or RAPD phenomenon what is the most extreme example?
When the light is shone in the blind eye, there is neither a direct or consensual response. When the light is moved to the other eye, there is both direct and consensual response (this is bc both afferent and efferent pathways are normal. When the light is swung back to the blind eye, no impasse are received by the retina (afferent), and the pupil of the blind eye no longer remains constricted; it therefore dilates.
When the patient looks far to near what should occur?
The eyes should converge and the pupils should constrict.
What do we examine on External and internal eye structure inspection?
Orbits and eyelashes Lacrimal apparatus Conjunctiva Sclera Cornea Pupils Iris Anterior chamber Lens
What sings should be watched for when inspecting the eyelid?
drooping infection erythema swelling crusting masses other abnormalities
Define ptosis (aka blepharoptosis)
drooping of the eyelid
Define Kearns-Sayre syndrome
Chronic progressive external ophthalmoplegia-slow progressive symmetric ptosis and symmetric external ophthalmoplegia caused by an autosomal-dominant condition
Define Lagophthalmos
Inability to close the eyelids completely.-seen in thyroid dz
entropion
a turning in of the eyelid
ectropion
a turning out of the eyelid
What is the most common type of malignancy associated with cutaneous horn?
Squamous cell carcinoma is most common type of malignancy at the base of the horn
Define Sturge-Weber syndrome
Congenital condition recognizable by a characteristic port wine stand on one side of the face.
Chalazion
meibomian gland obstruction. Tx with warm compresses
What is indicated by orbital discoloration of “raccoon eyes”?
basilar skull fracture
Xanthelasma
yellowish plaques on the periorbital skin
Stye (acute external hordeolum)
localized abscess caused by a staph infection.
Characteristics that suggest malignant tumors of the eyelid?
Talangectasia
Alteration of normal acrhitecture (loss of eyelashes)
non-painful/non-tender
Irregular pigmentary changes
What is the most common occular manifestation of AIDS?
Lesions of Karposi’s sarcoma
Dacrocystitis
inflammation of lower lacrimal passages
What is the mc of all eye diseases in the western hemisphere?
Conjunctivitis
What sings should be evaluated for in inspection of the conjunctiva?
Pallor Unusual pigmentation Swelling masses hemorrhage
What is the most frequent type of conjunctivitis?
Bacterial
What is acute hemorrhagic conjunctivitis caused by?
ocular infection of enterovirus, pneococcus, H flu.
Giant papillary conjunctivitis occurs mostly in people who ____?
Are soft contact lens wearers.
Pinguecula
whitish yellow triangular nodular growth on the bulbar conjunctiva adjacent to the cornea (does not cross the cornea).
Pterygium
More vascular on the bulbar conjunctiva extends beyond the corneal scleral junction to the cornea.
What is evaluated for when examining the sclera?
nodules
hyperemia
discoloration
Jaundice (aka Icterus)
abnormal yellowing of the sclera
episcleritis
benign, usual painless, bilateral, recurring disorder. Non-infectious inflammation
Scleritis
painful, often bilateral, recurrent (less common than episcleritis), effects older groups, inflammation of sclera w/ involvement of cornea and uveal tract.
scleromalacia perforans
uncommon, painless, scleral condition-nectrozing scleritis seen in long standing RA pts
What should be evaluated for in inspected of the cornea?
should be clear, without opacities, cloudiness, or ulcerations
arcus senilis
whitish ring at the perimeter of the cornea-mc in pts >40yo.
What is an abnormal golden to greenish-brown ring near the limbus indicative of?
Kayser-Fleischer ring-specific sign of Wilson’s disease.
What is evaluated in inspection of the pupils?
normal = PERRLA
anisocoria
normal variation in about 5% of people where pupillary size is not equal
midriasis
pupillary enlargement
miosis
pupillary constriction
Argyll Robertson pupill
pupil constricted 1 to 2 mm that reacts to accommodation but is nonreactive to light (assoc w/ neurosyphilis)
Horner’s syndrome
sympathetic paralysis of the ey caused by interruption of cervical sympathetic chain. (miosis, ptosis, anhydrosis also present).
Adie’s tonic pupil
a pupil dilated 2 to 6mm that constricts little in response to light and accomodation
Inspection of the iris includes
shape, color, presence of nodules, vascularity
Iris colombana
a notch or gap in the iris
Inspection of the anterior chamber
Fluid composition (should be clear), depth of the anterior chamber
Blood in the anterior chamber is called?
hyphema
Pus in the anterior chamber is called?
hypopyon
The presence of a shallow anterior chamber predisposes a pt for?
narrow-angle glaucoma
How do you inspect the lens?
oblique lighting. looking for opacity of the lens
cataract
any opacification of the lens that causes reduced visual acuity
What is the proper way to hold the ophthalmoscope when examining the patients R eye?
- Hold the opthalmoscope with your right hand in front of your right eye.
- Ask pt to look straight ahead and focus on a distant object.
- Start with lens diopter set to 0 finger near the diopter
What is evaluated in Ophtlamoscopic exam?
Optic disc
Retinal vessels
Macula
Retinal lesions
What is a normal cup to disc ratio?
0.1 to 0.5
what should you evaluate the pt for if there is asymmetry to the physiologic cup?
Early glaucoma
What should be evaluated for when inspecting the optic disc?
Margins, color, and cup-disc ratio
What is indicated by “copper wiring” on inspection of the retinal vessels?
Vessels that are thickened and sclerotic
What causes AV nicking?
HTN -the arteriole and venues share a common sheath and the arteriole walls are thicker. This causes the venule wall to collapse when the pressure in the arterioles is higher.
What are you seeing when you ask the pt to look directly towards the light of your ophthalmoscope during exam?
Macula and fovea.
What are red lesions on the retina indicative of?
Hemorrhages
What are black lesions on the retina indicative of?
retinitis pigmentosa
What are white lesions on the retina indicative of?
Cotton-wool spots (if soft) or drusen (if dense).
hyperopia
farsightedness-light falls posterior to the retina
Myopia
Nearsightendness-light falls in from of the retina
astigmatism
light is not uniformly focused in all directions. astigmatism is commonly a result of a non-spherical cornea
presbyopia
Near vision decreases after the age of 40
What is the most common cause of blindness?
Cataracts
What is the leading cause of blindness in americans aged 20-75 yo?
Diabetic retinopathy
What is the first stage of diabetic retinopathy?
non-proliferative/ background retinopathy-Microaneurysms occur
What is the characteristic of proliferative diabetic retinopathy?
neovascularization. This causes pre-retinal hemorrhages and leads to boat-shaped hemorrhages. Further pulling on the retina can cause retinal tears and detachments.
What is the new tx paradigm for patients with neovascularization?
anti-VEGF agents-slows vision loss and maintains current visual acuity. Offers the potential of improving and even restoring functional vision.
What may be seen on ophthalmoscopic exam of a pt with HTN?
irregularities of arteriolar size
tortuosity of the retinal arteries
retinal edema
changes in the arteriovenous crossings.
What progressive changes can be seen on exam of pt with HTN?
arteriolar narrowing w/ increase areas of retinal ischemia evident by the development of cotton-wool exudates, hemorrhages, retinal edema and papilledema.
papilledema?
swelling of the optic disc
What is the common cause of cerebral retinal artery occlusion?
embolus from the heart or a larger artery. - results in a sudden painless loss of vision in 1 eye.
What is a “cherry red spot” a sign of?
central retinal artery occlusion
What are the signs of central retinal artery occlusion?
painless loss of vision in 1 eye
Pupillary direct light reflex is lose
venous pulsations are absent
cherry red spot at macula
What disorder has been described as a “pizza thrown against a wall?”
The fundus in a central retinal vein occlusion
What is the presentation of a pt with a central retinal vein occlusion?
Painless loss of vision in 1 eye.
venous dilation and tortuosity at the fundus
blurred optic disc and margins caused by edema
flame-shaped hemorrhages
cotton-wool spots
large hemorrhage at the macula
What is the most common malignant tumor of the sensory retina?
Retinoblastoma
What is the most common fundus tumor?
Choroidal nevus
What are floaters and flashes of light a warning sign of?
retinal tear/detachment
