Final Flashcards
What does normal visual acuity imply?
- ocular media are relatively clear 2. fovea centralis is intact. 3. CN II and visual pways are intact. 4. visual centers are intact
T or F: Normal visual acuity indicates that the eye is free of disease.
False - does NOT indicate lack of dz
What is the hardest letter to recognize?
B
What is the easiest letter to recognize?
L
What are the minimums for legal blindness?
< 20/200 in better eye OR a visual field that subtends an angle of <20 degrees
What chart do you use to indicate acuity for near vision?
Rosenbaum chart
What is known as “old vision”?
Presbyopia
What is presbyopia?
age-related loss of elasticity in lens => far-sightedness for near vision
Which msls are relaxed for far vision?
ciliary msls
When ciliary msls contract, what are they accomodating for?
near vision
What is known as the bending of light rays?
refraction (80% cornea, 20% lens)
What is emmetropia?
normal acuity (refraction of cornea and lens match the eye’s length)
What is it called when parallel light rays come to focus in front of the retina?
refractive myopia and near-sightedness. (refractive power of cornea/lens is too great)
What is it called when parallel light rays come to focus way in front of the retina?
axial myopia/high myopia and extreme near-sightedness (eyeball is too long for refractive power of eye)
What condition would have an increased chance of retinal detachment?
axial myopia/high myopia/extreme near-sightedness
What is it called when parallel light rays come to focus behind the retina?
refractive hyperopia and far-sightedness (refractive power of cornea/lens is too little)
What is it called when parallel light rays come to focus way behind the retina?
axial hyperopia and extreme far-sightedness (eyeball too short for refractive power of eye)
What has an increased chance of acute glaucoma?
axial hyperopia and extreme far-sightedness
What is defined as “unequal refraction in different meridians of the eyeball”?
astigmatism
What does an astigmatism cause difficulties in seeing?
fine detail
What is a “regular” astigmatism?
different degrees of refraction in vertical and horizontal planes => two focal points (right angle)
What is an “irregular” astigmatism?
different degrees of refraction in 2 or more meridians (NOT at right angle)
What are objective blind spots when assessing peripheral vision called?
negative defects
What are perceived blind spots called when assessing visual fields?
positive defects
What is blindness in one half of the visual field of one or both eyes called?
hemianopia
What is blindness in one quarter of the visual field of one or both eyes called?
quadrantanopia
What would a lesion of the midline optic chiasm cause?
bitemporal hemianopia
What would a lesion of the right optic radiation cause?
left homonymous hemianopia w/ macular sparing
What is “blind island”?
scotoma
What are “blind islands”?
scotomata
What is the space b/t the lens and retina filled with?
vitreous
What is it called when the vitreous thins w/ age and possibly separates from the back of the eye?
posterior Vitreous detachment (PVD)
What are floaters caused by?
tiny bits of vitreous gel or cells that cast shadows on the retina
When do flashes occur?
when vitreous tugs on sensitive retina tissue
What does PERRLA stand for?
- Pupils Equal in size and Round 2 pupils React to Light 3. pupils Accommodate to near vision
What is used to test the alignment of the eyes in a neutral position?
corneal reflection test
What does the cardinal fields of gaze assess?
- fixation of eyes 2. conjugate pursuit movements (“yoked” EOMs)
T/F: Ptosis is not always neurologic in origin.
TRUE
What is the most common cause of congenital ptosis?
localized myogenic dysgenesis (no abnormalities in pupil size)
What is Horner syndrome aka? Are there abnormalities in pupil size?
congenital CN III palsy; there are abnormalities in pupil size
What is the most common cause of acquired ptosis?
acquired aponeurotic ptosis
What are the 2 main findings for acquired aponeurotic ptosis
- lumps on eyelid (don’t squeeze) 2. No abnormalities in pupil size
Are there abnormalities in pupil size with acquired Horner syndrome?
Yes
What is acquired myogenic ptosis aka?
ocular myasthenia gravis
What is pupillary dyscoria?
abnormalities in the shape of the pupil
What would malignant melanoma of the iris and ciliary body cause?
acquired coloboma
What is an apparent absence or defect of tissue?
coloboma
What is synechia?
adhesion of the iris to the cornea or lens (type of acquired coloboma)
What is inequality in pupil size?
anisocoria
How are the pupillary reflexes affected in physiologic anisocoria?
pupillary reflexes are intact
What type of anisocoria is seen in 20% of the population?
physiologic
What are the 3 types of anisocoria?
- physiologic 2. pharmacologic 3. neurogenic
What is an example of neurogenic anisocoria that presents with a dilated pupil w/ sluggish and delayed rxns?
Right Adies tonic pupil/Adie’s pupillotonia
What is Argyll-Robertsons pupil a highly specific sign of?
neurosyphilis/tabes dorsalis
How does acute iritis present?
painful, aching, bloodshot, small pupil (unequal size)
What is the most important thing to do when pt has a bloodshot eye?
compare pupil size side-to-side
Urgency or emergency: anterior uveitis?
true medical urgency
How does acute glaucoma present?
very painful, bloodshot, large pupil
Does acute iritis or acute glaucoma look worse?
acute iritis looks worse/acute glaucoma has worse prognosis
Urgency or emergency: acute glaucoma?
true medical emergency
How do you differentiate acute glaucoma/iritis from conjunctivitis/pink eye?
conjunctivits is not an intra-ocular inflammation. Conjunctivitis does NOT cause changes in pupillary size or shape
What is a normal variant called for pupillary rxn to light?
Hippus
What presents with excessive constriction of the pupil and possibly the pupil won’t dilate in dark
miosis
What presents with excessive dilation of the pupil and possibly won’t constrict in bright light?
mydriasis
What is the accommodation triad?
- accomodative convergence 2. pupillary constriction 3. accommodation of lens for near vision
What an eye deviation that occurs when both eyes are open and uncovered?
tropia (detected by reflection test)
What is an eye deviation that occurs only when one eye is closed or covered?
phoria (not detected by reflection test)
What does the cover-uncover test detect?
Phoria
what are 2 normal variants for cardinal fields of gaze?
- hyper-dominant eye 2. physiologic end-point nystagmus of brief duration
When will “undershoot” or “overshoot” be seen?
Pts w/ cerebellar dz OR acute alcohol intoxication (aka homeboy is wasted)
What are jittery eye movements an early indication of?
MS
What is known as non-paralytic strabismus?
concomitant strabismus/constant tropia
T/F: degree of deviation between the eyes with constant tropia varies with position of gaze.
False - does not vary
What does concomitant strabismus imply?
- abnormality of msl origin or insertion 2. abnormality of msl length
What is seen with paralysis and/or restrictions to movement of EOMs?
non-concomitant strabismus/non-constant tropia
T/F: degree of deviation between the eyes with non-constant tropia varies with position of gaze.
True
What can cause restricted EOM movement?
- ophthalmic Graves dz (hyperthyroidism) 2. orbital fx
Non-concomitant/non-constant EOM palsy will have the worst deviation and double vision occuring when the pt looks in what direction?
In the direction of the weak msl
What palsy presents with ptosis and marked eye deviation?
CN III palsy/oculomotor
What palsy presents with pt unable to move eye downward?
CN IV palsy/trochlear
What palsy presents with eye deviated inward from neutral position?
CN VI palsy/abducens (impaired outward gaze)
Which palsy is the most common CN anomaly?
CN VI palsy/abducens