OS 212 - Ophtha Flashcards
(234 cards)
1
Q
orbit shape
A
pear
2
Q
orbit volume in adults
A
30 cc
3
Q
barrier between eyelid and orbit
A
orbital septum
4
Q
bones forming roof of orbit
A
frontal, sphenoid (lesser wing)
5
Q
bones forming lateral wall of orbit
A
sphenoid (greater wing), zygomatic
6
Q
bones forming floor of orbit
A
maxillary, zygomatic, palatine
7
Q
bones forming medial wall of orbit
A
ethmoid, lacrimal, frontal, maxillary, sphenoid
8
Q
wall of the orbit comprised of the most bones
A
medial wall
9
Q
entry site of all nerves and blood vessels to the eye
A
orbital apex
10
Q
structures passing through lateral SOF
A
superior ophthalmic vein, lacrimal, frontal, trochlear nerves
11
Q
structures passing through medial SOF
A
superior and inferior oculomotor nerve, abduscens and nasociliary nerves
12
Q
structures passing through optic canal
A
optic nerve, ophthalmic artery
13
Q
supplies retina
A
central retinal artery
14
Q
supplies lacrimal gland
A
lacrimal artery
15
Q
supplies upper eyelid
A
lacrimal artery
16
Q
supplies ciliary body
A
long posterior ciliary arteries
17
Q
supplies sclera, episclera
A
anterior ciliary arteries
18
Q
supplies limbus
A
anterior ciliary arteries
19
Q
supplies conjunctiva
A
anterior ciliary arteries
20
Q
supplies choroid
A
short posterior ciliary arteries
21
Q
supplies eyelids
A
medial palpebral arteries
22
Q
drainage of the eye
A
superior and inferior ophthalmic veins
23
Q
drains into ophthalmic veins
A
vortex veins, anterior ciliary veins, central retinal vein
24
Q
analogue of nictitating membrane
A
semilunar fold of bulbar conjunctiva
25
location of accessory lacrimal glands
fibrous layer of conjunctival stroma
26
accessory lacrimal glands
glands of Krause and Wolfring
27
layer of the conjunctival stroma not present at birth
adenoid layer
28
source of conjunctival arteries
anterior ciliary and palpebral arteries
29
innervation of conjunctiva
CN V1
30
fibrous membrane covering globe from limbus to optic nerve
Tenon's capsule
31
parts of Tenon's capsule at limbus
conjunctiva, Tenon's capsule, episclera
32
suspensory ligament of Lockwood
IR + IO + Tenon's capsule
33
thinnest portion of sclera
at insertion of recti muscles, 0.3mm (half as thick)
34
contains BV that nourish sclera
episclera
35
T/F: The cornea is thicker at the periphery
T
36
T/F: The cornea is wider vertically
F, wider horizontally (11.75mm)
37
five layers of the cornea
epithelium, Bowman's membrane, stroma, Descemet's membrane, endothelium
38
comprises 90% of corneal thickness
stroma
39
modified corneal stroma
Bowman's membrane
40
basal lamina of corneal epithelium
Descemet's membrane
41
maintains corneal deturgescence
endothelium
42
effect of disruption of corneal endothelium
corneal edema
43
T/F: Corneal endothelium is highly mitotic
F, has minimal capacity for cell division
44
mechanism of corneal endothelial repair
hypertrophy and sliding, NO mitosis
45
innervation of cornea
CN V1
46
attributed to corneal transparency
deturgescence, uniform structure, avascularity
47
comprises uveal tract
iris, ciliary body, choroid
48
middle vascular layer of eye
uvea
49
characteristic of iris capillaries
non-fenestrated
50
controls amount of light entering eye
pupil (dilates and constricts accordingly)
51
responsible for pupillary constriction
parasympathetic CN III
52
innervation of iris
fibers of ciliary nerve
53
2 zones of ciliary body
pars plicata, pars plana
54
part of ciliary body with ciliary processes
pars plicata
55
produces aqueous humor
ciliary processes in pars plicata of ciliary body
56
types of fibers of ciliary muscles
longitudinal, circular, radial
57
internal portion of choroid
choriocapillaries
58
nourishes outer portion of retina
choroid/choriocapillaries
59
structure/shape of lens
biconvex, avascular
60
normal lens thickness
4 mm
61
normal lens diameter
9 mm
62
connects lens to ciliary body
zonules
63
liquid compartment anterior to lens
aqueous humor
64
liquid compartment posterior to lens
vitreous humor
65
T/F: Lens cortex is harder than the nucleus
F
66
T/F: Lamellar fibers of the lens are poorly mitotic, thus leading to poor eyesight in old age
F, its continuous production causes the lens to become larger and less elastic
67
water content of lens
65%
68
T/F: The lens can feel pain
F, there are no pain nerve fibers on the lens
69
volume of aqueous humor
230 uL
70
rate of aqueous humor production
2.5 uL/min (subject to diurnal variation)
71
aqueous humor pathway
ciliary processes -> posterior chamber -> pupil -> anterior chamber -> trabecular drainage -> Schlemm's canal -> venous system
72
main anatomic structures of anterior chamber angle
Schwalbe's line, trabecular meshwork, scleral spur
73
demarcated by Schwalbe's line
end of corneal endothelium
74
anterior extensions of retina
ora serrata
75
parts of retina without subretinal space
disc, ora serrata (other areas prone to retinal detachment)
76
10 layers of the retina
retinal pigment epithelium (inner layer of ciliary Bruch's membrane), photoreceptor layer, external limiting membrane, outer nuclear layer (photoreceptor bodies), outer plexiform layer (photoreceptors to bipolar and horizontal cells), inner nuclear layer (bipolar, amacrine, horizontal cell bodies), inner plexiform layer (amacrine and bipolar cells to ganglia), ganglion cell layer, nerve fiber layer, internal limiting membrane
77
T/F: Retina is thicker at the posterior pole than anterior (ora serrata)
T, 0.56mm thick posteriorly and 0.1 mm thick anteriorly
78
location of macula
center of posterior retina
79
location of fovea
center of macula
80
retinal avascular zone in fluoroscein angiography
foveal reflex
81
photoreceptors in foveola
cones only
82
blood supply of retina
outer 1/3 - choriocapillaries, inner 2/3 - central retinal artery
83
sole blood supply of fovea
choriocapillaries
84
T/F: The fovea is able to repair itself after macular detachment
F, damage is irreparable
85
characteristic of retinal blood vessels
non-fenestrated, forms inner BRB
86
location of outer BRB
level of RPE
87
location of macula with respect to OD
temporal
88
part of retina first hit by light
inner limiting membrane
89
comprises 2/3 eye volume and mass
vitreous humor
90
outer surface of vitreous
hyaloid membrane
91
attachment of vitreous base
pars plana, immediately behind ora serrata
92
T/F: Vitreous attachment to optic nerve and lens capsule persists throughout life
F, formed early in life but soon disappears
93
origin of recti muscles
annulus of Zinn
94
longest and thinnest EOM
SO
95
only EOM not originating from orbital apex
IO
96
spiral of Tillaux
connects recti insertions to sclera (MILS)
97
blood supply of EOM
branches of ophthalmic artery
98
additional blood supply to LR
branch of lacrimal artery
99
additional blood supply to IO
branch of infraorbital artery
100
hairless prominence between eyebrows
glabella
101
layers of the eyelid
skin, orbicularis oculi muscle, areolar tissue, tarsal plates, palpebral conjunctiva
102
main support of eyelid
tarsal plates
103
closes eyelid
orbicularis oculi (palpebral)
104
innervation of orbicularis oculi
CN VII
105
length of lid margin
25-30 mm
106
width of lid margin
2 mm
107
parts of anterior lid margin
eyelashes, glands of Zeis (modified sebaceous glands), glands of Moll (modified sweat glands)
108
contains meibomian glands
posterior lid margin
109
passage of tears for drainage
lacrimal punctum (medial end of posterior lid margin)
110
number of lacrimal punctum per eye
2 (superior and inferior)
111
opens upper eyelids
levator palpebrae superioris, Muller's muscle (superior tarsal)
112
opens lower eyelids
inferior rectus, inferior tarsal
113
innervation of lacrimal gland
lacrimal nerve (CN V1 -- sensory), great superficial petrosal nerve (secretory), sympathetic nerves
114
drains lacrimal gland
ophthalmic vein
115
tear drainage pathway
lacrimal gland -> lacrimal puncta -> canaliculi -> common canaliculus -> lacrimal sac -> nasolacrimal duct -> nasal meatus
116
number of axons in optic nerve trunk
1.2M from ganglia of retina
117
types of optic nerve fibers
80% visual, 20% pupillary
118
visual fibers vs. pupillary fibers
pupillary fibers bypass lateral geniculate body towards pretectal area
119
T/F: Ganglial cells are capable of regeneration
F, being part of CNS, they can't
120
color with shortest wavelength
violet (380 microns)
121
color with longest wavelength
red (760 microns)
122
visible spectrum
380-760 microns
123
change in speed of light from air to water (increasing refractive index)
slows down
124
direction of light deviation in a prism
towards base
125
structure of diverging lens
>< (-)
126
structure of converging lens
<> (+)
127
unit of measurement of lens power
diopter (D), 1/focal length
128
factors affecting lens power
lens curvature, difference in refractive indices
129
total converging power of human eye
60D - 40D cornea, 20D lens
130
parallel light rays dall into pinpoint focus on retina
emmetropia
131
types of ammetropia
myopia, hyperopia, astigmatism
132
focus point in myopia
in front of retina
133
focus point in hyperopia
behind retina
134
causes of myopia/hyperopia
axial (eyeball length), refractive (corneal curvature)
135
correction of myopia
divergent lenses (negative)
136
correction of hyperopia
convergent lenses (positive)
137
astigmatism
uneven curvature of cornea/lens at different meridians
138
correction of astigmatism
cylindrical lenses
139
types of astigmatism
simple (myopic/hyperopic), compound (myopic/hyperopic), mixed
140
physiologic changes in accommodation
pupils constrict, eyes converge, lenses thicken
141
presbyopia
loss of focusing/accommodating power in old age (>40 yo)
142
correction of presbyopia
convergent lenses (positive)
143
number of photoreceptors in mature retina
120M rods, 6M cones
144
senses perceived by retina
light, form, color
145
components of visual pigments
Vit A + opsin
146
components of rhodopsin
cis-retinal Vit A + opsin
147
mechanism of conversion of light to impulses
light -> rhodopsin cleavage -> hyperpolarzation (Ca permeability); energy released through cis->trans conversion of retinene
148
minimum visual angle of Snellen big "E"
5 minutes
149
minimum visual angle of arms of Snellen big "E"
1 minute
150
determinant of visual acuity
form sense
151
color blindness: 'prot(o)-'
red
152
color blindness: 'deuter(o)-'
green
153
color blindness: 'tri-'
blue
154
color blindness: '-anomaly'
deficiency in color
155
color blindness: '-anopia'
loss of color
156
cone monochromats
only one color
157
rod monochromats
achromats, totally color blind
158
pattern of inheritance of color blindness
sex-linked, recessive
159
monocular vs. binocular vision
monocular - complete decussation; binocular - partial decussation
160
visual relay pathway
retina -> CN II -> optic chiasm (partial decussation) -> optic tracts -> LGN -> optic radiations (temporal/parietal) -> strial cortex (occipital)
161
images received by occipital lobe
C/L images; (e.g. left lobe receives right hemi-field images)
162
decussating images at optic chiasm
images from temporal hemi-fields (images from nasal half of retina)
163
images relayed by optic tract
C/L images; (e.g. left tract relays right hemi-field images)
164
visual field defect: optic nerve
I/L anopia
165
visual field defect: optic chiasm
bitemporal hemianopia
166
visual field defect: optic tract
C/L homonymous hemianopia
167
visual field defect: temporal optic radiation
C/L superior homonymous hemianopia (pie in the sky)
168
visual field defect: parietal optic radiation
C/L inferior homonymous hemianopia (pie on the floor)
169
visual field defect: occipital lobe
C/L homonymous hemianopia
170
types of eye symptoms
abnormalities of vision, abnormalities of ocular appearance, abnormalities of ocular sensation
171
abnormalities of vision
vision loss, visual distortion, flashing/flickering lights, floaters, oscillopsia, diplopia
172
abnormalities of ocular appearance
red eye, color abnormalities, miosis, focal mass, proptosis, strabismus, abnormal size
173
abnormalities of ocular sensation
pain, irritation, headache
174
BOV algorithm
sudden/gradual? mild/severe?; sudden mild - suspect dry eye; sudden severe - suspect CRAO; gradual mild - suspect error of refraction; gradual severe - suspect cataract or glaucoma
175
DDx: BOV
refractive error, ptosis, ocular media disturbance, retinal dx, CN II dx, visual pathway abnormalities
176
DDx: glare/photophobia
corneal edema, cataracts; irritation, foreign bodies, acute inflammation, error of refraction, mydriasis, scratches on glasses, hazy ocular media
177
DDx: visual distortion
CSCR, ARMD; migraine, strong correction, macular and CN II lesions
178
DDx: flashing/flickering
retinal detachment, posterior vitreous detachment; retinal traction, posterior vitreous detachment, migrainous scintillations/aura
179
DDx: floaters
vitreous condensations; normal vitreous strands, pathologic pigments, blood, inflammatory cells
180
DDx: oscillopsia (shaking vision)
nystagmus; lid twitching (myokymia), nystagmus
181
DDx: diplopia
monocular (error of refraction, media abnormalities, corneal irregularities, lens dislocation)
182
DDx: red eye with swelling
preseptal cellulitis, orbital cellulitis, external hordeolum
183
DDx: red eye without swelling
conjunctivitis, iritis, acute glaucoma, scleritis, pterygium, subconjunctival hemorrhage
184
DDx: periocular pain
lid, tear sac, sinuses, temporal artery tenderness
185
DDx: retrobulbar pain
orbital inflammation, orbital myositis, optic neuritis
186
DDx: ocular pain
corneal abrasion, corneal foreign body, glaucoma, corneal ulcer, endophthalmitis
187
DDx: nonspecific pain
accommodation fatigue, binocular fusion, tension/fatigue referred discomfort
188
DDx: itching
allergic sensitivity
189
DDx: dryness
dry eye, mild corneal irritation
190
DDx: tearing
ocular surface irritation, (with edema) abnormal lacrimal drainage
191
DDx: watery secretion
allergy
192
DDx: mucoid discharge
allergy, viral conjunctivitis
193
DDx: ropy/stringy discharge
allergy
194
DDx: mucopurulent secretion
bacterial/viral conjunctivitis
195
DDx: copious purulent secretion
gonococcal conjunctivitis
196
DDx: bloody discharge
viral conjunctivitis, SJS
197
DDx: dried crusts on lashes
blepharitis
198
DDx: headache
errors of refraction, presbyopia, migraine, sinusitis, high and low BPs, intracranial pressure, closure glaucoma
199
DDx: headache + nausea + vomiting
increased intracranial pressure
200
DDx: U/L headache from I/L eye + nausea + vomiting
closure glaucoma
201
parts of basic eye exam
VA, gross (eye and adnexae, pupil), EOM, IOP, fundoscopy
202
methods of measuring decreased vision
move closer to 1 m -> finger counting -> hand movement -> light projection -> light perception -> NLP
203
parts of gross examination
eye position, eyelids and eyelashes, conjunctiva and sclera, cornea and iris, pupil
204
parts of pupul examination
size and shape, light reflex, swinging flashlight
205
normal pupil size
2-4mm
206
affected part if (-) consensual and direct pupillary responses
efferent arm of involved eye (given vision is normal)
207
affected part if (+) RAPD
optic nerve of dilating eye (consensual > direct response); I/L lesion
208
purpose of swinging flashlight test
r/o U/L CN II lesion or asymmetry
209
normal IOP
10-21 mmHg (with both eyes at least within 2 mmHg of each other)
210
c/i of tension tonometry
suspected globe perforation
211
used for indentation tonometry
Schiotz tonometer
212
cons of Schiotz tonometer
affected by scleral rigidity, patients must be supine
213
findings in tension tonometry
soft, hypotonic, firm
214
gold standard for IOP measurement
applanation tonometry
215
used for applanation tonometry
Goldman Applanation tonometer
216
c/i of applanation tonometry
patients with corneal abnormalities (e.g. scars)
217
cons of applanation tonometry
needs special equipment, needs ophthalmologist, affected by corneal thickness and irregular corneal curvatures
218
used for mass measurement of IOP
air puff noncontact tonometer
219
structures to observe in fundoscopy
ocular media (ROR), optic disc (ddb, CDR), retinal vasculature (AVR), retinal background (h/e, color) , macular area (foveal reflex, h/e)
220
normal CDR
< 0.5
221
cause of increased CDR
glaucoma -> death of ganglion cells
222
forms optic cup
aggregation of ganglion cells from retina
223
course of retinal BV temporally
arching
224
course of retinal BV nasally
radial
225
retinal structure with light reflex stripe
retinal arteries
226
normal AVR
2:3-4:5
227
DDx: Drusen lesions
ARMD
228
DDx: dot hemorrhages
diabetes
229
DDx: submacular hemorrhage
ARMD
230
DDx: hard exudates
HTN, DM, vHLD, radiation
231
DDx: soft exudates
HTN, DM, CTdx, HIV
232
DDx: boat hemorrhage
trauma, blood dyscrasia, sudden increase in IOP
233
DDx: flame hemorrhage
HTN, RVO, blood dyscrasia, trauma
234
DDx: vitreous hemorrhage
HTN, DM, trauma
