Midterm Exam Flashcards
How do you check the direct/consensual pupil reflex?
direct: shine light into eye for 2sec (5-6cm)
consensual: shine light into 1 eye while looking at the other for 2sec (5-6cm)
How do you check for an APD?
shine light into one eye for 3sec, rapidly move to other eye for 3sec and repeat
What is the clinical significance of an APD?
asymmetry in the afferent pathway
What is anisocoria? and when is it normal vs. abnormal?
Different pupil sizes. Normal = within 1mm (illumination level shouldn’t change amount)
Abnormal = more than 1mm
What is the pathway for the sympathetic pupil response?
mydriasis/dilation (iris dilator)
and anisocoria will be greater in dim illumination
What is the pathway for the parasympathetic pupil response?
miosis/pupil constriction (iris sphincter) and anisocoria will be greater in light illumination
What are the 3 ways to control amount of illumination?
height, width, and intensity of beam
What are the 2 most common illumination techniques?
wide beam and direct
How do you grade the bulbar conjunctiva?
0-4: 0=normal, 1=trace, 2=mild, 3=moderate, 4=severe
Which vessels are moveable with eyelid friction?
conjunctival vessels
what is the layer of vessels deep to the conjunctival vessels?
episcleral (do not move)
What is considered a ptosis?
if the palpebral fissure differs by more than 0.5mm
what is the normal position of the upper lid margin?
2mm below the upper limbus
what is the normal position of the lower lid margin?
about 1mm above the lower limbus
What is Munson’s sign?
a V-shaped dent of the lower lid produced by the conic cornea in downgaze (keratoconus)
What are the 3 most common TED lid signs?
Dalrymple’s sign, Von Graefe’s sign, and Stellwag’s sign
What is Dalrymple’s sign?
abnormally widened palpebral fissures, “pseudoptosis” (surprised look)
What is Von Graefe’s sign?
lid lag in down gaze, lag of upper eyelid in following the globe when patient looks down (sclera is continuously seen)
What is Stellwag’s sign?
infrequent or incomplete blinking
What is Gifford’s sign?
difficulty in everting upper lid
What is Vigouroux sign?
eyelid fullness or swelling (upper and/or lower)
What is Mobius sign?
poor convergence
What is Boston’s sign?
“jerky” lid lag
What is the best light source to evaluate pupils with?
transilluminator (direct, BIO, and slit lamp may also be used)
If you don’t have a slit lamp, what can you use to check gross angle assessment?
20D lens with a transilluminator or shadow technique
How do you grade the shadow technique?
4=wide open or no shadow, 3=25% of nasal iris in shadow, 2=30%, 1=40% and 0=50% or more
What is the most common cause of unilateral and bilateral exophthalmos?
thyroid eye disease (TED)
What do you use to measure exophthalmos?
Hertel exophthalmometer
What happens if the inner arcs are too far medial at orbital rim? or too far lateral?
too far medial = erroneously low
too far lateral = erroneously high
What difference between the exophthalmometer is considered abnormal?
difference of 2mm or more between the eyes (or an increase of 2mm or more over time)
What are the average readings for exophthalmometer for caucasian, african american and asian males?
21, 23, and 16mm
Name the 5 landmarks of the optic section
Pre corneal tear film, epithelium, bowman’s membrane, stroma, descemet’s membrane/endothelium
What are the “grainy” specs seen in the middle of the beam of an optic section?
keratocytes (corneal fibroblasts) - flattened cells that lie between and occasionally within the lamellae
What are the “layers” of the cornea seen in the optic section?
tears, epithelium, bowman’s layer, stroma, endothelium
Why is an optic section important?
it determines the depth and location of a defect (cornea or lens) - provides a 2D “slice” of tissue
What is the critical angle required for an accurate optic section of the cornea? Why is this angle “critical”?
60 degrees - if angle is too small the optic section collapses - limiting the information about the layers
What is the correct illumination technique (beam) used with the Van Herick?
Optic section at the corneal side of the limbus
According to VH measurements, which angle grade will “probably” close if dilated?
grades 1 and 2
Which VH grade strongly suggests the need for “gonioscopy” prior to dilation?
Grade 1
Where must you place the light for accurate angle estimations?
60 degrees
When is a wide beam used?
general observation and overview - lids, lashes, conjunctiva
What is the purpose of a parallelepiped beam?
provides a 3D examination of the cornea, conjunctiva, lens, iris - most effective at detecting tissue abnormalities
What is the set-up for a parallelepiped beam?
width (2-4mm), angle (20-45: depends on structure), med-high intensity, 10-16x
How does the angle change with more anterior structures?
the more anterior structure = wider angle (more posterior = smaller angle)
What is the set-up for an optic section?
very narrow beam (>1mm), tall (8mm), cornea = 60 degrees and lens = 20-30 degrees, med-high intensity, 16x
What happens if you are too far centrally doing a Van Herick?
the angle estimation will be artifically greater (will seem more open)
How do you grade a VH?
4=1:1 or higher, 3= 1/2-1/4:1, 2= 1/4:1 and 1= <1/4:1
When is a conical section used?
to examine the anterior chamber
What is the set-up for a conical section?
uses a parallelepiped beam but needs to be 1x3mm, angle is 30-45, max intensity, 25x, and need to dark adapt 30sec
What is indirect illumination used for?
produces a “softer” illumination to give better detection and definition - observation of cornea, lens and retina
What is the set-up for indirect illumination?
parallelepiped beam, 20-30 angle, med intensity, and 10-16x
What 2 other techniques does indirect utilize at the same time?
direct and retro-illumination
What is specular reflection used for?
corneal endothelium (only way to see this), anterior and posterior lens capsules
What is the optical principle that applies to specular reflection?
Snell’s law: light is reflected directly into only 1 ocular
What is the set-up for specular reflection?
parallelepiped beam, cornea = 20-45 and lens= 20-30, 16-25x, med-high illumination
When is sclerotic scatter used?
to view corneal edema
What is the set-up for sclerotic scatter?
parallelepiped beam, angle 45-60, tall height - look outside oculars with naked eye
How does sclerotic scatter work?
utilizes total internal reflection of the cornea
What is an epiblepharon?
extra horizontal row of skin across lid margin (common in children and asians)
What is xanthelasma?
infiltrates of the eyelid caused by lipid in the dermis - hyperlipidemia (small yellow/white bumps)
What is arcus?
a white ring around the peripheral cornea - cholesterol deposits
What is trichiasis?
eyelashes turned inwards - rub the cornea
What is madarosis?
decrease in number or complete loss of lashes - due to chronic lid disease (blepharitis)
What is trichotillomania?
condition where people pull out hair/lashes often when stressed and not aware of action (lashes are blunt/broken off)
What glands are infected/inflamed with an internal hordeolum or “stye”?
meibomian glands
What glands are infected/inflamed with an external hordeolum?
Zeiss and moll glands
What are reasons to evert the upper eyelid?
all new CL wearers, allergies, FB, lost CL, hordeolum, GPC, red eye cases
How do you grade blepharitis, MGD, and papillary conjunctivitis (bumps)?
grade 0=normal, 1=trace, 2=mild, 3=moderate, 4=severe
What is a loop of axenfeld?
posterior ciliary nerve piercing the sclera (ends before limbs)
What is the set-up to scan the conjunctiva (bulbar and palpebral)?
10x, wide diffuse beam, medium illumination, Polaroid filter on, 30 degrees
What are the different illumination techniques used to study the lens and anterior vitreous?
lens = direct (parallelepiped and optic section), specular, and retro-illumination
anterior vitreous = direct (parallelepiped) retro-illumination
What is the significant difference between performing an optic section of the lens vs. cornea?
cornea is at 60 degrees and lens is at 20-30 degrees (lens is more internal = smaller angle)
Why do more external structures need wider angles?
allows for viewing depth without the distraction from reflections from upper layers and can see behind the surface (direct/indirect/retro simultaneously)
What is the set-up to scan the iris?
16x, parallelepiped, med illumination, angle 20-30
What changes do you make after scanning the iris to scan the lens?
reduce vertical height to 5mm and reduce angle to 10-20 (un-dilated pupil= smaller angle)
What technique do you use to identify the anterior and posterior lens capsules?
specular reflection
What are the layers seen in the lens?
anterior capsule, cortex, adult nucleus, fetal nucleus, and embryonic nucleus
Which layer contains the Y sutures?
the fetal nucleus
What is the set-up to scan the anterior vitreous?
16-25x, thin parallelepiped beam, high illumination, 10-20 degrees
What causes a nevus of Ota?
unilateral proliferation of melanocytes following distribution of CN V1 and V2
What does a nevus of Ota look like?
facial and/or ocular slate-blue pigmentation = benign
What is Cogan’s senile plaque?
benign finding in elderly = thinned areas of sclera (bilateral - temporal and nasal)
What causes senile plaques?
horizontal recti muscles rubbing against sclera over time
What is conjunctivochalasis or redundant conjunctiva?
redundant or loose non-edematous conjunctiva which creates folds that billow over lid margin
Where is redundant conjunctiva usually located?
infra-temporal conjunctiva but can spread to superior bulbar
What is a pinguecula?
benign finding = yellow, slightly elevated bulbar conjunctiva thickening
What causes a pinguecula and where is it normally found?
nasal and/or temporal (IP zone) and results from a lifetime exposure to UV and elements
What is a pterygium?
thick, fleshy triangular mass of tissue on nasal conjunctiva
What are retention cysts?
common benign findings of interior palpebral conjunctiva - thin walled cysts with clear watery fluid (Krause glands)
What are concretions?
small, yellow-white hard bumps on palpebral conjunctiva (superior and inferior)
What causes concretions and when are they an issue?
idiopathic or result of chronic inflammation/dryness; if they become larger or calcify
What causes papillae?
vascular response - associated with an allergic reaction, bacterial infection, CL GPC
What do papillae look like?
reddish vascular tufts, varying in diameter - have a single vessel in center
What causes follicles?
normal in children, abnormal associated with viral infections (adenoviral, herpes simplex), drug toxicity (hypersensitivity)
What do follicles look like?
translucent elevations (pale mounds) of infiltrate of varying diameter - avascular centers
What is superficial punctate keratitis (SPK)?
a corneal surface disorder - breakdown and damage to epithelium
What are the symptoms of SPK?
dry, gritty, photophobia
what causes SPK?
dry eyes, CL, drug toxicity, trauma, blepharitis, conjunctivitis
What are sub-epithelial infiltrates (SEI)?
not benign - white blood cells have entered the cornea (detect with indirect)
What is limbal girdle of vogt?
chalky appearance and raised degeneration around limbus (no clear area between limbus and cornea –> arcus does)
What 2 types of scars need to be viewed with the slit lamp?
nebular and macular
what type of scar can be seen without the slit lamp?
leukoma
which type of scar has no effect on VA?
nebular
How do macular and leukoma scars affect vision?
macular = VA is effected leukoma = significantly reduced
Why would a cobalt blue filter be used?
aid NaFL assessment of cornea and conjunctiva - dry eye evals, GPC, RGP CL, iron deposits in cornea
What is a Hudson-Stahli line?
iron deposition line in corneal epithelium (benign = age-related) between lower pupil margin and inferior limbus
What is Fleischer’s ring?
iron deposits that form around the base of the “cone” in keratoconus
What are corneal striae (vogt’s striae)?
keratoconus patients or over-wearing CL - fine white vertical lines in stroma or descemet’s membrane
What is the best technique to view vogt’s striae?
parallelepiped beam and moderate magnification
What is PPM (persistent pupillary membrane)?
remnants of anterior portion of tunica vasculosa lentis
what are the 4 types of PPM?
iris to iris, iris to floating, iris to lens, iris to cornea
How common is PPM?
17-32% of population has PPM
What are the “cells” seen in the anterior chamber?
usually WBCs, sometimes RBCs or pigment cells
What is the direction of current in the anterior chamber?
up to warm lens and down to cold cornea
what is the “flare” seen in the anterior chamber?
fibrinous exudate
What are the symptoms of cells and flare?
variable pain, photophobia, red-eye, intraocular inflammation
What causes cells and flare in AC?
due to breakdown in blood aqueous barrier by inflammation (uveitis, iritis)
What is Tyndall phenomenon?
sub-mircoscopic particles become visible in bright beam of light against the dark background of the pupil
How do you grade cells?
0= 0 cells, trace = 1-5, 1+ = 6-15, 2+ = 16-25, 3+ = 26-50, 4+ = 50+
How do you grade flare?
0, trace = none, 1+ = faint, 2+ = moderate (iris detail +), 3+ = marked (iris hazy), 4+ = intense (fibrin/plastic aqueous)
What is a hyphema?
RBC or pigment cells pooled and settle inferiorly in AC
How do you know if the cells in a hyphema are RBCs or pigment cells?
use a red-free (green) filter = RBCs will disappear because they will absorb the green light –> then it is pigment
What are the 2 ways to examine the lens?
frontal view with retro-illumination (cataract extend relative to visual axis)
parallelepiped or optic section (cross-sectional)
What is a mittendorf’s dot?
normal - always nasal to visual axis: embryological remnant of hyloid artery on posterior surface of lens
what are episcleral stars?
small light brown or tan (despite iris color) dots on anterior capsule (single or multiple) = remnants of tunica vasculosa lentis
What are the 5 types of congenital cataracts?
anterior axial embryonic, anterior/posterior polar, sutural, pulverulent, and currulean
what are anterior axial embryonic cataracts?
(25% of population) opacities in a propeller shape anterior to embryonic nucleus (no VA reduction)
what are anterior and posterior polar cataracts?
opacity on the visual axis (reduction in VA depends on size) *need an optic section to know which layer it is on
what is a sutural cataract?
opacity is around the Y suture (rarely affects VA)
what is a pulverulent (dust-like) cataract?
ring/disc shaped opacities in embryonic nucleus
- retroilluminate when dilated, if cataract blocks orange glow, it will affect vision
- cause glare at night and not able to get perfect 20/20 vision
what is a currulean (blue dot) cataract?
small bluish punctate opacity of peripheral cortex (doesn’t affect VA)
What are the 6 types of age-related cataracts?
nuclear sclerosis (NS), cortical, posterior sub-capsular (PSC), traumatic, secondary, and posterior capsular opacification (PCO)
Where do the first changes of a nuclear cataract occur?
at embryonic nucleus - appears hazy and less distinct –> then begins to appear yellow
Why do patients with NS complain of reduced VA?
NS leads to a myopic shift in refractive error
How do you grade NS cataracts based on color?
trace = slight yellow, 1 = yellow, 2 = very yellow, 3 = yellow-orange, 4 = orange/brown
How do you grade NS cataracts based on BVA?
trace = 20/20, 1 = 20/25-30, 2 = 20/30-40, 3 = 20/50 - 60, 4 = 20/80 or worse
what are lens vacuoles?
as the lens ages - one of the early signs of change is in cortex with appearance of one or more shiny droplets of clear fluid
Where are lens vacuoles located?
under the capsule in mid-cortex or near adult nucleus
What can lens vacuoles lead to in cortical cataracts?
if fluid forces between individual lamellae in lens = lamellar separation and leads to dark areas in cortical cataract
What are cortical cataracts?
opacity is found in anterior, posterior or equatorial portion of cortex = spoke like appearance in periphery
How do you grade cortical cataracts?
on how many quadrants they are in (1-4) *must view as dilated pupil
What is the fastest growing age-related cataract?
posterior sub-capsular (PSC)
What is a PSC?
located in front of posterior capsule - appears granular or plaque like with specular reflection (starts in center)
How is VA affected with PSC?
opacity is on visual axis - decreased VA (near worse) with glare –> typically vision is most affected when pupil is miotic
What causes a PSC?
age-related, steroid therapy, diabetes
How do you grade of PSC?
based on density of amount seen in retro-illumination while pupil is dilated (1-4)
What is a traumatic cataract?
caused by direct penetrating injury, blunt force trauma = rosette cataract on visual axis
what causes a secondary cataract?
drug induced from steroids, systemic disease, chronic anterior uveitis
What is a posterior capsular opacification (PCO)?
proliferation of equatorial lens epithelial cells along posterior capsule surface after cataract surgery (appearance of soap bubbles or grapes) = need YAG
