Optoprep/ODquestions Flashcards
What does virgin cytotoxic T cells divide into?
- effector T cells
- memory T cells
What recognizes the MHC complex (antibody + MHC)?
cytotoxic T cells and virgin helper T cells
cytotoxic T cells divide into effector and memory T cells
What’s the function of effector T cells?
promote mitosis of T and B cells to help combat pathogens
What’s the function of helper T cells?
help direct the immune system to the appropriate cells
What’s the function of killer T cells?
inject chemicals to cause death in the target cell
What are the functions of B cells
upon activation by effector helper T cells and interleukins, begin mitosis and differentiate into memory B cells and effector B cells
new memory B cells are stored for future encounters
What produces antibodies?
B cells - serve to inactive the offending agent
What’s the vertex distance equation?
Fc = Fs/1-dFs
Fc = dioptric power of the corneal plane
Fs = dioptric power of the spec plane
d = vertex distance in m
What’s weber’s Law?
K = delta I/I
K = Weber’s constant
I = difference in threshold
I = original stimulus intensity
Goldmann 3 mirror
Trapezoid 73 degrees = eval retinal equatorial region
bullet mirror 59 degrees = assess ora serrata
square mirror 67 degrees = anterior equatorial retina and the ora serrata
What’s the color of the following wavelengths?
Red
Orange
Yellow
Green
Blue
Violet
What is the avg cell density of the endothelium
3000
cellular density count below ____ cells/mm2 is associated with what risk?
1000
high risk for corneal endothelial decompensation
Vitrosin
unique collagen that is capable of binding large amts of water (up to 200x its weight)
- contains hydroxyproline (specific to collagen)
- originates from the neruoectoderm
Where are hemoglobin and albumin found?
proteins found in blood
creatine
used as an energy source primarily by our muscles
xanthophyll
yellow appearance in the macula
- combination of zeaxanthin and lutein
- decrease the formation of free radicals
- not made in our body which is why we advise pts with macular degeneration to take oral supplements (AREDS)
What’s the avg IOP?
15 mmHg (+/- 2.57mmHg)
normal fluctuation of IOP?
3-5mmHg
Which glands produce oil?
MG and zeiss
Which glands are apocrine (sweat) glands?
Moll
Which glands produce the aqueous layer of the tear film?
Krause and Wolfring
Describe a stage 3 macular hole
- FT macular hole (400um), smooth edge, small, surrounding, donut-shaped cuff of subretinal fluid
- yellow deposits at the base of the neuroretinal defect, along with perifoveal cystic changes
- operculum may be present but vitreofoveal separation has not occurred
A deficiency of which vitamin can lead to prolonged dark adaptation?
Vit A
- active form of Vit A is retinol which is important for the formation of rhodopsin
- rods most active in situations with dim illumination
Less rhodopsin means?
fewer rods being able to respond in low levels of light
- need Vit A for formation of rhodopsin
Neutral density filter equation
OD = log(1/T)
OD = optical density
T = transmission faction of the filter
Which CN innervates the follow EOMs?
SR
IR
MR
SO
IO
LR6SO4, everything else is innervated by CN3
The oculomotor nerve has 2 divisions
What does the super and inferior divisions innervate?
Superior = SR and Levator
Inferior = IR, IO, MR
The equation for total transmission of light
multiply the percentages of all the lens materials in which light passes through
What is the strongest predictor for diabetic maculopathy and PDR?
duration of diabetes
What’s optimal drop volume?
20uL
Rubeola
- measles
- seen in children btw the ages 5-15
- VERY contagious
- fever, bloodshot eyes, sore throat, coughing, maculopapular rash on the trunk, limbs, arms, face and neck
- koplik’s spot (white spots inside the mouth or buccal area), conjunctivitis
- self-limiting and tx is palliative in nature
- use ocular lubricants, vasoconstrictor drops, sunglasses
- there’s a vaccination for this
Parotiditis
infection or swelling of the salivary glands
- often seen in pts w/ mumps
- maculopapular rash
maculopapular rash
can be seen in a variety of viruses
What happens if a RBC is placed in 100% distilled water?
swells (cell contains higher concentration of solutes)
- distilled water is hypotonic to the cell
What if a RBC is placed in solution that contains higher concentration than the RBC?
cell shrinks and becomes crenated
What if the RBC and solution surrounding it has equal concentration?
isotonic (water will not leave or enter the cell)
Fluorescein angiography should be performed with caution when?
- Pt is taking B-blockers (in the case that the pt does have anaphylaxis, it is more difficult to manage if the pt is taking meds)
- Anaphylaxis
Visuoscopy is used to evaluate __
eccentric fixation
When is stereopsis present? when does it reach adult levels?
- present at 3-5 months
- adult-like levels at 5-7 years
non-granulomatous intraocular inflammation?
primarily what cells are present?
most common conditions that causes this?
WBC and protein
Idiopathic and ankylosing spondylitis (HLA-B27)
Most common cause of persistent decreased VA after a BRVO?
chronic macular edema
- neo, pre-retinal hemes or vit hemes, TRD can also develop
Sherrington’s law
when a muscle is stimulated to contract, its antagonist is inhibited
“SHER ONE EYE”
What happens if you see a break while neutralizing a lens?
that means that the lens possess astigmatism
with break = line appears to break at the same direction of rotation
against break = should exhibit 90 degrees away from with break
programmed cell death
apoptosis
premature death of living cells/tissues
necrosis
autolysis
destruction of a cell by means of its own enzymes.
- aka self digestion
Phagocytosis
- ex. macrophage, neutrophils, dendritic cells
- engulfs a particle forming and internal vesicle known as a phagosome
Prosopagnosia
- lack of ability to recognize faces
Which part of the brain plays a role in facial recognition
IT cortex
Achromatopsia
inability to identify colors
color agnosia
a type of visual agnosia in which a person has difficulty associating colors with specific objects
Akinetopsia
which part of the brain is damaged?
cannot see mvmt in VF due to MT cortex (important for processing motion stimuli)
What medication is used to treat bronchospasm associated with COPD
Salmeterol (Serevent) = long acting beta agonist
should not be used in acute attacks!
Which medications are used for acute asthma attacks and COPD and emphysema?
Albuterol (Ventolin) and Pirbuterol (Maxair)
which medication is used for chronic asthma?
- montelukast (Singulair)
- used in chronic asthma prevention and maintenance
What is the 1st and 2nd most common cause of intermediate uveitis?
- idiopathic
- sarcoid
Is lime/plaster acid or alkali
alkali
Nucleobases
- pyrimidine
- cytosine
- thymine (DNA)
- uracil (RNA)
- guanine
- adenine
- all composed of purine or pyrimidine ring structures
cytidine and deoxyguanosine
- nucleosides which are composed of nucleobase joined with a sugar (ribose or deoxyribose)
Adenosine monophosphate
- nucleotide, an nucleoside linked with one or multiple phosphate
What is a nucleotide composed of?
nucelobase, sugar (ribose or deoxyribose), phosphate
- ex. ATP, NAD+, coenzyme A, cAMP
Short-term escape and long-term drift are usually associated with which medication?
timolol
- short term escape = occurs within the first few days
- long term drift = within months of initiating tx
oral antivirals should be initiated when after an onset of an acute HZ
72 hrs
Doses of antivirals meds?
Oral acyclovir: 800 mg 5x/day 7-10 days
Famciclovir: 500 mg TID
Valacyclovir: 500mg TID
HSV vs HZV
HSV = has terminal end bulbs, stain centrally, dendrites larger than zoster lesions, improves with topical antiviral
HZV = only stain w/ rose bengal, small lesions, may not improve with antiviral meds
overall diameter of the posterior surface of the cornea
11.7, spherical
anterior cornea vertical and horizonal measurements
vertical 10.6, horizontal 11.7
elliptical
spatial summation of the scotopic system
high sensitivity and poor resolution
Chloramphenicol side effects
- binds to 50S subunit
- chloramphenicol very lipid- soluble and easily crosses the BBB
- bone marrow depression, aplastic anemia, gray baby syndrome, optic neuropahty, teratogenesis, and enterocolitis
- useful for staphylococcal brain abscesses and certain types of meningitis
Tamoxifen
- tx breast cancer
- crystallin deposits on the plexiform and NFL around the paramacular region
- corneal deposits, CME, grey lesions in theRPE, retinal heme, optic disc edema
- ocular toxicity associated with high dose 120 mg daily
- standard daily dose is 20 mg
- should have a baseline and yearly dilated eye examination with OCT of the macula
What type of fungi is used to culture fungi?
sabouraud’s agar
Metformin
- biguanide
- increase insulin sensitivity, molecular target is the AMP- dependent protein kinase (AMPPK)
- activates AMPPK to block break down of fatty acids and inhibit hepatic gluconeogenesis and glycogenolysis
Biguanides
Metformin (Glucophage, fortamet, glumetza, Riomet)
A cls that is rotated from its proper axis shows how much of the original power in the OR
10 degrees
15 degrees
3 degrees
A cls rotated 10 deg away from proper axis will result in a manifestation of astig that is 1/3 of its original power in the OR
- 10 degree = 1/3 the original power
- 15 degrees = 1/2 the original power
- 30 degrees = full amt of cyl power
Convert logMAR to snellen
20 x 10^(logmar)
Pretibila myedema is associated with which condition?
graves dz and hashimotos thyroiditis
- waxy, discolored, raised plaques of non-pitting edema of the skin
most common type of anterior scleritis
diffuse scleritis
What medication causes bulls eye maculopathy
chloroquine
Risk for toxicity is less with ___ for hydroxychloroquine
<5.0 mg/kg of body weight per day
Risk for toxicity is less than ___ chloroquine
<2.3 mg/kg body weight/day
What other ocular testing should you do for pt taking chloroquine
- color vision
- amsler grid
- OCT mac***
Where is oxytocin and vasopressin (ADH) stored? Where is it made?
stored in the posterior lobe of the pituitary gland, made by the hypothalamus
What part of the vitreous is cloquet’s canal located?
primary vitreous
FDA classifies non-silicone hydrogel soft lens into 4 groups
Group 1: cls posess low water content, non-ionic
Group 2: high water content non-ionic
Group 3 low water content, ionic
Group 4 high water content, ionic
lens made from ionic compound tend to attract more protein, so a person who attracts more proteins should be fit in lenses in category 1
RGP lens guidelines
competitive inhibitor on a lineweaver-burk plot of an enzyme
increase slope
non-competitive inhibitor on a lineweaver-burk plot of an enzyme
decrease slope
digoxin
- cardiac glycoside, prescribed for hearth failure and arrhthmias
- xanthopsia (yellow/green tint to vision)
- blurry vision and halos around bright lights
What does the schirmer tear strip test for?
tear production, specifically the aqueous portion
decompression sickness aka “the bends” while diving is caused by what?
rapid mvmt of nitrogen from tissues into the blood stream
Pt with advanced glaucoma should perform which VF test?
10-2
which anti-muscarinic meds are contraindicated in narrow angle?
- treat asthma and COPD
- Ipratropium (atrovent) and tiotropium (spirvia)
treatment for CMV retinitis
ganciclovir (Cytovene) implant
- blurred vision, floater, scotoma ine one eye, mid peripheral heme “brushfire”
- AIDS
scopolamine patch
- induce mydriasis and reduce accommodation making it harder to read
Mooren’s lightening streaks
brief vertical light flashes typically seen in temporal VF at night that are elicited by acceleration of the head (vitreotraction)
most allergic reaction to anesthetic are due to
ester group
amide group
ester
bile is important for
break down of fat
Ester vs amide anesthetics
amide has 2 “i” in the generic name of the drug
ester has 1 “i”
contrast sensitivity function of an 80 yo will shift the curve to the __
left
What topical medications can cause hypoesthesia w/ chronic use?
NSAID
B-blockers
anesthetics
CAIs
cls wear can also cause hypoesthesia
Meissner’s corpuscle
found more superficially and detect low-frequency vibrations
end bulbs of krause
react to temps <20 deg C
ruffini endings
respond to constant pressure and touch as well as temps above 45 deg C
Pacinian corpuscles
located deeper in the dermis and sensitive to rapid presure changes related to vibration and touch
- also found in some internal organs that lie close to freely-movable joints
Chlorpromazine and thioridazine s/e
pigmentary changes/clumping in mid-periphery and posterior pole, focal/diffuse atrophy w/ chlorpromazine of the RPE and choriocapillaris
chloroquine and hydroxychloroquine
bulls eye maculopathy, pigment in the macula,
Canthaxanthin
crystallin retinopathy
which condition is assocaited with a chancre (painless ulcer)
syphilis found on the penis or vulva
inverse square law - amt of lumens falling on the surface decreases with square of the distance
E=I/d(squared)
E= illumination falling onto the surface
I = intensity of point source
d = distance between the surface and the light source
whats the minimum thickness of RGP?
0.12mm
Synergism
response elicited by combing drugs is greater than the response of the individual drug
Additive effect
response elicited by combing drugs equal to the combined response of an individual drug
Potentiation
drug which has no principal effect enhances the effect of a 2nd drug (ex. amoxicillin w/ clavulanate)
Antagonism
A drug inhibiting the effect of another drug
how often do we blink?
12-15 times a min
What eye drop is used to distinguish episcleritis vs scleritis?
phenylephrine, neosynephrine
how much ganglion cell axons are lost per year?
5,000
but more rapid with certain ocular dz like optic neuropathy.
Reye’s syndrome
-linked with aspirin
- most destructive to the brain and liver
- always associated with previous viral infection
whats the equation for center thickness?
ct = 0.023 x cls power +0.20
as radius of curvature is thickened ct increases
What’s the BP for the following?
Normal
elevated
stage 1 HTN
stage 2 HTN
Hypertensive crisis
ADH
- distal tubules become more permeable to water
- stored in the posterior pituitary
- decr amt of fluid to be excreted as urine
volume of the vitreous
4ml
CME affects which retinal layers?
INL and OPL
- break down of capillary beds causing leakage of fluid
what’s the peak absorbency for the scotopic system/rhodopsin
507nm
increasing water of a soft (non-silicone) hydrogel cls will cause what?
increase dry eye symptoms
increasing water for silicone hydrogel will cause what?
decrease oxygen permeability
route of depolarization of the heart
SA node > AV node > Bundle of HIS > purkinje fibers
pacemaker of the heart
SA node
PMD vs KCN
- reduced BCVA w/ glasses is lost typically younger in pts with KCN compared to PMD
- protrusion of KCN occurs centrally or inf to the visual axis
- protrusion of PMD occurs above the area of thinning
- CT is reduced in KCN and normal in PMD
- fleischer’s ring, apical corneal scarring, munson sign are you usually found in mod to severe stages of KCN
What secretes insulin?
beta cells of pancreas in response to elevated glucose
What are the target sites for insulin?
liver, adipose tissue, muscle cells
glucokinase and glycogen
activated by the liver which results in increase in uptake of glucose and synthesis of glycogen
what breaks down glycogen?
glycogen phosphorylase
lipoprotein
activated in adipose tissue to increase synthesis of triglycerides
which antibody can cross the placenta?
IgG
What antibody is first to respond during an immune response?
IgM
What is the basic unit used to measure retinal illumination?
trolands
T=LA
T = troland
L = luminance of the viewed surface
A = area of the pupil
what’s the unit for illuminance?
lux
whats the unit for luminous power?
lumens
what unit is used to quantify luminance?
foot-lamberts
Dalen-fuchs nodules are associated with which condition?
vogt koyanagi- Harada syndrome
loop diuretic
furosemide
- inhibit electrolyte reabsorption at the loop of henle
hydrochlorothiazide
- thiazide diuretic
- inhibit Na+ and cl- reabsorption in the distal renal tubule
spironolactone
K+ sparing diuretic
- inhibit Na+ excretion while sparing K
acetazolamide
- CAI
- inhibits CAI
mannitol
osmotic diuretic
inhibits Na+ and water reabsorption
what’s the minimum thickness for residual corneal bed?
250um
hypothyroidism
- elevated levels of THS, low T4
what do these marking mean on a frame?
Z87-2
+
V
S
Z87-2 = successfully met the requirements for high-impact and high mass velocity
+ = passed high impact test
V = safety lens is photochromic
S = special purpose (ex. didymium lens worn by glass-blowers)
during saccadic mvmts why does the background not appear blurred as its moves across the retina?
selective suppression of the magno pathway
magno pathway
where pathway
- responds to quickly moving objects and high temporal frequencies = both occur in the background during a saccade
Ependymal cells
found lining cavities of the CNS as well as walls of the ventricle in the brain
- these cells form the epithelium of the choroida plexus which secretes cerebrospinal fluid
oligodendrocytes
non-neuronal cells of CNS and serve to coat axons in myelin sheath, which greatly increases the speed of conduction
wraps alot of axons at the same time
schwann cells insulate one to one cellular axons of the PNS