Definitions Flashcards
ATR - against the rule
flatter in the vertical; steeper in horizontal (180); young and old
WTR - w/ the rule
steeper in the vertical; flatter in the horizontal; normal age population
amyloids
misfolded proteins
scleroderma
hardening of the dermis
posterior embryotoxon
Posterior embryotoxon presents as a thin, greyish-white, arcuate shaped ridge that runs adjacent to and parallels the limbus at the inner surface of the cornea. Axenfeld-Rieger anomaly occurs in association w/ posterior embryotoxon. http://www.ijo.in/articles/2011/59/4/images/IndianJOphthalmol_2011_59_4_312_82003_f1.jpg
anterior synechia
abnormal adherence of iris to corneal endothelium.
posterior synechiae
abnormal adherence of anterior surface of lens to iris
persistent pupillary membranes
remnant of the fetal iris membrane presenting as thin strands crossing the pupil
What does the QRS complex represent?
depolarization of left and right ventricles
What does the T wave represent?
ventricular repolarization, relaxation of the ventricles
index of refraction (n) of crown glass
1.52
Side walls of cells (epithelium/NPEC) are connected by ___________.
desmosomes
Which structures of the brain are a part of the limbic system and is involved in emotions?
amygdala, hippocampus, regions of the septal area, and limbal cortex
What is included in the limbal cortex?
hypothalamus, the cingulate gyrus, and the fornix
Where do the optic tracts of the eye terminate?
lateral geniculate nuclei (LGN) located in the thalamus
Where does information pass after the LGN?
primary visual cortex
Pulmonary vein-> left atrium-> mitral valve-> left ventricle-> semilunar valves-> aorta
Oxygenated blood is transported via the pulmonary veins to the left atrium. Blood then passes through the mitral valve to the left ventricle. Upon contraction of the left ventricle, blood is pushed through the left semilunar valve to the aorta where it then travels through arteries, arterioles, and capillaries for distribution throughout the body.
Excessive pantotilt causes…
increased (+/-) sphere power and induced cylinder axis 180 of the same power (+/-) as the sphere. A plus sphere will mean a (+) cyl is induced!
When you have a +2º pantoscopic tilt you have a ________ change in height.
-1mm height; also by increasing tilt, you are increases the field of view through the reading add
-2º pantoscopic tilt = _____ change in height.
+1mm height
horizontal prism w/ same base are _______
added together; i.e. BO + BO
vertical prisms w/ opposite bases are _______
added together; i.e. BU + BD; same side vertical prisms are subtracted from each other!
What is the ANSI prism tolerance?
Horizontal 2/3 PD (0.66PD); vertical 1/3 PD (0.33PD)
Your patient has an imbalance > 1.50 PD. You want to give him slab-off w/ a BU prism (correct tx), which lens do you place the slab off on?
The most minus lens because you are adding BU. You will always under prescribe the prism if needing to choose. The lower cost and quicker processing option is a reverse slab off, which you would place on the least minus lens(?)
What kind of lens does a Fresnel prism simulate?
reverse slab off lens
Define aniseikonia
A relative difference in size and/or shape of the ocular images. Pt will experience asthenopia, headaches, photophobia
Axial ametropia.. fit w/ ______
spectacles
Refractive ametropia (Ks are different)… fit w/ ______.
contact lenses
Flatten/Steepening by 1.00 means +/- 1.00D from the BC
i.e. 45.25D that is too steep by 1.00D. Flatten by 1.00 –> 44.25D, FAP, creates a minus tear film, so you have to add PLUS to the Rx (changing -3.75 to -2.75D)
prostaglandins decrease IOP by _________.
Increase uveoscleral outflow. decrease IOP by 33% on average (20-40%).
Which topical IOP meds decrease aqueous secretion?
ABCs!!!!!
alpha-agonists (apraclonidine, brimonidine)
beta-blockers (timolol)
carbonic anhydrase inhibitors (dorzolamide)
define cicatricial
scar/scarring related
Stocker line
deposition of iron, corneal epithelium, at the leading edge of pterygium
Hudson-Stahli line
iron, middle and lower third of cornea
Fleischer ring
iron, base of cone in keratoconus
What is the average size diameter of the iris?
12mm; iris is an extension of the anterior portion of pars plicata, the transition junction is the “root of the iris” and is the thinnest portion of the iris (0.5mm thick).
Which frames should not be heated?
polyamide, copolyamide, carbon fiber, carbon fiber graphite, or polycarbonate
conditions that falsely elevated A1c levels (5)
iron deficiency anemia
Any process that slows erythropoiesis increases A1c by maintaining an older erythrocyte cohort in the blood plasma (i.e. aplastic anemia).
alcoholism
hyperbilirubinemia
certain medications (high doses of salicylate, chronic opioid use)
False lower A1c levels: (6 conditions)
Any process that shortens the linespace of erythrocytes (i.e. hemolytic anemia, chronic kidney or liver disease).
Vitamins C and E (by inhibiting glycosylation of glucose to hemoglobin).
Pregnancy
Splenomegaly
Rheumatoid arthritis
Certain medications (antiretrovirals, ribavirin, and dapsone)
Systolic pressure resulting primarily from contraction of which chamber of the heart?
the left ventricle
When is diastole pressure occurring?
As the heart relaxes and blood flows out of the aorta (lowest measure of blood pressure exerted on the vessel walls)
How do prokaryotic cells create new genomes/reproduce?
transformation (uptake of naked DNA), transduction (transfer DNA from bacterium to another via virus), and conjugation (btwn donor w/ plasmid and recipient bacteria; donor imitates w/ a sex pilus).
Equation for finding minimum anti-refractive coating thickness.
Thickness = wavelength / (4 x index of coating)
Equation for PD caused by light deviation
P = (100) (x/d); P = PD, x = total distance light is deviated (cm), d = total distance from prism to location where deviation is measured (cm)
spatial summation (scotopic system, rods) means _______ sensitivity and ______ resolution.
higher sensitivity and poorer resolution
Because a lot of information is gathered by the rods and given to one ganglion cell, the resolution is poor.
ANSI standard for sphere powers.
For sphere powers =/
ANSI standard for cylinder power.
Cylinder power 2.00D or less +/- 0.13D.
Kearns-Sayre syndrome triad
i. Progressive external ophthalmoplegia (CPEO), salt and pepper pigmented retinopathy, 1 or more systemic complications (heart block, cerebellar ataxia, abnormally elevated CSF protein).
prosencephalon (forebrain) becomes
telencephalon and diencephalon
Telencephalon becomes cerebrum (cerebral cortex, white matter and basal ganglia).
Diencephalon forms 4 distinct components including thalamus, subthalamus, hypothalamus, and epithalamus.
mesencephalon (midbrain) is located…..
Mesencephalon located below the cerebral cortex (telencephalon) and above hindbrain, does not differentiate any further.
Rhombencephalon (hindbrain), the third ventricle during early development, becomes…
myelecephalon and metencephalon
Myelencephalon forms medulla oblongata.
Metencephalon forms pons and cerebellum.
residual volume definition
volume of air remaining in the lungs after a maximal exhalation
expiratory reserve volume definition
maximal volume of air that can be exhaled at the end of a tidal exhalation
functional residual capacity
amount of air in the lungs following a tidal exhalation (expiratory reserve volume + residual volume)
vital capacity
maximal volume of air that can be exhaled after the deepest inhalation possible
total lung capacity
the total volume of lungs at maximal inhalation (vital capacity plus residual volume)
tidal volume
volume of air that is inhaled and exhaled during quiet breathing
telecanthus definition
describes increased distance between eyelids at the medial canthus
epicanthus
orbital fold or Mongolian fold of eyelid
EOG can detect what? And what’s a good arden ratio?
best’s disease (decreased arden ratio 1.80
Different waves of the ERG (ABC)
A: photoreceptors
B: bipolar/Muller
C: RPE
what does VEP detect?
MS, will be less than the normal 100msec response
What are the three things that make up the blood-aqueous barrier?
- endothelium of schlemm’s canal
- iris vessels
- non pigmented ciliary epithelium
**All have tight junctions.
What happens after a corneal abrasion?
- basal cell mitosis stops
- cells around defect lose attachment to BM and enlarge/migrate to create an epithelial sheet
- Hemidesmosomes created to allow proper adhesion between migrated cells and the BM
- basal cell mitosis occurs at a rapid rate
- wing cells do not undergo mitosis, only basal cells do
Anterior lens epithelium differentiation and formation…
anterior lens epithelium –> secondary lens fibers –> fetal nucleus
posterior lens epithelium transforms/produces…
posterior lens epithelium –> primary lens cells –> embryonic lens nucleus
Which blepharitis is this:
- greasy lid margins
- lashes that stick together (teepee lashes)
- scales are soft and may be seen anywhere along the eyelashes and lid margins
seborrheic blepharitis
Which blepharitis is this?
- hard scales at the base of the lashes (ccllarettes)
- erythema and telangiectasia of the lid margin
staphylococcal blepharitis
Define chalazion.
sterile, accumulation of lipogranulomatous material caused by blocked meibomian gland orifices
Where is thymosin found? and what does it do?
found in Thymus, a hormone essential for T-cell maturation
- majority of upper eyelid
- temporal aspect of lower lid
- conjunctival vessels
all drain into which lymph nodes?
preauricular (parotid) lymph nodes; located below the base of the mandible
- 1/3 of nasal aspect of upper lid
- medial 2/3rds of the lower lid
- nasal portion of the conjunctival vessels
all drain into which lymph node?
submandibular nodes; located below the base of the mandible
Dx for a patient who is +Sx for:
- lacrimation
- photophobia
- decreased vision
- red eye
- severe pain that is highly out of proportion to the ocular signs
- likes to go in hot tub w/ contact lenses on
And how would you treat it?
acanthamoeba keratitis
Tx: chlorhexidine gluconate 0.02% q1h or polyhexamethylene biguanide (PHMB) 0.02% q1h for 72-96 hrs; then taper to q2h for 2-4 weeks, then taper again to aid for 6-12 months. Use along w/ neosporin® (polymyxin B + bacitracin + neomycin) q1h and/or Brolene® (dibropropamidine isethionate) q1h. Also w/ oran antifungals (–azole)
most common cause of episcleritis
idiopathic; other causes include gout, Herpes zoster, Crohn’s disease, syphilis, Lyme disease, SLE, and RA
define snow-banking
Seen in in pt w/ intermediate uveitis where inflammatory cells can be observed lying over the inferior pars plana.
etiology of the aqueous fluid appearing hazy/cloudy (flare, smoke in a dark room) in the anterior chamber
flare = increased protein in aqueous fluid and is seen in associated w/ cell (d/t breakdown of blood-aqueous barrier as a result of trauma, infection, inflammation due to uveitis, scleritis, keratitis, or ocular surgery).
Cells will appear as small white particles floating in the anterior chamber.
Define non-granulomatous KPs
neutrophils + lymphocytes and clinically resembles small, discrete, fleck-like, linear, or stellate corneal endothelial opacities.
Define Mutton-Fat KPs
granulomatous involvement, epithelioid cells + macrophages, larger, thicker, fluffy, greasy or waxy look; fewer in number 10-15.
define red KPs
when RBCs are present in the anterior chamber in addition to inflammatory cells (hemorrhagic uveitis)
What is the normal blood plasma level of bilirubin?
should be below 1.2 mg/dL
corneal collagen cross-linking is a surgical procedure that involves what?
UV-A light + B2 (riboflavin)
Where are Vogt’s striae found and which diseases?
- fine vertical lines deep w/in stroma
- disappear w/ external pressure
- present most commonly in keratoconus, but also w/ PMD
ophthalmia neonatorum secondary to Neisseria gonorrhoeae presentation
- development w/in 2-6 days postpartum
- hyper acute conjunctivitis
- bilateral
- periorbital edema, conjunctival chemises
- +++ purulent discharge
ophthalmia neonatorum d/t chlamydia trachomatis
- mild/moderate symptoms of unilateral/bilateral conjunctivitis
- presentation 5-14 days after birth
- most common cause of ophthalmia neonatorum
- lid edema, conjunctival chemises, punctate corneal opacities, occasionally micropannus formation
average imbibition pressure (IP) of the corneal stroma
- 40mmHg
if the cornea is steeper horizontally (180º) then the image is ____________ in this meridian.
Steeper = minified;
Flatter = magnified
Which layer does a corneal arcus affect?
white/yellow circular band of cholesterol deposits in the stromal periphery
Organism most commonly associated w/ formation of a true membrane in cases of acute membranous conjunctivitis
Corynebacterium diphtheria infection.
Other organisms (Strep, N. gonorrhoeae, S. aureus, H. aegypticus, E. coli, adenoviruses, and herpes simplex) can all cause it, but the true membrane is synonymous w/ diphtheric conjunctivitis.
which refractive surgery is indicated for patients with recurrent corneal erosions?
PRK, photo refractive keratectomy
photo therapeutic keratectomy (PTK) has been shown to be useful in treating RCE, so might as well at a benefit of correcting patient’s refractive error
What occurs during accommodation?
- IOP decreases momentarily
- equatorial circumference of lens decreases (lens becomes more spherical)
- anterior surface of lens moves forward
- posterior surface remains stationary
- decrease anterior chamber depth
Which wavelength of light will scatter more w/ water vacuoles in the crystalline lens?
short wavelengths scatter more from small particle scatter (i.e. water vacuoles), so blue light may be more visually disturbing
Which histamine receptors plays a primary role in ocular allergies?
histamine binds to H1 receptors on nerves (causing itching) and blood vessels (causes chemises and erythema)
most frequent cause of contact lens-associated keratitis
pseudomonas aeruginosa
ANSI axis deviation for cyl 0.25D
14º
ANSI axis deviation for 0.50D cylinder
7º
ANSI axis deviation for 0.75D cylinder
5º
ANSI axis deviation for 1.00D, 1.25D, 1.50D cylinder
3º
ANSI for > 1.75D cylinder
2º
Advantages of Glass (and a huge disadvantage)
Advantages:
- high index of refraction = thinner lenses
- high Abbe number = less chromatic aberration
- glass blocks UV light
- very resistant to scratching
Disadvantages:
- high specific gravity
Volume, weight, and occupation of vitreous in eye.
4mL, 4.0grams, 2/3 bulk of eye
where are muller cell bodies found in the retina?
INL, inner nuclear layer
Information from the left visual field of Right eye ultimately ends up processed where?
The right dorsal LGN (lateral geniculate nucleus).
Which species can invade an intact cornea?
Neisseria (gonorrhoeae)
define contact dermatitis
- scaly, rough skin
- can be swollen, but w/o discharge or swollen pre-auricular nodes
- type 4 allergic reaction
define EKC (epidemic keratoconjunctivitis)
- tender pre-auricular nodes
- viral origin
- rarely see copious discharge, generally watery discharge
3 signs commonly associated w/ 3rd nerve cranial nerve palsy
- intorsion of the eye, which increases in attempted downsize
- limited depression of the involved eye
- normal abduction of the involved eye
Which muscles would a 3rd nerve palsy affect?
- SR, IR, MR, and IO
- levator
- pupil sphincter
- accommodative fibers
What does Avelino dystrophy (granular dystrophy type 2) affect?
histological changes consistent w/ abnormal deposition of amyloid and hyaloid in the stroma
Where does granular dystrophy type 1 affect?
abnormal amorphous hyaline deposits only in the corneal stroma
Where does macular dystrophy affect?
abnormal aggregations of GAGs as well as unusually close packing of collagen fibrils in the corneal lamellae
Anticonvulsant drug phenytoin (Dilantin®) can lead to which ocular side effect?
- nystagmus
- ophthalmoplegia
- mydriasis
- miosis
- diplopia
Weber’s test is used for what?
to distinguish between conductive or sensorineural hearing loss
Eustachian tube
also known as the auditory tube or pharyngotympanic tube, is a tube that links the nasopharynx to the middle ear. It is a part of the middle ear. In adult humans the Eustachian tube is approximately 35 mm long and 3 mm in diameter.
Define albumin
predominant protein in plasma, which makes up 50-60% of the total blood volume
what is plasma made of?
50-60% of total blood volume, made up of:
- water (90%)
- proteins
- dissolved gases
What is the cellular component of blood comprised of?
40-50% total blood volume.
- white blood cells
- platelets (second largest constituent)
- RBCs (bulk of cellular portion)
define agglutination
clumping of the blood, can lead to blockage of blood vessels causing tissue damage and/or death
Dx diabetes via Hemoglobin A1c
6.5%
Dx diabetes via fasting plasma glucose
> 126 mg/dL
Dx diabetes via 2 hour plasma glucose
> 200 mg/dL
Why is metformin such a great tx of choice for diabetes?
- only drug that prevents cardiovascular complications
- drug w/ least adverse effects and lower risk of hypoglycemia
- generally used for DM type 2
strategy for correction of SA (spherical aberration) and coma
- Best-form lenses
- aspheric lenses
- small stop
- lens systems (doublet)
Strategies for correcting oblique astigmatism (OA)
- Tscherning’s ellipse (Ostwald, Wollaston)
- Corrected curve lenses = point-focal form
Strategies for correcting curvature of field (CoF), as seen via movie screens.
- Tscherning’s ellipse (Ostwald, Wollaston)
- corrected curve lenses = Percival form
So, know that tscherning’s ellipse can correct for oblique astigmatism and curvature of field.
When does oblique astigmatism occur?
occurs w/ monochromatic aberrations, pantoscopic tilt, and faceform tilt
This is only relevant in higher power lenses.
A minus lens tilted along a meridian induces ______ sphere power and _____ cylinder with its axis along the tilt meridian.
minus, minus
A plus lens tilted along a meridian induces _____ sphere power and _____ cylinder with its axis along the tilt meridian.
plus, plus
equation for chromatic aberration (LCA and TCA)
LCA = F/v
TCA = P/v
equation for spherical aberration (LSA and TSA)
LSA = F/n
TSA = P/n
define stops
physical objects which block the passage of light
define aperture stop (AS)
- limits the amount of light, determines brightness
- smallest stop as seen from object point
define field stop (FS)
- limits field of view
- smallest stop as seen from the middle of aperture stop (AS)
define pupils
- images of AS produced by lenses
- entrance pupil: produced by lenses in front of AS
- exit pupil: produced by lenses behind AS
define ports
- images of FS produced by
What is Fraunhofer d line?
587.56nm
Define Brewster’s angle.
Incident angle for which all reflected light is 100% linearly polarized.
For any larger or smaller incident angle, reflected light is not 100% polarized.
What can light be polarized by?
- transmission
- reflection
- scattering
equation for AR material
nf = (sq(ns))
nf = refractive index of the coating material ns = refractive index of the material(?)
what absorbs UVB?
- 100% of incident UV-C light (100-280nm) is absorbed by the cornea
- About 90% of incident UV-B light (280-315nm) is absorbed by the cornea
- Approximately 60% of incident UV-A light (315-400nm) is absorbed by the cornea
What absorbs UVA?
lens
According to Huygens principle, what is the relationship between aperture, diffractive spread, wavelength, and chromatic aberration?
- decrease aperture = increase diffractive spread
- decrease wavelength = diffractive spread decreases = reversed CA when compared to refraction
When do you observe Stoke’s shift?
in NaFl testing w/ the evaluation of GP lens fit; if there is a UV blockers – you’d hardly see the fluorescein
- Stoke’s shift is the energy difference between emitted and released emissions
Which lens material has the least amount of transmission getting to the eye?
As index increases, you get more reflection off the front and back surfaces.
1.80 hi-index plastic
refractive index of the embryonic nucleus (center of the lens)?
1.41; highest refractive index because it has the highest concentration of crystalline in the lens
corneal ulcer
SEI and epithelial defect
Staph marginal keratitis
SEI w/o epithelial defect
Corneal abrasion
epithelial defects w/o SEI following trauma
which muscles are affected by benign essential blepharospasm
- orbicularis oculi
- procerus
- corrugated muscle
which muscle is affected by myokymia?
- orbicularis oculi
Branches of CN-7
To Zanzibar By Motor Car
- temporal
- zygomatic
- buccal
- maxillary
- cervical
define Paton’s folds
circumferential retinal folds in RNFL associated w/ papilledema
define Fuch’s spots
hyper pigmentation in the macula from RPE hyperplasia, associated w/ high myopia
define Schaffer sign
pigment in anterior vitreous liberated RPE pigment, assume retinal tear caused by PVD
Type 4 collagen
- lens
Type 2 collagen
- vitreous
- stroma
- sclera
- cartilage (chondroitin sulfate - GAG, also contributes)
vitamin C
40x higher in vitreous than blood plasma
lens has the highest amount
Anterior uveitis causes a ________ (increase/decrease) in IOP.
decrease in IOP
- inflamed ciliary body produces less aqueous as compared to its basal level of secretion
What etiologies of anterior uveitis cause elevated IOP?
- Posner-Schlossman syndrome
- Herpes
- an increase in IOP is attributed to trabeculitis, decreases outflow of aqueous.
define Brushfield spots
- Downs syndrome
- whitest or grayish lesions that are found circumferentially around peripheral region of iris. they are areas of stromal hyperplasia.
iris lesions associated w/ granulomatous uveitis
- Koeppe (pupillary border, little "cap") _ Busacca (found in mid-iris stroma)
HLA-B27 is for…
- spondylarthropathies
ANA, antinuclear antibody
- Juvenile arthritis
- Lupus
angiotensin converting enzyme (ACE)
sarcoidosis
venereal disease research laboratory (VDRL)
syphilis
fluorescent treponema antibody absorption (FTA-ABC) is a test for what disease?
syphilis: STD caused by spirochete Treponema pallidum
define pars plicata
- anterior 1/3 of CB and the part of ciliary processes that secrete aqueous humor
define pars plana
- makes up the bulk of the ciliary body (posterior 2/3rd)
define collarette
- thickest part of the iris
- junction between central pupillary zone and peripheral ciliary zone
- 0.6mm thick
define pupillary ruff
- visible portion of the posterior pigmented epithelium of iris
where does active secretion of aqueous occur?
non-pigmented ciliary epithelium
Where does the transition from squamous corneal epithelium to columnar conjunctival epithelium occur?
limbus (junction of cornea/sclera).
- Also the place where there is termination of Bowman’s layer, Descemet’s membrane and the corneal endothelium.
- The Palisades of Vogt are radial projections of the limbal epithelium that extend into the cornea; it is an area where corneal epithelial stem cells reside.
What is flare?
protein (in anterior chamber)
Which nodules are associated with granulomatous uveitis and found in the mid-iris stroma
- Busacca nodules
location of Berlin nodules
anterior chamber angle (found via gonioscopy)
location of Dalen-Fuchs nodules
- chorioretinal lesions representing epithelioid cells found between Bruch’s membrane and the RPE.
Component of trabecular meshwork from internal (posterior) to external (anterior).
Uveal meshwork –> corneoscleral meshwork –> juxtacanalicular tissue
What are the two most important factors in calculating the IOL power following cataract surgery?
- Axial length
- Keratometry
Purkinje image 1
- reflection from anterior corneal surface
- convex, virtual and erect
- brightest
- same size as object
Purkinje image 2
- posterior surface of cornea
- almost coincides w/ 1st Purkinje image, but smaller
- convex, virtual and erect
Purkinje Image 3
- Largest
- reflection off anterior plane of the crystalline lens
- convex, virtual and erect
Purkinje image 4
- smallest
- concave (mirror), real and inverted
- reflection off posterior surface of the lens
cataract associated w/ myotonic dystrophy
- multi-colored opacities (Christmas tree) cataracts (90% of patients)
cataract associated w/ atopic dermatitis
shield-like, dense anterior sub capsular plaques
cataract associated w/ neurofibromatosis
posterior sub capsular (PSC) or posterior cortical cataracts
cataract associated w/ Wilson’s disease
green “sunflower” cataracts
cataracts associated w/ Down’s syndrome
Cerulean or “blue-dot” cataracts
Mittendorf’s dot
on posterior lens
- remnant of the hyaloid system that was attached to the lens
embryological development of lens structures
- lens plate (placode), from surface ectoderm adjacent to the optic vesicle beginning around day 27 of development.
- lens pit
- lens vesicle (separates from the surface ectoderm around day 33, it’s a single layer of cells forming a hollow sphere)
- embryonic lens nucleus
- lens capsule (apparent at about 5 weeks, originates from the basement membrane of the surface ectoderm and from secretions of the lens epithelium)
define Elschnig pearls
typical finding that appears as vacuolated clusters on the back surface of the lens implant
most common cause of secondary cataract?
chronic anterior uveitis
Snyder’s rule estimates the resulting cylinder in lens rotation. What is the rule?
Rotates: estimated induced cylinder
10º: 1/3 of lens cylinder
15º: 1/2 of lens cylinder
20º: 2/3 of the lens cylinder
30º: 3/3 of lens cylinder
What is the 1, 2, 3 rule?
- ratio for 3 types of back toric GP lens associated astigmatism
(back toric lens, order w/ BCR difference of 2.00D)
1) 1.00D induced astigmatism
2) 2.00D radiuscope measured astigmatism
3) 3.00D lensometer measured astigmatism
With contact lens, a myopes must accommodate (more/less) than w/ a spectacle lens.
w/ CL, a myope must accommodate MORE than w/ SL
with contact lenses, a hyperope can accommodate more/less than w/ a spectacle lens
A hyperope accommodates LESS with contact lenses than they do with spectacle lenses.
With contact lenses a myopes must converge MORE than with spectacle lenses. A hyperopes can converge more/less with contact lens.
Hyperopes converge LESS with contact lenses than with spectacle lenses
How do you apply Knapp’s law for prescribing spectacle and contact lenses?
Spectacle lenses for axial ametropia.
Contact lenses for refractive ametropia.
What is angle H, angle S, and angle A?
- Angle H = horizontal objectiva angle of deviation
- Angle S = subjective angle of directionalization
- Angle A = angle of anomaly
What happens when Angle H = Angle S; Angle A = 0?
Normal correspondence
What happens when angle H does not equal angle S?
Anomalous correspondence.
(3 questions here)
What type of correspondence do you get when:
a) Angle S = 0, Angle A = Angle H
b) Angle S is not equal to 0
c) Angle S
a) Harmonious anomalous correspondence
b) unharmonious
c) unharmonious anomalous correspondence
W/ Teller acuity cards, what’s the grating acuity of a 10-month-old infant is expected to be approximately:
10 cycles per degree (20/60)
- 30 cycles per degree = 20/20
- 20 cycles per degree = 20/10
“each month is a cycle”
3 different types of simple epithelium and their specialties.
SAD
Secretion = cuboidal (i.e. Thyroid gland) Absorption = columnar (i.e. GI tract) Diffusion = squamous
Give an example of the 3 different types of exocrine secretion. (the following are their definitions)
Holocrine means that the entire cell w/ the product within it is shed into the lumen of the duct. So the cell is destroyed in the process.
Apocrine means that a membrane bound vesicle is secreted at the apex of the cell, it is pinched off and floats into the lumen.
Merocrine is the most common form of exocrine secretion. Here the products are simply exocytosed out of the cell.
Holocrine = meibomian glands, sebaceous glands
Apocrine = glands of Moll and goblet cells
Merocrine = main lacrimal gland
role and origin of calcitonin in the body
produced by parafollicular cells of the thyroid (oval cells between follicles)
Calcitonin decreases blood Ca2+ levels by inhibiting osteoclasts activity.
Osteoclasts are in charge of breaking down bone. Osteoblasts are in charge of building up bone.
role and origin of chief cells
Chief cells are located w/in the parathyroid gland (the 4 glands on posterior surface of thyroid).
Chief cells produce PTH (parathyroid hormone) which stimulates osteoclast activity. What does this do to Ca2+ levels in the blood?
- it will increase levels of calcium in the blood
What are the 3 Sinsss of the adrenal gland (w/in the cortex)?
- Salt (mineralocorticoids): zonula glomerulosa produces aldosterone
- Sugar (glucocorticoid): zonula fasciculata produces cortisol
- Sex (androgen): zonula retincularis produces the androgen
acidophiles (alpha cells) of the anterior pituitary produce
- growth hormone (somatotrophs)
- prolactin (mamotrophs)
Also, they stain pink/red d/t eosin.
basophils (beta cells) of the anterior pituitary produce
- (gondaotrophs) FSH and LH
- (thyrotrophs) TSH
- (corticotrophins) ACTH; excess ACTH causes Cushing’s disease
stain blue purple d/t hemotoxylin
what does the hypothalamus produce, and where is this stored?
hypothalamus produces ADH and oxytocin, these hormones are transported through the infundibular stem into the pars nervosa of the posterior pituitary.
- Posterior pituitary does not produce hormones. It is from the nervous tissue that originates in floor of the diencephalon.
mesoderm (the following are derived from this)
- mesenchyme
- connective tissue: blood, bones, cartilage
Cells of connective tissue include:
- fibroblasts, plasma cells, mast cells, macrophages, pericytes ( undifferentiated connective tissue)
Fibers of connective tissue:
- collagen, elastic fibers, and reticular fibers
glycosaminoglycans (GAGs):
- hyaluronic acid in the vitreous, chondroitin sulfate, keratin sulfate, and heparin
The brain, liver, and blood all have macrophages that are called by a different name. What are they?
- Brain = microglia (support cells in the CNS by phagocytizing pathogens and removing cellular debris)
- Liver = Kupffer cells
- Blood = monocytes until the cells leave the blood. After they leave, they are “macrophages.”
List the most to least common WBCs (making up
- Neutrophils (most common)
- Lymphocytes
- Monocytes
- Eosinophils
- Basophils (least common)
What starts up inflammation and what stops it?
histamine initiates inflammation, eosinophils stop it
- both are involved in allergic reactions (eosinophils are also associated w/ parasitic infections)
eosinophils: 2nd most common granulocyte
The different names of myelin as they are presented in each system: CNS, PNS
- CNS = oligodendrocytes (myelin sheath; cytoplasmic processes extend to wrap around multiple axons).
- PNS = Schwann cells (can provide myelin for only one axon), encased in neurilemma (glycoprotein basement membrane) that allows PNC neurons to regenerate.
- Note that in the CNS there are microglia and astrocytes which provide support for pathogen protection and capillaries.
stratum spinosum and stratum basal, which causes SCC and BCC?
SCC, squamous cell carcinoma = stratum spinosum
BCC, basal cell carcinoma = stratum basal
Type 3 collagen
- tunic media (middle layer of blood vessel)
- affected by Ehlers Danlos
medial lymphatics in the orbit drain into the _______________ lymph nodes while the lateral lymphatics of the orbit drain into the ______________ lymph nodes
medial lymphatics = submandibular lymph nodes
lateral lymphatics = parotid/pre-auricular lymph nodes
sympathetic and parasympathetic to the lung
sympathetic = bronchodilation, you want more air as you’re “running away.”
parasympathetic = bronchoconstriction; rest and digest – don’t need as much oxygen
Type 1 versus Type 2 pneumocytes in alveoli of the lungs.
Type 1: specialized for gas exchange, do not replicate. If they are damaged, they are replaced w/ more Type 2.
Type 2: simple squamous-like cells for surfactant (phospholipids and proteins mixture) to decrease surface tension for gas exchange, indirect involvement in gas exchange
different cells of the stomach and all that they secrete:
- goblet cells
- parietal cells
- chief/peptic cells
- enterochromaffin cells
- G cells
- D cells
- Goblet cells = mucous
- Parietal cells = HCl and intrinsic factor
- Chief/peptic cells = pepsinogen, an inactive enzyme that is cleaved into pepsin (the active form) in the presence of HCl.
- Enterochromaffin cells = histamine and serotonin
- G cells = gastrin (which stimulates parietal and chief cells)
- D cells = somatostatin
define albumin
The main protein in human blood and the key to regulating the osmotic pressure of blood. Chemically, albumin is soluble in water, precipitated by acid, and coagulated by heat. Found in egg white, milk, and (in particular) blood serum.
define these important neurotransmitters (NT) and where they are found (what structures they’re most associated with)
- GABA
- Glycine
- Cholinergic: nicotinic and muscarinic
- Adrenergic
- GABA: γ-aminobutyric acid; GABA is the most widely distributed inhibitory NT
- Glycine: inhibitory NT found in the brain stem, spinal cord, and retina
- Nicotinic: found in skeletal muscle and blacked by curare. Muscarinic is found in smooth muscle (but also in the cardiac muscle).
- Adrenergic: found in the sympathetic NS. Examples include epinephrine and serotonin (in the brainstem)
- Also important to note that acetylcholine is more associated w/ the parasympathetic nervous system and found at the NMJ (neuromuscular junction). Nicotinic Ach receptors are targeted by alpha-bungarotoxin (snake venom).
How many pairs of spinal nerves are there, are where do they innervate?
31 pairs
- Cervical (C1-C8): 1-4: neck, 5-8: upper extremities
- Thoracic (T1-T12): all on upper extremities
- Lumbar (L1-L5): 1-4: thigh; 4-5: thigh, leg, foot
- Sacral (S1-S5): 1-3 thigh, leg, foot; 2-4 pelvis
- Coccygeal: just 1 coccygeal nerve
Formula for power of a mirror.
Recall that concave mirror acts as a convex lens (+) power. Convex mirror = concave lens = (-) power.
P = (2n)/r
define complex cells
complex cells display a preference for direction, has to be in the correct position to elicit a response. There are no inhibitory or excitatory regions in the receptor fields.
which light scattering is responsible for the reddish-orange colors that are observed during a sunset?
- Rayleigh scattering
- The particles that scatter the light are smaller than the wavelength of the light passing through. The appearance of the blue sky during the day and the reddish hue of the sunset are due to Rayleigh scattering of light.
What do a shadownscope, radiuscope, V-channel gauge, and 7x comparator measure in a GP lens?
- shadowscope measures edge profile
- radiuscope measure BC of a RGP
- V-channel gauge = overall diameter of contact lens
- 7x comparator = handheld measuring magnifier that is useful for measuring the overall diameter, optic zone diameter, and peripheral curve diameter; and inspection for scratches
Gram negative versus gram positive.
The composition of a Gram-positive cell wall is relatively simple: it contains a thick layer of peptidoglycan, teichoic, and lipoteichoic acids. Gram-positive cells have only one plasma membrane.
- Gram negative has an outer and inner membrane to their cell wall. The outer membrane contains porin proteins (pores), lipopolysaccharides (O side chain, antigen), core polysaccharide, and lipid A (endotoxin).
sympathetic pre and post-ganglionic fibers
preganglionic: short, use acetylcholine
postganglionic: long, use norepinephrine
Describe Uhthoff’s phenomenon and which disease it is associated with.
Suggestive of optic neuritis associated w/ MS.
Transient vision loss d/t increase in body temperature (6% of MS pts).
Describe L’Hermitte’s phenomenon and which disease it is associated with.
Sensation of an “electric shock” that quickly travels down the back and into the limbs w/ flexure of the neck. Occurs in 30-40% of patients.
Suggestive of optic neuritis associated w/ MS.
What are the three symptoms that are suggestive of optic neuritis associated w/ MS?
- Uhthoff’s phenomenon
- L’Hermitte’s phenomenon
- INO, internuclear ophthalmoplegia; especially bilateral INO (15-30%)
INO: lack of Adduction on the affected side w/ contralateral nystagmus on ABduction; d/t white matter lesion on the MLF (poor conduction of ipsilateral CN3 and contralateral CN6)
What is Grave’s ophthalmopathy associated with?
- Thyroid-related ophthalmopathy (TRO)
causes of unilateral disc edema
- thyroid-related ophthalmopathy (Grave’s)
- sarcoidosis
- (collagen vascular disorders) rheumatoid arthritis, SLE, polyarteritis nodosa, Wegener’s granulmatosis
- orbital cavernous hemangioma (d/t location)
(following are infectious)
- syphilis
- TB
- neruroretinitis (cat scratch fever, syphilis, Lyme disease)
causes of bilateral disc edema
- papilledema
- GCA, eventual progression in 2 weeks unless treated w/ steroids
The 3 tests to order to rule out GCA
- CRP
- ESR
- platelet count
When CRP + ESR are elevated, you have 97% chance of GCA. Then you do a temporal artery biopsy for gold standard.
define orthograde flow
from eye to brain (disease w/ PRP laser, CRAO, RP, extensive GA)
define retrograde flow
from brain to eye (disease because eye is supposed to be higher pressure than brain, pituitary tumor)
central or centrocecal visual field defects
- toxic/nutritional optic atrophy: damage of papillomacular bundle at temporal rim of ONH.
- ARMD (central scotoma)
What is Foster Kennedy syndrome?
- rare condition caused by a frontal lobe tumor
- characterized by simultaneous optic disc edema in one eye and optic disc atrophy in the fellow eye
an optic nerve pit is ______ while an optic nerve coloboma is ______
optic nerve pit = inferior/temporal
optic nerve coloboma = inferior/nasal
causes of an APD
- dense vitreous hemorrhage
- extensive retinal damage (i.e. retinal detachment)
- optic nerve damage (i.e. glaucoma)
- optic chiasm damage that involves the adjacent optic nerve
- Will NOT result in APD: cornea, iris, crystalline lens, optic tract, optic radiations, occipital lobe).
Describe which pathway is abnormally effected.
- when transilluminator light is initially shown to OD, OS will be dilated.
- when transilluminator light is switched to OS, the OS will stay dilated
- when transilluminator light is quickly switched back to the OD, the OD will stay constricted
Abnormal efferent pathway OS
Ddx for abnormal pupil that is mitotic (larger difference in pupil size in the dark).
- Horner’s syndrome
- Argyll Robertson pupil (tertiary syphilis)
- Uveitis w/ posterior synechiae
Ddx for abnormal pupil size that is fixed and dilated (larger difference in pupil size in the light).
- CN 3 palsy
- ADie’s tonic pupil
- iris sphincter trauma
- pharmacologic dilation
“triad” of congenital glaucoma
- photophobia, epiphora, and blepharospasm
- cloudy corneal edema, enlarged globes/corneas (>12mm), hypoplasia of iris stroma, and cupping of optic nerve.
Drugs that have a side effect of dry eye.
- drugs used to treat HTN (hydrochlorothiazide)
- Isotretinoin-type drugs for treating acne (Accutane®)
- Oral antihistamines (cetirizine, Zyrtec®)
- oral contraceptives (drospirenone, Yasmin®)
What are the 3 characteristics of retinal photoreceptor cells.
- photoreceptors produce graded potentials
- photoreceptors hyperpolarize in response to light stimulus
- photoreceptors release less neurotransmitter (glutamate) in response to light
define polymegathism
refers to a change in cell size; occurring primarily in endothelial cells
define pleomorphism
altering of endothelial cell shape; occurring in patients who wear contact lenses w/ low oxygen permeability
describe Snyder’s rule w/ a contact lens and rotation/induced astigmatism
- A contact lens rotated 10º away from proper axis will result in manifestation of astigmatism 1/3 original power at some oblique angle.
- 15º = 1/2 original power at oblique angle.
- 30º = full amount of cylinder power in over-refraction at oblique angle.
describe vitamin C
- water soluble
- stored in WBCs
- antioxidant that serves as cofactor (enzymatic pathways and iron absorption).
- deficiency = scurvy
define vitamin B3
- also known as Niacin
- for fat and carbohydrate metabolism
- deficiency of vitamin B3 = Pellagra (diarrhea, dementia, and dermatitis)
- can treat hyperlipoproteinemia
describe vitamin B6
- aka Pyridoxine
- coenzyme for hemoglobin formation
- amino acid / protein metabolism
How would you classify a reaction of overall change in free energy that is negative?
- delta G here is (-)
- exergonic
- energy of the reactants is greater than energy of end products, therefore, the formation of products leads to a release of energy
- spontaneous
- favors formation of products
- at equilibrium, the concentration of products is greater than the amount of reactants
- this means that a positive change in free energy is non-spontaneous and endergonic (requires energy)
Which hormones are synthesized by the hypothalamus and stored in the posterior lobe of pituitary?
- oxytocin and vasopressin (aka ADH, antidiuretic hormone)
Which hormones are synthesized by the pituitary and stored in the anterior pituitary lobe?
- Thyrotropin (TSH)
- follicle-stimulating hormone (FSH)
- prolactin
- growth hormone (GH)
Which glands secretes saliva?
- parotid glands, in front of each ear
- sublingual glands (beneath the tongue)
- submandibular glands (lower jaw in the floor of the mouth)
What’s the correct order of stages of human development during prenatal period?
Zygote –> morula –> blastocyst –> embryo –> fetus
- Zygote = Egg + sperm
- developing baby = morula
- blastocyst; marked by presence of a ball of cells possessing a surface layer along w/ an inner mass of cells.
- embryonic stage = 2 wks to end of 8th week
- fetal stage = beginning of 9th week until delivery (approx 39 wks post fertilization)
define pinna
Pinna is also called auricle. It is located outside of the head and serves to channel sound towards the middle and then to the inner ear and brain for processing.
What’s responsible for the “popping” of the ear?
Eustachian tube
Which enzyme does the binding of insulin to its receptor activate?
tyrosine kinase (attached to the insulin receptor on the inside of the cell)
Phosphorylation of the glucose transport protein which then relocates to the cellular membrane, where it facilitates the import of glucose
Most patients have a resting (tonic) level of accommodation of what?
1.0 diopters
Also known as a “lead of accommodation.” it is 0.50 to 1.00D.
Your patient has +10.00D lenses for near. What type of prism and the amount is necessary to have in an effort to maintain binocularity?
12 PD BI per eye
- Rule of thumb: amount of base-in prism added to the spectacle Rx should be 2PD greater than the dioptric amount of the optical correction in each eye.
define metamers
two stimuli that are physically different but appear to be the same
- the additive property states that if you add an equal amount of a new wavelength to each meatier, they will remain metamers
- scalar property: if the intensities of the meters are increased of decreased equally, they will remain metamers
- associative property of metamers: if a metamer is substituted for another, the two metamers will still match
What can you do to decrease dimple veiling in a RGP patient?
Dimple veiling is d/t poor tear exchange under RGP which leads to entrapment of bubbles of carbon dioxide under the central curvature of the lens.
- decreasing overall diameter
- flattening BC
- decrease diameter of optic zone
- reduce the vault of lens
Damage to inferotemporal cortex may result in deficits in analyzing…
- form
- color
Which regard to a conventional flat synapse made by a bipolar cell, which of the following are true?
- it is located in the inner plexiform layer
- the neurotransmitter is glutamate
Recall: flat synapses of bipolar cells are off-center
At a distance of 20ft a patient has a contrast sensitivity function (CSF) that peaks at 4 cycles/degree. When measured at 40 ft, this patient’s CSF is expected to peak at…
4 c/d
Because patients will still see 4 cycles per degree. The image has to be a little bit larger if it’s moved further away, but they’re still able to see the same. You can think of it as “the VA is the same even if the distance changes.”
This is meant to be a simple concept.
Which of the following laws governs temporal summation and can be expressed as the relationship between intensity and duration of a stimulus within a critical period?
Bloch’s = temporal
Ricco’s Law = spatial
A person missing long wavelength cones is a(n):
protanope (missing “red” cones)
Tritanope: missing blue (short wavelength cones)
Deuteranope: missing green (medium wavelength cones)
In a block of 100 trials of a yes/no signal detection experiment, the signal is absent on 10 trials. The observer has 80 hits and 5 false alarms (false positives). How many responses are correct rejections
5
Observer had 5 false alarms (false positives). Since 5 were false positives, you have 10 - 5 = 5 correct rejections.
False positive: patient thinks it is correct, but it is wrong
Physically identical gray spots are centered on 2 backgrounds, one white and the other black. A normal subject will perceive that the:
gray spot on the black background is brighter
So if you have a gray spot on a white background, it will be dimmer.
A rod monochrome views the following four patches of a monochromatic light: 440nm, 510nm, 555nm, and 565nm. Each patch produces 20 quantal absorption. Which is brightest?
- All are equally bright.
Pt scores low on both horizontal and vertical portions of Developmental Eye Movement test (DEM), but the ratio and error scores are normal, what’s concluded?
- normal oculomotor function, poor automaticity
- Automaticity is the measurement of number calling ability – this is determined by adding A and B tests together.
example of negative single-stranded RNA viruses
- paramyxoviruses that cause mumps and measles
example of double-stranded RNA virus
- rotavirus, causes infantile diarrhea
Which rate of elimination will result in a drug being eliminated at a constant rate?
- zero order rate or elimination; this is independent of the concentration of the drug (increasing the amount will not = more drug being eliminated).
- 1st order rate of elimination is dependent on the concentration of the drug (increase amount = increase drug elimination).
2nd and 3rd order rates of elimination do not exist in pharmacokinetics.
Which conditions match w/ the following discharges:
a. mucopurulent
b. purulent
c. mucoid
d. watery or serous discharge
a. mucopurulent = bacterial conjunctivitis
b. purulent discharge = gonococcal infections.
c. Mucoid = is a common sign/symptom of chronic allergic conjunctivitis and dry eye syndrome
d. water/serous discharge = acute allergic conjunctivitis or acute viral infections
What is Ricco’s law? equation and definition
K = IA (K = constant, I = stimulus intensity, quanta/area, A = stimulus area)
According to Ricco’s law, the threshold number of quanta necessary for stimulus detection is constant, with stimulus intensity and stimulus area having a reciprocal relationship.
What do epitope and paratope interaction with?
Epitope = location of the antigen that reactions w/ the antibody
Paratope = region of the antibody that reacts with the antigen
Glucagon is released by ________ and targets _________ & ____________.
Released by pancreas and travels to the liver and adipose tissue.
Released during times of depressed blood glucose levels.
Contrast equation.
Contrast = (target luminance - background luminance) /
(target luminance + background luminance)
In this question, the target luminance is reported as 50 units of light while the background is measured as 100 units of light.
Contrast = (50-100) / (50+100) = 50/150 = 33 percent
Definition of oculoglandular syndrome. Most importantly what’s the other name for it and when does it occur?
Also known as Parinaud’s oculoglandular syndrome.
Parinaud’s oculoglandular syndrome is the combination of granulomatous conjunctivitis in one eye, and swollen lymph nodes in front of the ear on the same side. Most cases are caused by cat-scratch disease, although it is an unusual feature of this condition. Occasionally it may be caused by other infections. It should not be confused with the neurological syndrome caused by a lesion in the midbrain which is also known as Parinaud’s syndrome.
define P wave on an ECG (electrocardiogram)
lasts for approx 80 ms and is generated by atrial depolarization
define pilomotor response
body hair is caused to stand erect, creating air pockets that serve to retain heat
- as in decreased temperature
based on Munsell color system, define Chroma
Chroma = saturation, it represents the purity of the color
First synapse of the visual pathway.
occurs in the OPL
define IgM
possess the heaviest molecular weight and is the antibody responsible for activation of the complement pathway as well as being the first antibody produced in response to an infection
IgA definition
- secretory antibodies, located in mucous membranes.
- Providing protection of the lungs and GI tract from infection. Can be detected in some mammalian milk transferred for passive immunity.
Define IgD
- bound to the surfaces of B-lymphocytes and are only a minor blood component
Define IgG
- long term protection, i.e. viruses
- predominant antibodies found in blood
- lightest antibody
- only one who can cross placenta
- found in milk produced shortly after devilry of child
IgE
- allergic reactions & inflammation
- parasitic infections (usually w/ the eosinophils)
How to loosen a tightly-fitting gas-permeable lens?
- (most common) flattening base curve
- decrease optic zone
- decrease overall diameter (OAD)
- widen the peripheral curve system
- flatten the peripheral curve system
Which 2 pupil anomalies would cause anisocoria that is prevalent in bright lighting?
- Acute ADie’s tonic pupil; over time, an ADie’s pupil may become miotic
- Oculomotor palsy (CN-3)
- iris sphincter damage (trauma): usually associated w/ a torn pupil margin, or iris transillumination defects
define prosopagnosia
ability to recognize faces is impaired while other aspects of visual processing remain intact
define akinetopsia
condition in which patients cannot perceive motion but can acknowledge stationary objects w/o trouble; “motion blindness”
Type of headache characterized by the presence of a severe unilateral headache w/ periocular pain and an ipsilateral Horner syndrome
Raeder’s paratrigeminal neuralgia
- headache follows V1 (ophthalmic division)
- symptoms last from hours to weeks, eventually resolves spontaneously
Headache characterized by multifocal, shark, quick, intense pains that occur around the areas of the skull, face and eyes.
ice-pick syndrome
- differentiated from trigeminal neuralgia in that pain in these cases does not follow the anatomical distribution of the trigeminal nerve.
Which headache usually occurs in patients under 10 years and is characterized by a recurrent, transient third nerve palsy, which develops after the headache.
- ophthalmoplegic migraines
Which headache is typically unilateral and oculotemporal in location, associated w/ deep, sharp, excruciating pain that may last 10 minutes to 2 hours. These headaches would typically occur on a daily basis for a period of several weeks; thus they are given their name.
cluster headaches
Which headaches are the most common type of primary headaches in adults? The pain in these headaches usually radiates from the lower back of the head, the neck, or the eyes. The pain is commonly bilateral and is usually mild to moderate but can be severe in some patients.
tension headaches are the most common primary headache in adults
define polydipsia (hint: in diabetic patients)
sign of chronic excessive thirst
define polyphagia (also in DM patients)
excessive hunger
MOA of beta-blockers
decrease aqueous production
- Aqueous production is reduced at night when a patient is laying down and therefore beta-blocker are least effective at this time, so it’s most effective in the morning.
During fetal development, which quadrant of the peripheral retain is the last to become fully vascularized and when?
- temporal
- 1 month after birth
Which frame material requires high heat (up to 200ºC) for frame insertion?
optyl
Which materials utilize only minimal amounts of heat if lenses cannot be “cold snapped” ?
- cellulose acetate
- cellulose proprionate
- carbon fiber
Which materials should not be heated at all for the lens insertion process?
- polycarbonate
- polyamide materials
The lungs of a fetus are collapsed in the womb, the majority of blood bypasses the lungs through a hole in the heart known as what?
foramen ovale, this is a term used for the skull and the heart
- This foramen acts as a door between the right and left atria, allowing passage of oxygenated blood from mother’s placenta to the brain of the fetus. The majority of blood enters the atria and is shunted into the arterial duct, which bypasses the lungs.
Where does angle recessive occur?
- a tear between longitudinal and circular muscles of ciliary body
Where does iridodialysis occur?
involves a detachment between the iris root and the ciliary body
What does cyclodialysis cleft involve?
detachment between ciliary body and the scleral spur
Risk factors of chronic obstructive pulmonary disease (COPD).
- frequent childhood infections
- low birth weight
- an alpha-1 antitrypsin deficiency
Unlike asthma (involved CD4 T cells), COPD involved CD8-T cells. When there is severe asthma, the two symptoms and causative factors may then overlap.
Which primary germ layers of embryonic development take part in the development of ocular structures?
- ectoderm
- mesoderm
Endoderm is involved in development of the GI tract, respiratory tract, endocrine organs, urinary bladder and auditory epithelium.
Which theory describes the change in peak spectral sensitivity from higher wavelengths to lower wavelengths as the surrounding illumination decreases?
The Purkinje shift.
- as we transition from viewing w/ the scotopic system to the photopic system, the peak spectral sensitivity changes from shorter to longer wavelengths.
list all the hormones the anterior pituitary is responsible for synthesizing and secreting.
- thyroid-stimulating hormone, TSH
- growth hormone, GH
- adrenocorticotrophic hormone (ACTH)
- follicle-stimulating hormone (FSH)
- luteinizing hormone (LH)
- melanocyte-stimulating hormone (MSH)
What does the posterior pituitary lobe store?
- oxytocin
- antidiuretic hormone, ADH
Keplarian
- (+) obj lens, (+) ocular lens; like your BIO
- real, image is outside of the focal points
- inverted
- your using a convex lens
Galilean
- (+) objective lens, (-) ocular lens
- virtual
- erect
- this is d/t minus lens
