EPT6 Flashcards
What mechanism explains the iris color change sometimes noted in pts on topical ophthalmic latanoprost?
Increased pigmentation associated with INC of melanin within iridial melanocytes
Which is the MOST common cause of genetic visual impairment in infants and children?
Leber congenital amaurosis
What is sorsby dystrophy?
Peripheral choroidal and outer retinal disease that typically manifests in adulthood
When does choroideremia cause visual impairment?
Middle adulthood
Which technique for measuring aniseikonia is considered to be the MOST accurate?
Space eikonometer
Rare to have, most clinicians just estimate aniseikonia with the rule that for every 1.00D of power difference, there will be ~1% induced aniseikonia
If you add two soft CL’s how do you figure out the resultant power and axis?
- Resultant cyl axis is between the cylinder lens axis
- Resultant cyl axis is closer to the CL with more cyl power
- Sum of spherical equivalents of the 2 cyl lenses will equal the spherical equivalent of the resultant cyl lens
DEC synthesis of type 1 collagen is MOST likely result in which of the follow? Select 2
a. INC IOP
b. Corneal thinning
c. Blue sclera
d. Cataract formation
e. Vitreous syneresis
b. Corneal thinning
c. Blue sclera
NOTE: type 1 collagen is primarily located w/in the cornea and sclera. Thus, DEC synthesis of type 1 collagen is MOST likely to result in scleral thinning (noted as a blue sclera due to the visibility of the underlying uvea), as well as corneal thinning
Type I collagen is found in which part of the cornea?
Stroma (450 um)
Where is type IV collagen found in the cornea?
Basement membrane & Descemet’s Membrane
Where is Type II collagen found in the cornea?
Bowman’s membrane
What mucin types bind to goblet cells?
Mucin 1,4,6
EBMD and Meesan affects what part of the cornea?
Basement Membrane
NOTE: thcikens w age, 8-10 weeks for regeneration
Band Keratopathy, Pterygia, Reis-buckler dystrophy, and Keratoconus affects which part of the cornea?
Bowman’s Membrane
NOTE: strong barrier to injury, acellular, embryologically layed down (no regeneration)
Macular dystrophy, granular dystrophy, and lattic dystrophy affects which part of the cornea?
Stroma
NOTE: hydrophilic, nerves enter here and move anteriorly
What are the 2 effects of PTH?
- Stimulation of osteoclast activity in bone
2. Stimulation of calcium reabsorption by the kidney
The midbrain is involve in the control of which of the follow (select 3)?
a. Sensory innervation of the cornea
b. Innervation of the lateral rectus
c. Innervation of the Superior Oblique
d. Innervation of the levator palpebrae superioris
e. Motor activity to the muscles of facial expression
f. Pupillary constriction
c. Innervation of the Superior Oblique
d. Innervation of the levator palpebrae superioris
f. Pupillary constriction
NOTE: the midbrain contains nuclei for CN3/4, and the EW nucleus.
Autoimmune damage to the salivary glands is MOST likely associated with which of the following clinical findings?
a. 11mm wetting after 5 min on Schirmer 1 testing
b. 6 sec TBUT
c. 4mm wetting after 5min on Schirmer 2 testing
d. 11mm wetting after 15 sec on phenol red thread test
c. 4mm wetting after 5min on Schirmer 2 testing
NOTE: autoimmune damage to the salivary glands (including the lac gland) causes Sjogren’s syndrome which is associated with ADDE. <5mm of wetting after 5min on Schirmer 2 testing is suggestive of ADDE
What is the MOST common infectious cause of post-operative endophthalmitis?
Gram (+) bacteria
NOTE: our lids and lashes have gram (+)
What is the MOST common clinical finding in toxic anterior segment syndrome following cataract extraction is?
Corneal edema
NOTE: marked diffuse corneal edema with little to no post seg inflammation Dx w/in first 12-48 hours following cat extraction. PS & suppurative conjunctivitis are LESS common but possible.
Zeaxanthin and lutein are xanthophyll pigments that are PRIMARILY located where?
Inner segments of PR
A posterior vitreous detachment is MOST commonly the result of:
a. INC type 2 collagen content of the vitreous
b. Formation of lacunae and inward collapse of the vitreal cortex
c. Loss of Weiger’s ligament in the anterior vitreous
d. Separation of the vitreous base from the retina
b. Formation of lacunae and inward collapse of the vitreal cortex
NOTE: result of INC vitreal liquefaction, which results in lacunae formation and inward collapse of the cortex.
When does separation of the vitreous base from the retina most often occur?
Trauma and is NOT a cause of PVD
What is the DIRECT role of RPE in the visual cycle?
Converting All-trans-Retinol to 11-cis retinol –> then oxidized to 11-cis retinal**
NOTE: RPE transports All-trans retinol into its cytoplasm via cellular retinol binding protein, where it is sequentially converted into 11-cis retinal. Many rod-cone dystrophies occur as a result of interruptions to this pathway
Using a high powered add will have all of the following effects EXCEPT:
a. DEC WD
b. DEC FOV
c. DEC lateral magnification
d. INC relative distance magnification
c. DEC lateral magnification
What is duane syndrome exactly?
A group of EOM disorders characterized by abduction and/or adduction deficits due to misrouting of CN6 & irregular innervation of a branch of CN3
What is the index of refraction for an ideal thin film that minimizes reflections for an anterior chamber IOL (n=1.45) w/in the aqueous humor?
1.392
nf = (nLnm)^0.5
nf=(1.451.336)^0.5=1.392
nf=index of film
nL=index of IOL
nm=index of aqueous
For aquired and asymmetric color vision defects, which eye should you test monocularly first?
The POORER seeing eye!!!
Which layers are absent at the foveola and why?
No bipolar cells No ganglion cells No INL No IPL No NFL
in order to minimize light scattering as light travels to the cone PR
Which group of vessels exits the outer wall of schlemm’s canal?
External collector channels (aka aqueous veins of Ascher) –> Episcleral plexus –> Anterior ciliary veins –> muscular veins –> S/I ophthalmic veins –> CS
Which of the following is NOT an association of an acute, unilateral, non-granulomatous uveitis (SELECT 3):
a. Juvenile rheumatoid arthritis
b. Behcet’s disease
c. Fuchs’ heterochromic iridocyclitis
d. Ankylosing spondylitis
e. Reactive arthritis
f. Tuberculosis
a. Juvenile rheumatoid arthritis
c. Fuchs’ heterochromic iridocyclitis
f. Tuberculosis
(a) and (c) are both chronic non-granulomatous uveitis, most often uni in Fuch’s and bilateral in JRA
(f) is associated with chronic, bilateral, granulomatous uveitis that may be anterior, posterior, or panuveitis
What is the MOA of Spironolactone?
It inhibits the actions of aldosterone in the late distal convoluted tubule (DCT) & the collecting duct of the nephron, leading to DEC absorption of NaCl & DEC excretion of K+
Furosemide inhibits which cotransporter?
Na+/2Cl-/K+ cotransporter in the thick ascending loop of Henle
If a bacterium were susceptible to both penicillin and erythromycin, then it would NOT be appropriate to Tx the pt w both antibiotics at the same time bc?
Penicillin is ONLY effective against growing cells
Bc erythromycin inhibits cell growth, it will DEC the effectivity of penicillin if both medications are administered at the same time
Which wavelengths are we most easily able to distinguish?
495nm and 590nm
Which of the following CORRECTLY pairs the pt’s age w the MOST appropriate VA test?
a. 24 month old toddler who sits too close to the TV; broken wheel testing
b. 11-month old infant w/o vision concerns; Allen symbols
c. 9 month old infant w a suspected RET; ooptokinetic drum
d. 30 month old toddler who squints; teller acuity cards
a. 24 month old toddler who sits too close to the TV; broken wheel testing
Broken wheel testing is a forced choice test that is MOST appropriate for toddlers or children of pre-school age. Teller acuity cards, another forced choice method, are most appropriate for infants ages 6-18 months.
Allen symbols are most appropriate for pre-school children (3 years of age or older) rather than an infant
The OKN drum only assesses activity within the visual cortex & is not appropriate for determining the presence of strab or the risk of amblyopia
Your pt w a Hx of RA presents w a complaint of redness OD w/o associated pain. You note focal blue-gray areas of the sclera w mild conjunctival injection and no associated keratitis. What is the MOST likely Dx?
Scleromalacia perforans
NOTE: also known as necrotizing scleritis w/o inflammation. It is a common form of scleritis in pts with severe RA. Pts present w a bluish-gray hue of the sclera due to thinning that results from rearrangement of the scleral collagen fibers after resolution of the inflammation. Pts ofte have minimal hyperemia & pain.
Nodula
A 45 year old female complains of bilateral ocular burning, tearing, and a FB sensation that progressively worsens throughout the day. She also reports a Hx of chronic dry mouth. Which of the following is MOST appropriate to further evaluate this pt’s symptoms?
Salivary gland biopsy
R/O sjogren’s
What is the MOA of ophthalmic trifluridine?
It prevents viral DNA replication by inhibiting thymidine synthetase
A pt who has experiences a TBI complains of difficulty finding the start of the next line when he finishes reading a line of text. Which of the following is MOST likely cause of his complaints?
a. Bitemporal hemianopsia
b. Left homonymous hemianopsia
c. Right homonymous hemianopsia
d. Binasal hemianopsia
b. Left homonymous hemianopsia
A pt who smokes cigarettes notices a gradual onset of labored breathing and shortness of breath. He has a reduced FEV1/FVC ratio. Which of the following is the MOST likley Dx?
Pulmonary emphysema
Enlarged air spaces & decreased elastic recoil
- Dyspnea
- Tachycardia
- REDUCED FEV1/FVC ratio
Which of the following wavelengths of light is MOST likely to damage the retina of a phakic elderly adult?
a. 285 nm
b. 370 nm
c. 310 nm
d. 210 nm
b. 370 nm
Recall:
UVA 400-315
UVB 315-280
UVC 280-100
UVC is absorbed by tears, cornea, and aq humor
UVA and UVB will be transmitted by the lens to the retina in a young pt
With age UVB is absorbed and almost all of UVA light
What is Kearns-Sayre Syndrome? What are some ocular features?
Kearns-Sayre syndrome is considered a mitochondrial myopathy in which mitochondrial DNA deletions result in a clinical triad of signs.
These signs include ocular features such as progressive external ophthalmoplegia (CPEO) and “salt and pepper” pigmented retinopathy (with predilection for the macula), as well as one or more systemic complications which can include heart block, cerebellar ataxia, or abnormally elevated cerebrospinal fluid protein.
Which of these statements are FALSE about a sphero-cylindrical lens OR for a SCL?
a. If the axis of the OR is the same as the axis of the spectacle Rx, INC cyl power in the soft toric CL
b. If the axis of the OR is 090 degrees from the axis of the spectacle Rx, DEC the cyl power in the SCL
c. For every 5 degrees of misalignment btwn the soft toric CL and the axis of the spectacle Rx, 1/4th of the original cyl power will manifest in the OR
d. If the axis of the OR is oblique compared to the axis of the spectacle Rx, the soft toric CL has rotated
c. For every 5 degrees of misalignment btwn the soft toric CL and the axis of the spectacle Rx, 1/4th of the original cyl power will manifest in the OR
NOTE: for every 5 degrees of misaligment btwn the soft toric CL position & the spectacle Rx, approx 1/6th of the original cyl power in the spectacle Rx will manifest in the sphero cylindrical OR.
If the axis of the OR and spectacle lens Rx are the same, the soft toric CL is under-correcting the pt’s astig; thus, the cyl power in the soft toric CL should be increased.
If the axis of the OR is 090 away then subtract the OR from the pts astig
If the axis of the OR and spec Rx are oblique, the axis of the soft toric CL is incorrect or the CL rotated on the eye
All of the following may occur as a result of an aneurysm of the posterior communicating artery EXCEPT:
a. impaired accommodation
b. Limited abduction
c. Limited supraduction
d. Mydriasis
e. Ptosis
b. Limited abduction
A PCA aneurysm is the MOST common cause of a pupil-involved CN3 palsy.
Impaired CN3 innervation results in Mydriasis (impaired iris sphincter), Ptosis (impaired levator), Poor accommodation (impaired ciliary muscle), & limited adduction, supraduction, and infraduction (poor innervation of the MR, SR, IO, and IR)
Which of the following statements regarding visual development is INCORRECT?
a. Accommodation & fusional vergence are present at birth
b. Saccades are hypometric until ~6 years of age
c. Stereopsis reaches adult levels at 6 months of age
d. Near point of convergence is NOT detectable until 6 months of age
a. Accommodation & fusional vergence are present at birth
NOTE: accommodation & fusional vergence do NOT develop ~1 month after birth
A 53 year old female complains of spontaneous, intermittent, involuntary, bilateral, transient eyelid closure that most commonly occurs while reading or following exposure to bright lights. You detect adequate lid symmetry and good lid position, and all CNs are fully intact. The pt has no dysdiadochokinesia w rapid alternating movements & demonstrates a well-balanced & coordinated gait. What is the MOST likely Dx?
Benign essential blepharospasm
NOTE: characterized by idiopathic bilateral lid closure causing transient blindness until the spasm resolves
Which of the following ganglia provides parasympathetic innervation to the lacrimal gland to stimulate aqueous secretion?
Pterygopalatine!
NOTE: parasympathetic innervation travels w the greater petrosal nerve of CN7 –> Postganglionic parasympathetic fibers join the zygomatic branch of V2 before joining the lacrimal nerve of V1 to innervate the lacrimal gland
Which of the following is an example of an anastomosis btwn the internal and external carotid arteries that supply ocular structures?
a. The infraorbital artery joins the facial artery to supply the lower eyelid and lacrimal sac
b. The angular artery communicates with the dorsal nasal artery to supply the medial canthus
c. the superficial temporal artery communicates w the facial artery to supply the superficial skin around the orbit
d. the dorsal nasal artery communicates w the supratrochlear artery to supply the lacrimal sac
b. The angular artery communicates with the dorsal nasal artery to supply the medial canthus
The angular artery (from the facial artery of the ECA) communicates w the dorsal nasal artery (from the OA of the ICA) and supplies blood to the medial canthus
The infraorbital artery (from the maxillary artery of the ECA) joins w the dorsal nasal artery (from the OA of the ICA) to supply the lower eyelid and the lacrimal sac
The superficial temporal artery from the ECA communicates w branches of the OA from the ICA
The Supratrochlear artery does NOT communicate with branches of the ECA
A choroidal melanoma is characterized by abnormal proliferation of melanocytes within which of the following layers?
Choroidal stroma
RECALL: Choroidal melanomas are the MOST COMMON primary intraocular malignancies in adults.
Light absorption by a PR results in what?
Closure of Na+ channels
Hyperpolarization of the cell
DEC glutamate release
PR responds with graded potentials
UV exposure to cells in the stratum basale of the eyelid is MOST likely associated w which of the following clinical findings?
Telangiectasia
NOTE: damage to stratum basale of the eyelid results in the development of BCC. Recall that a key characteristic that DDx BCC from Squamous cell carcinomas (located w/in the stratum spinosum) is the presence of surface telangiectasia
What is the physiological limit of VA in a theoretical human eye with perfect optics?
20/8
This is due to the cone diameter
Your pt’s palpebral fissure OD appears wider vertically compared to OS due to trauma. His right eye is non-seeing. The pt desires a spectacle lens OD that will cosmetically equalize (narrow) the appearance of his right eye in the vertical meridian only. What is the power of the right lens that would BEST address this pt’s request?
a. +1.00-1.00x180
b. +1.00-1.00x090
c. plano-2.00x180
d. plano-2.00x090
c. plano-2.00x180
Trying to minimize vertical meridian
What are associated with idiopathic intracranial HTN?
Oral contraceptives, tetracyclines, Accutane, vitamin A, and Naladixic acid (a quinolone antibiotic)
what test should be performed in order to determine the etiology of CME?
FA!
Irvine Gass will leak
A CR-39 spec lens has a back vertex power of +4.00D. If the lens has a center thickness of 3mm & is worn at a vertex distance of 10mm, the power mag produced by the lens is approx what?
1.05X
1/(1-h*Fv)
h=10mm+3mm (distance from cornea to EP)
1.05X means 5% magnification due to the lens
What is the greatest risk for developing a macular hole
Increasing age
A pt with a Hx of an intracranial mass has an impaired optokinetic nystagmus response when the drum is rotated to the RIGHT. Where is the MOST likely location of the lesion?
Right Parietal Lobe
Recall: Parietal lobe lesions can affect pursuits and therefore the OKN response. A parietal lobe lesion will inhibit pursuit movements on the same (ipsilateral) side of the lesion. When a OKN drum is spun to the right, the resultant eye movement in a normal pt will be tracking movement (smooth pursuit) to the right followed by a refixation (saccade) to the left. In this case, since the OKN response is impaired w the drum spinning ot the right, the right parietal lobe must be the area involved
A pt presents w retinal hemorrhages and bilateral temporal optic nerve pallor on dilated fundus exam. Which of the following types of anemia is the MOST likely cause of these ocular findings?
Pernicious
NOTE: pernicious anemia is caused by autoantibodies directed against parietal cells in the stomach, resulting in DEC production of intrinsic factor necessary for the absorption of vit B12. Inadequate intake of vit B12 is associated w retinal hemorrhages & temporal optic nerve pallor
A 35 year old male presents w bilateral, yellow, elevated, plaque lesions within the upper medial portion of the eyelids. Which of the following tests is MOST appropriate?
Triglycerides, HDL, and LDL
You devise a new test to determine whether pt has glaucoma. To determine the sensitivity and specificity of your test, you administer it to 100 pts who are known to have glaucoma and 100 pts who are healthy. Out of the 100 pts who have glaucoma, the test gives 96 positive results and 4 negative results. Out of the 100 pts who do not have glaucoma, the test gives 25 positive results and 75 negative results. What is the sensitivity and specificity of your new test?
96% sensitive
75% specific
All of the following respiratory disease are characterized by a normal to elevated FEV1/FVC ratio EXCEPT:
a. Toxoplasmosis
b. Histoplasmosis
c. Sarcoidosis
d. Chronic bronchitis
d. Chronic bronchitis
NOTE: the FEV1/FVC ratio measures how much air a pt can forcefully expire in one second vs total forced lung capacity. A normal to elevated FEV1/FVC ratio is characteristic of restrictive lung diseases (i.e. sarcoid, toxoplasmosis, and histoplasmosis). Chronic bronchitis is an obstructive lung disease that is characterized by a reduction in the FEV1/FVC ratio
<80% ratio indicates obstructive lung disease
If the trigeminothalamic pathway is severed at the level of the medulla, what would happen MOST likely?
a. Proprioception
b. Taste
c. Light touch from contra side of face
d. Pain from ipsi side of face
d. Pain from ipsi side of face
NOTE: trigeminothalamic pathway carries pain and temperature info from face. Fibers enter brainstem at pons, descend to the spinal nucleus of CNV at the level of the medulla, and then decussate to ascend to the thalamus. Thus, a lesion at the medulla will result in loss of pain info on the ipsi side of the face
Which of the following ocular striated muscles is the last to develop?
a. Superior oblique
b. Inferior rectus
c. Superior rectus
d. Levator palpebrae
d. Levator palpebrae
The levator palpebrae is the last muscle to appear as it splits from the superior rectus during development. Recall that the orbital striated muscles are derived from mesodermal mesenchyme that differentiates into myoblasts
How do interferons provide resistance against corneal epithelial dendritic keratitis?
They prevent the replication and production of new viruses within neighboring cells
Recall that interferons are polypeptides produced by viral-infected cells that help to protect neighboring cells from viral infections. Although viruses can still penetrate neighboring cells, interferons prevent viral replication and the production of new virus particles
A pt w a TBI to the LEFT FRONTAL LOBE will MOST likely show DEC function when making saccades in which direction?
To the Right Side
NOTE: saccadic eye movements are generated by contralateral FEF (as well as the superior colliculus). Thus, damage to the left frontal lobe is MOST likely to affect saccades to the RIGHT side
Topical ophthalmic PG analogs INC aqueous humor outflow through (SELECT 3):
a. Vortex veins
b. Anterior ciliary veins
c. Aqueous veins of Ascher
d. Schlemm’s canal
e. Ciliary Muscle fiber bundles
a. Vortex veins
b. Anterior ciliary veins
e. Ciliary Muscle fiber bundles
Topical ophthalmic PG analogs INC aq humor outflow through the uveoscleral meshwork.
Recall the aq humor that drains through the uveoscleral meshwork passes through ciliary muscle fiber bundles to the suprachoroidal space and sclera, or drains into the anterior ciliary veins or vortex veins. Aqueous humor drains through the corneoscleral meshwork through schlemm’s canal. The aq veins of ascher (ext collector channels) then carry aq humor to the episcleral venous plexus
NOTE: PG analogs also act on skin receptors activating phospholipase C to alter hair follicles
Diabetic macular nonperfusion may result from loss of pericytes from which of the following?
a. LPCA
b. Haller’s layer
c. Sattler’s layer
d. Choriocapillaris
d. Choriocapillaris
A pt presents w symptoms of amaurosis fugax and a Hollenhorst plaque OD. All of the following tests are indicated EXCEPT:
a. CT scan
b. Echocardiogram
c. Carotid ultrasound
d. FA
d. FA
Pts w retinal embolia and/or amaurosis fugax are at a greater risk of development of TIAs and/or strokes. They should be referred immediately for a CT or MRI to determine whether a concomitant stroke is occuring. A carotid ultrasound and cardiac studies (i.e. EKG, echocardiogram) are also warranted to determine the source of the embolus.
Which of the following definitions BEST describes radiant intensity?
a. The amount of energy per second produced by a light source
b. The amount of energy per second in a specific direction (or amount of space) produced by a light source
c. The visual system’s response to a given amount of energy per second produced by a light source
d. The visual system’s response to a given amount of energy per second in a specifc direction (or amount of space) produced by a light source
b. The amount of energy per second in a specific direction (or amount of space) produced by a light source
a is radiant power
c is luminance power
d is luminance intensity
Which of the following statements regarding visual development of the infant is FALSE?
a. aprox half of the changes necessary for development of the adult eye occur within the first 6 months
b. The sclera in an infant is approx half the thickness of the sclera in an adult
c. A newborn has the same average IOP as an adult
d. The lacrimal system is patent at birth but does not reach full development until 3-4 years
c. A newborn has the same average IOP as an adult
The avg IOP of an infant is 10 mmHg and increases 1mmHg per year until the age of 5.
The avg scleral thickness in an infant is 0.45mm vs 1.09 mm in an adult
The lacrimal system is normally fully patent at birth, although 2-4% of neonates have an obstruction of the nasolacrimal system. It is not fully developed until 3-4 years of age
Which of the following enzymes is inhibited by 1% trifluridine, prescribed for a patient with herpes simplex epi keratitis?
DNA polymerase
1% trifluridine (viroptic) is a topical ophthalmic antiviral medication that inhibits the replication of herpes simplex virus within corneal epi cells by inhibiting DNA polymerase. Recall that DNA polymerase is the enzyme responsible for extending the new DNA strand during replication
What drug properties is the best at corneal penetration?
Hydrophilic and lipophilic properties
NOTE: hardest is hydrophilic molecules
A 31 year old pt presents w multiple molluscum contagiosum lesions bilaterally on his eyelids. What is the MOST appropriate test you should order to further eval this pt?
ELISA
NOTE: molluscum contagiosum lesions are caused by DNA poxvirus. It is a self-limiting condition that typically resolves 2-3 months after onset. It most commonly occurs in children or in adults as a single or few lesions. Adults who preent w multiple lesions should be evaluated for an underlying immunosuppressive condition, including HIV.
ELISA is the most appropriate test to order in cases of suspected HIV
FTA-ABS and RPR test = syph
CBC w diff = non specific usually to see if an infection, inflammation, bone marrow disorder, or autoimmune disease
How does Fuch’s heterochromic iridocyclitis affect bluer and browner eyes?
Bluer eyes become DARKER
Browner eyes become LIGHTER
NOTE: FHI is uni iridocyclitis that presents w minimal pain and redness & rarely presents with PAS/PS
The terminal complex btwn RPE cells contain all of the cell junctions EXCEPT:
a. Zonula adherens
b. Hemidesmosomes
c. Macula adherens
d. Zonula occludens
b. Hemidesmosomes
NOTE: terminal complex btwn RPE cells that forms the BRB is composed of ZO, ZA, & MA. Hemidesmosomes connect an epi layer w its underlying basement membrane
A pt presents w Rx -2.00-2.00X150. Which line will appear MOST blurred on clock dial test when pt is uncorrected?
2-8 o’clock
Decreased levels of the enzyme citrate synthase will MOST likely result in the INC production of all of the following EXCEPT:
a. Acetoacetate
b. Acetone
c. Beta-hydroxybutyrate
d. ATP
d. ATP
Citrate synthase is responsible for converting acetyl CoA into citric acid, which is the 1st step in Kreb;s cycle. If citrate synthase is NO longer available, acetyl CoA is shuttled away from the Krebs cycle & is used to produce ketone bodies (acetone, acetoacetate, and beta-hydroxybutyrate). Recall that ketone bodies are primarily produced during starving conditions.
How does the body compensate for blood acidity changes from hypoventilation?
a. DEC excretion of HCO3-
b. DEC excretion of H+
c. INC excretion of HCO3-
d. INC excretion of H+
a. DEC excretion of HCO3-
What infectious entity is MOST commonly implicated in the development of acute retinal necrosis syndrome (ARN)?
Varicella zoster
NOTE: ARN is most commonly attributed to members of the herpes virus family, predominantly varicella zoster and herpes simplex.
A serous retinal detachment is associated w all of the following EXCEPT:
a. Posterior scleritis
b. Proliferative vitreoretinopathy
c. Optic pit
d. Intraocular neoplasm
b. Proliferative vitreoretinopathy
Which of the following oral NSAID is MOST appropriate in pts w peptic ulcer Dz?
a. Naproxen
b. Ibuprofen
c. Celecoxib
d. Indomethacin
c. Celecoxib
Celecoxib is a selective COX2 inhibitor
COX2 prevents production of inflammatory PG w minimal effects on PG produced physiologically. COX2 inhibitors are therefore MOST appropriate in pts w peptic ulcer Dz bc it will have minimal impact on the synthesis of PG that protect the gastric mucosa. The other choices exacerbate peptic ulcers
INC water content in a traditional hydrogel contact lens results in which of the following?
a. Better handling
b. Improved VA
c. DEC depositing
d. Greater stability
a. Better handling
INC water content in a traditional hydrogel CL results in better handling bc inc water leads to inc in CL thickness.
DEC water content in a traditional hydrogel CL results in greater stability (a thinner CL will move less on eye), improved VA (due to better optics), and DEC deposits on the CL surface
Deposits are more likely to be in which FDA classification of SCL?
Group 4: HIGH water content, ionic
Which of the following are contraindications of oral CAIs such as acetazolamide (select 3)?
a. Post op cataract care
b. Systemic HTN
c. Pregnancy
d. Tachycardia
e. Liver disease
f. Severe COPD
g. Cough
c. Pregnancy
e. Liver disease
f. Severe COPD
Acetazolamide should be avoided in pts w severe COPD bc these pts may be unable to inc their alveolar ventilation enough to compensate for the acid-base alterations induced by the drug. Further, alkalinization of urine may result in INC levels of ammonia in the systemic circulation, contributing to the development of hepatic encephalopathy. Thus, acetazolamide is CI in pts w clinically sig liver disease. It is also CI during preg. Post op cat care & tachycardia are not CI; acetazolamide lowers BP & is therefore a benefit in pts w systemic HTN
Which of the following statements regarding retinopathy of prematurity (ROP) are CORRECT? select 3
a. Screenings for ROP should be performed at the hospital after birth for all babies who weight less than 2000 grams
b. Pts w ROP may present w a “dragged” appearance of the macula
c. Unlike infants born at a normal birth weight, infants w ROP demonstrate an incomplete development of the macula at birth
d. Incomplete development of the macula at birth
e. INC O2 exposure immediately after birth leads to an INC risk of development ROP
f. ROP may be assocaited w the development of high myopia in infants
b. Pts w ROP may present w a “dragged” appearance of the macula
e. INC O2 exposure immediately after birth leads to an INC risk of development ROP
f. ROP may be assocaited w the development of high myopia in infants
Screenings for ROP are performed in infants who weight < 1500 grams at birth, as they have the higher risk for development of ROP. The development of the macula is incomplete at birth in all infants, not just those who develop ROP. The macula continues to mature through 4 years of age.
Which entopic phenomenon should be MOST concerning to a clinician?
a. Phsophenes
b. Blue arcs of the retina
c. Purkinje tree
d. Moore’s lightning streaks
d. Moore’s lightning streaks
Moore’s lightning streaks are vertical flashes of light seen in the periphery of the visual field. They are associated w viterous syneresis and retinal distention (tugging on the retina) and can be a harbinger of retinal breaks or detachments.
Purkinje tree is a normal phenomenon that involves the visualization of the retinal vasculature as moving light casts shadows on the retina
Phosphenes are flashes of light that are a result of neural noise or mechanical (i.e. rubbing one’s eyes) or electrical stimulation of the retina (almost NEVER a sign of peripheral retinal issues)
Blue arcs of the retina originate from a light source and extend towards the physiological blind spot. Perceived when viewing a dim light in a dark room
Which of the following serum lab results is Dx of acute pancreatitis?
Elevated lipase
The pancreas is responsible for releasing enzymes into the intestine for digestion, including lipase and amylase. Pancreatitis results in a DEC in the release of lipase and amylase into the digestive tract causing an increase in blood serum levels.
What does the blur point represent in a pt who is being tested for negative fusional vergence at 6pd?
Convergence-induced accommodation has decreased and the pt is no longer able to increase blur-induced accommodation to keep the target clear; the pt’s hyperopia is under-corrected
NOTE: blur point is not expected when testing NFV ranges at distance bc accomm should be fully relaxed. however, if a pt does report a blur point at far, the pts accomm was not fully relaxed at the beginning of the test, indicating too little plus (or too much minus) in the distance rx
Which of the following characteristics of the corneal stroma contributes to corneal transparency?
a. there is less cross-linking and less branching of collagen fibers in the posterior 2/3 of the cornea
b. The anterior 1/3 of the stroma has a high degree of cross-linking btwn collagen fibers
c. Glycosaminoglycans within the stroma repulse water to maintain corneal transparency
d. Collagen lamellae within the stroma are uniformly spaced
d. Collagen lamellae within the stroma are uniformly spaced
NOTE: uniform spacing of type 1 collagen lamellae is essential in order to maintain corneal transparency. Glycoaminoglycans attract water and help maintain the precis spacing of the collagen lamelle. The degree of cross-linking and branching of collagen fibers in the ant compared to the post stroma contributes to corneal rigidity and curvature more so than corneal transparency
Which of the following statements regarding the conjunctiva is INCORRECT?
a. The conj moves in conjunction w the eye bc the forniceal conj is attached to the fascia surrounding the EOM
b. The marginal conj is continuous w the epi of the skin at the mucocutaneous junction of the lid
c. The submucosa of the bulbar conj is loosely attached to Tenon’s capsule until approx 3 mm from the cornea
d. The submucosa of the tarsal conj is thin and loosely attached to the tarsal plate
d. The submucosa of the tarsal conj is thin and loosely attached to the tarsal plate
FALSE
The submucosa of the tarsal conj is THICKER compared to the marginal conj bc it contains the accessory lac glands. It is tightly linked tot he underlying tarsal plate of the upper eyelid. The remaining statements regarding the conj are correct.
What is the gain of the VOR approximately?
1:1
VOR functions to keep eyes aligned w an object during head movement. The gain is the ratio of eye movement to head movement. Thus, the gain must be 1:1 (i.e. 5 degrees of eye movement for 5 degrees of head movement) in order to keep the eyes aligned on the image
A 45 year old female presents w 2+ superior bulbar conj injection that stains w lissamine green and NaFl, small superior bulbar conj papillae, and superior superficial punctate keratitis OU. What is the MOST likely Dx?
Superior limbic keratoconjunctivitis
Which of the following conditions is MOST likely to result in permanent loss of vision?
a. Atopic keratoconjunctivitis
b. Perennial allergic conjunctivitis
c. Seasonal allergic conjunctivitis
d. Vernal keratoconjunctivitis
a. Atopic keratoconjunctivitis
Atopic keratoconjunctivitis may cause corneal epi erosions, corneal neo & opacification, conj scarring, & symblepharon formation, resulting in permanent DEC vision
Oral propranolol should be prescribed w caution in pts w which of the following systemic conditions (select 3)?
a. Insulin-dependent DM
b. POAG
c. COPD
d. Bronchil asthma
e. Cardiac arrhythmias
a. Insulin-dependent DM
c. COPD
d. Bronchil asthma
NOTE: propranolol is a nonselective Beta-receptor antagonist. It has negligible effects on alpha receptors and muscarinic receptors. Inhibition of beta-2 in lungs leads to bronchoconstriction; thus, propranolol should be used w caution in pts w COPD and asthma.
Propranolol may also result in hypoglycemia & should be prescribed w caution in pts w insulin-dependent DM. Selective Beta-1 receptor antagonists are safer alternatives to propranolol for pts w these systemic conditions.
Which of the following oral medications may cause aplastic anemia (SELECT 3)?
a. Acetazolamide
b. Furosemide
c. Chlorpheniramine
d. Cephalexin
e. Trimethoprim
f. Chloramphenicol
a. Acetazolamide
e. Trimethoprim
f. Chloramphenicol (fatal + optic neuritis)
Aplastic anemia is a fatal condition secondary to bone marrow suppression; it is characterized by insufficient production of new blood cells
NOTE: methotrexate also causes
Which of the following statements regarding the clinical properties of the topical ophthalmic combination agent brinzolamide/brimonidine is TRUE?
a. the FDA-approved dosing frequency is BID
b. This medication is the only combination agent for the Tx of elevated IOP that does NOT contain an adrenergic antagonist
c. This medication should be avoided in pts w asthma or COPD
d. This medication is less effective than either of its components used singly or in combination
b. This medication is the only combination agent for the Tx of elevated IOP that does NOT contain an adrenergic antagonist
A lesion that impacts only the parvocellular pathway would have the MOST effect on what?
Ability to discern colors in isoluminant gratings
NOTE: the magnocellular pathway processes and transmits the majority of high-frequency flickering stimuli, low spatial frequency stimuli, and stimuli that move at high velocities. Conversely, the parvocellular pathway processes and transmits the majority of wavelength-based discrimination (color vision) & high spatial frequency stimuli (VA).
Isoluminant gratings are gratings that consist of diff wavelengths w the same luminance. If each grating had a diff luminance, the magnocellular pathway would be able to differentiate the wavelengths based on perceived brightness of the diff bars as determined by the photopic luminance function.
Which of the following statements regarding metamers is INCORRECT?
a. Metamer theory applies to dichromats but not trichromats
b. They are visual stimuli that are physically diff but result is identical visual perception
c. INC the intensity of the two metamers will change both metamers, , but they will still appear identical
d. Adding light of the same wavelength and radiance to two metamers will change both metamers, but they will still appear identical
a. Metamer theory applies to dichromats but not trichromats
Metamer theory is based on the principle of uvariance: the wavelength of a given light determines how many photons are absorbed by the visual system, but once the photon is absorbed, all info about wavelength is lost. the implication is that the visual system can be confused. we can create metamers by mixing diff wavelengths to make them appear identical. Grassman’s law tell us that we can make certain changes to metamers and they will still appear identical. One of grassman’s laws staes that adding light of the same wavelength and radiance to two metamers will result in an identical change in both metamers. Another of grassman’s laws states that increasing the intensity of two metamers will result in an identical change in both metamers. Metamer theory applies to trichromates and dichromats.
A clinician performs NPC testing on a pt who is wearing their habitual correction. Which of the following vergence eye movements made by the pt has the LEAST contribution in NPC testing?
a. Proximal
b. Accommodative
c. Fusional
d. Tonic
a. Proximal
Its present but clinically negligible
The PR dark current is characterized by all of the following EXCEPT?
a. Resting membrane potential is more negative than other cells
b. Higher outer segment membrane permeability to Na+ ions
c. Net flow of cations into the outer segment and out of the inner segment
d. High outer segment membrane permeability to Ca2+ ions
a. Resting membrane potential is more negative than other cells
The PR dark current is characterized by net flow of cations into the outer segment and out of the inner segment. This is accomplished by the CNG (i.e. phototransduction) channel, which increases outer segment permeability to Na_ and Ca2_, resulting in a less (-) resting membrane potential
Increased tension on the scleral spur PRIMARILY results in which of the following?
INC in corneoscleral outflow
NOTE: scleral sput is the point of attachment for the ciliary muscle longitudinal fibers and the lamellae of the TM. Ciliary muscle contraction INC tension and pulls the scleral spur posteriorly, resulting in an increase in the size of the pores of the TM & an INC in corneoscleral outflow
A 47 year old male presents w an iris OD that is sig lighter in color than the iris OS. You note stellate keratic precipitates, trace cells in the AC, and a sig posterior subcapsular cataract OD. His IOP are 32 mmHg OD and 16 mmHg OS. What is his Dx most likely?
Fuchs’ Heterochromatic Iridocyclitis
FHI is characterized by a chronic low grade anterior chamber inflammation that leads to the development of iris heterochromia, stellate keratic precipitates, PSC, and elevated IOP
Pt presents w peripheral corneal ulcer and associated anterior necrotizing scleritis. What is the MOST likely cause of this pt’s peripheral ulcerative keratitis?
Collagen vascular disease
Peripheral ulcerative keratitis, particularly in combination w scleritis, carries a high risk of an underlying, often undiagnosed, collagen vascular disease or systemic vasculitis
Topically administered ophthalmic cyclopentolate may cause systemic adverse effects in low birth weight infants. Which of the following is NOT a possible ADE?
a. Inhibition of gastric secretion
b. Hyperglycemia
c. INC Heart reat
d. Elevated BP
b. Hyperglycemia
Trop alone does not produce sufficient mydriasis in premature infants.
True or false. The topical form of Besifloxacin medication was derived from systemic formulations.
False!
When is edge clearance the lowest?
The peripheral curve radius is steep in combination with the smallest width. In this case, the 10.4mm radius, in combo w 0.2mm width, would represent the lowest or least edge clearance design
Which ophthalmic drugs do NOT provide rapid relief of ocular itching?
a. Lodoxamide
b. Emedastine
c. Epinastine
d. Olopatadine
a. Lodoxamide
NOTE: lodoxamide is a mastc ell stabilizer that prevents mast cell degranulation and the release of allergic mediators (i.e. histamine). It is ineffective at treating acute ocular allergy symptoms bc it cannot reverse the effects of histamine that has already been released by degranulated mast cells. Emedastine is a selective H1 receptor antagonist that prevents histamine from binding to its receptors; this, it is indicated for hte rapid relief of ocular itching. Epinastine and olopatadine are dual acting mast cell stabilizer and antihistamines and are indicated for both immediate and long-term Tx of ocular allergies
All of the following are CI to the admin of topical ophthalmic pilocarpine EXCEPT:
a. Hx of RD
b. Absolute presbyopia
c. Uveitic glaucoma
d. COPD
b. Absolute presbyopia
All of the following topical ophthalmic medications are indicated for the Tx of fungal keratitis EXCEPT:
a. Amphotericin B
b. Natamycin
c. Miconazole
d. Trifluridine
d. Trifluridine
Which of the following systemic medications is NOT associated w NAION?
a. Sumatriptan
b. Sildenafil
c. Amiodarone
d. Prednisone
v
Prednisone has not been linked to NAION. The remaining are associated. Sumatriptan is selective serotonin agonist that is used in the Tx of migraines. Sildenafil is a PDE-5 inhibitor used in the Tx of ED. Amiodarone is indicated for tps w cardiac arrhythmias
Which of the following 2 statements regarding the Developmental Test of Visual Motor Integration are CORRECT? (select 2)
a. Partial credit may be given when the pt meets 2/3 criteria for a given response
b. Pts are allowed to erase and correct their drawings
c. The test should be stopped after a pt misses 3 consecutive examples
d. The pt’s drawings are graded based on specific criteria that involve measuring the angles and the length of the figures
e. The pt is asked to trace drawings in pencil during the test.
c. The test should be stopped after a pt misses 3 consecutive examples
d. The pt’s drawings are graded based on specific criteria that involve measuring the angles and the length of the figures
