EPT3 Flashcards
Which of the following statements regarding migraines without auras is FALSE?
a. Neuro-imaging should be performed if patients have an initial episodes after the age of 50
b. They develop due to abnormal dilation of blood vessels within the brain
c. They are known as classic migraines
d. They are associated with normal tension glaucoma
c. They are known as classic migraines (FALSE)
Migraines without aura are called common migraines; migraines w auras are known as classic migraines and are less common than migraines without auras. Evidence suggests that migraines are associated with NTG, as they are due to poor regulation of BF, which is thought to play a role in the development of optic neuropathy in NTG. Bc it is rare for an initial migraine episode to occur after the age of 50, neuro-imaging is advised in pts who have an initial migraine episode after the 5th decade of life.
What level of VA is expected for a 6 month old when tested with forced preferential looking cards?
20/100
NOTE: although infants can achieve 20/20 VA by 6 months of age w VEPs, spatial VA does NOT reach 20/20 levels until approx 3-4 years of age. Spatial VA using forced preferential looking cards is ~20/600 to 20/1200 by `1 month of age, and 20/50 to 20/60 by 1 year og age
What is the MOST common cause of spontaneous vitreous hemorrhage in adult patients?
Proliferative diabetic retinopathy
NOTE: PDR is the MOST common cause of spontaneous vitreous hemorrhage in adults (30-50% of cases). Followed by retinal breaks/retinal vein occlusions. Acute PVD may also result in a vitreous hemorrhage, but in a much smaller % of cases compared to the other 3 options
What procedure involved surgically removing the corneal tissue down to Descemet’s membrane?
Deep anterior lamellar keratoplasty (DALK)
Where is a lamellar cataract located?
Between nuclear and cortical layers of the lens - may be acquired from tetany or rickets early in life
A persistent pupillary membrane is due to incomplete regression of what during development?
The Tunic Vasculosa Lentis
Which Purkinje images is a real and inverted image?
IV
NOTE: I: front surface cornea II: back surface of cornea III: front surface of crystalline lens IV: back surface of crystalline lens - also only concave MIRROR surface which produce Real Inverted Images, Virtual upright images or no image at all
For plus lenses, how do you increase spectacle magnification with vertex distance, spectacle lens thickness, base curve, and index of refraction in the myopic (minus lens) to reduce aniseikonia?
Vertex distance: INC
Spectacle Lens thickness: INC
Base Curve: INC
Index of Refraction: DEC
RECALL:
Ms = 1/[1-(t/n)F1’
Mp=1/[1-hFv’]
For minus lenses, how do you increase spectacle magnification with vertex distance, spectacle lens thickness, base curve, and index of refraction in the hyperopic (plus lens) to reduce aniseikonia?
Vertex Distance: DEC***
Spectacle Lens Thickness: INC
Base Curve: INC
Index of Refraction: DEC
Which of the following is found in a high concentration in mature lens fibers?
a. collagen
b. fibroblasts
c. Cystallins
d. hyaluronic acid
c. Crystallins
NOTE: alpha crystallins act as chaperones to reverse degradation of other crystallins. No collagen or fibroblasts within the lens. HA is present within the vitreous rather than lens
What is the predominant mechanism responsible for INC IOP in pts who are “steroid responders”?
DEC outflow facility
NOTE: not fully understood, the prevailing mechanism for an INC in IOP secondary to steroid use is that steroids INC deposition of glycoasminoglycans in the TM, resulting in reduced aqueous humor outflow
When does the critical period of visual develop extend from?
Birth to 9 years
NOTE: the critical period of development of the visual cortex is from birth to 7-9 years of age. The first 2-3 years of life are considered the most sensitive for development of the visual cortex
A frame has the dimensions 46-19-140 with an ED of 50 mm. The pt’s PD is 69 mm. What is the minimum lens blank size?
56 mm
MBL = ED + |(Frame PD - Pt PD)| + 2mm
A barber reclines his client’s chair toward a sink to wash his hair. When the barber turns on the water, it is very warm and gets into the client’s left ear. If the client has a normal response, the slow phase of the induced nystagmus will be in what direction?
RIGHT
A nystagmus is direction of the fast phase. In a normal, caloric testing with warm water in left ear will induce a left horizontal nystagmus, meaning the slow phase will be to the right.
What is the primary excitatory NT in the retina?
Glutamate
The protein lactoferrin is an important component of the secretions from where?
Lacrimal gland
Lactoferrin chelates Fe2+, preventing growth and metabolism of bacterial cells
A 43 year old male presents w trace AC reaction, an IOP of 48 mmHg, and an open angle on gonioscopy OD. What is the most likely cause of the uveitis?
Posner-Schlossman syndrome
AKA glaucomatocyclitic crisis, characterized by a very mild AC rxn w IOP elevated in the presence of an open angle of gonioscopy. Pts are often asymptomatic unless IOP is acutely elevated.
What is the near pupillary response mediated by?
Frontal eye fields which provide input to the EW nucleus
What is the light response mediated by?
Tectotegmental tract (includes pretectal nuclei that sends info to both EW nuclei)
What are the effects of systemic adrenergic agonists?
INC effects of sympathetic nervous system –> results in tachycardia (INC heart rate)
Bronchodilation
DEC gastric secretions
Vasoconstriction
Mydriasis
NOTE: miosis, bronchoconstriction, & INC gastric secretions are PNS
A photoreceptor hyperpolarized by light will _____ glutamate release, causing an __-bipolar cell to release more ___.
DECREASE glutamate release
ON-bipolar cell
Release more GLUTAMATE
NOTE: on-center bipolar cells are inhibited by glutamate and will therefore hyperpolarize in the dark. Under light conditions, the PR will hyperpolarize, resulting in a DEC of glutamate, which will cause the on-center bipolar cells to depolarize & release MORE glutamate to act on the ganglion cells
Which of the following meds cause bronchodilation?
a. Muscarinic receptor agonist
b. B-1 receptor agonist
c. Nicotinic receptor agonist
d. B-2 receptor agonist
d. B2 receptor agonists
NOTE: B2 receptors are located on the bronchioles & are stimulated by NT of the SNS. INC SNS –> INC bronchodilation (f/f).
Which is NOT a potential systemic ADE of topical ophthalmic B-adrenergic receptor ANTAGONISTS?
a. Wheezing
b. Depression
c. INC heart rate
d. Weakness
c. INC heart rate (is FALSE)
Antagonism of B-adrenergic receptors lead to DEC in SNS activity & is characterized by bronchospasm (causing wheezing or shortness of breath), bradycardia, & CNS effects (depression/sexual dysfunction/weakness/memory loss/lethargy)
Which inflammatory cell is the first to arrive in large numbers at the site of injured tissue in acute inflammation?
Neutrophils
NOTE: acute inflammation is characterized by the migration of neutrophils from circulation to the site of tissue injury within 1-2 minutes following initial injury. Chronic inflammation is characterized by infiltration of macrophages, lymphocytes, & plasma cells
An embolus originating as a thrombus in the ICA MOST commonly occludes a BV in the…?
Retina
NOTE: CRA (supplies INL/IPL/OPL) branches from OA, which is a branch of the ICA. Thus, an embolus originating from a thrombus within the ICA is most likely to travel to the retinal vasculature
Distance PD of 68mm wears a frame with an eye size of 43 mm and a DBL of 17 mm. How much should each lens be decentered in order to avoid induced prism?
68-(43+17)=8/2=4 mm out
Bilateral intraocular inflammation following a unilateral globe penetrating wound is?
Sympathetic ophthalmia
What is true about Cl- and Na+ in corneal deturgescence?
Cl- excretion * Na+ absorption drive corneal dehydration
Corneal deturgescence is normal in order to preserve corneal transparency.
A patient with a lax criteria in a signal detection experiment is likely to have a very small amount of which of the following?
False negatives
Lax = “trigger happy”
Therefore, unlikely to miss any signals that are actually present, i.e. will have very small amount of FN, trade off is HIGH FP
Which layer of the cornea is PRIMARILY affected by pterygium?
Bowman’s layer
Oral antihistmainse cause which ocular ADEs?
- DEC accommodation
- DEC aqueous tear production
- INC pupil size
NOTE: anything anti-cholinergic basically
Bilateral aphakes will have all of the following in their spectacles EXCEPT:
a. Pincushion distortion
b. INC convergence at near
c. Barrel distortion
d. reduced FOV
c. Barrel distortion (FALSE) - seen in high minus lenses
Which layer of cornea is the first to become edematous under hypoxic conditions/
Epithelium
True or false. Anterior uveitis will produced hypersecretion of aqueous humor from the ciliary body?
FALSE.
Inflamed CB is less functional and produces less aqueous humor; therefore, reduced IOP however can become elevated if PS/iris bombe/angle closure form, or deposits of inflam in TM
A 10 year old pt presents w a complaint of bilateral itching of the eyelids. You note blood-tinged debris along the eyelid margins and preauricular lymphadenopathy. What is the MOST likley Dx?
Pediculosis (i.e. phthiriasis palpebrarum)
NOTE: characterized by lice infestation of eyelids, itching prominent symptom. Signs = nits (eggs) & blood-tinged debris along eyelid margins * preauricular lymphadenopathy.
