KMK Cards Book 1 Flashcards
Abnormal findings w/in NFL include:
- CWS (aka soft exudates), commonly d/t diabetes
- Splinter hemorrhages (aka Drance hemes), at or near the optic disc.
- Flame hemorrhages, associated w/ retinal vascular pathologies (diabetes, hypertensive retinopathy, retina vein occlusions)
**issues in the NFL are more superficial
Pathology found in INL
Dot or blot hemorrhages (deep retinal vascular pathology).
Astrocytes, define
Define: astrocytes are fibrous cells that provide structure to nerve fibers and retinal capillaries. Performing similar function as Muller cells.
Astrocytes replace the foot plates of Muller cells at the optic disc. This means that the internal limiting membrane (INL) is not present over the optic disc.
Define Muller Cells
Most common glial cell present exclusively in retina. Extends from ELM to the ILM. Most muller cell bodies are located within the INL. Gives structural and nutritional support.
- Maintains alignment of retina.
- provides nutrients to retina and aids in glycogen metabolism (excess glucose is converted in glycogen and stored here for the photoreceptors to use).
- Absorbs and recycles metabolic waste products such as GABA and glutamate.
Microglial cells, define
- phagocytosis cells
- responds to inflammation and/or injury
- found anywhere in retina
Central retinal artery, CRA
There are 2 capillary networks from the CRA: superficial capillary network in the NFL and a deep capillary network in the INL (near OPL).
- central retinal vein will drain inner retinal layers while the outer retinal layers will be drained by the vortex veins
Foveala, define
Last area of the retina to develop. It is completely avascular and contains only cones (no ganglion cells, bipolar or other cells).
- Retina is thickest just outside the fovea in the parafoveal region.
- Retinal layers present: RPE, photoreceptors layer, ELM, ONL, Henle’s fiber layer, and ILM.
Peripheral retina; what happens at the periphery?
- terminates approximately 5 mm anterior to the equator of the eye at the Ora Serrata. Ora Serrata is a 2 mm band at the anterior-most portion of the retina and composed of dentate processes and oral bays.
- RPE becomes pigmented ciliary epithelium
- neural retina significantly thins and transitions into the NPCE.
- Vitreous base (strongest point of attachment) extends over and posterior to the Ora Serrata.
- thinning out of the retinal vasculature
Dentate processes, define
Extensions of peripheral retina onto par plana of the ciliary body
Oral bays, define
Extensions of pars plana into the peripheral retina
which nerves carry out the gag reflex?
CN9 and CN10
Glossopharyngeal and Vagus
CN-10 (Vagus) palsy
Uvula deviates away from the lesion; palate does not elevate; patient will report hoarse voice
CN-12, hypoglossal palsy
Tongue deviates towards side of lesion
Optic nerve, define
Composed of ganglion cell bodies w/in the GCL of retina
- axons converge at the optic disc, exit the sclera at lamina cribrosa, and leave orbit via optic foramen to travel through the optic canal.
CN-2, optic nerve, destinations
- LGN: relays to primary visual cortex (V1)
- Protectal nucleus: pupil innervation
- Superior colliculus: control of saccades; contra lateral and FEF
Edinger-Westphal nucleus; define
Provides parasympathetic innervation to the ciliary and iris sphincter muscles through the ciliary ganglion.
- Edinger-Westphal is within the nucleus of CN-3 that is within the superior colliculus, which is ultimately within the midbrain.
What nuclei are CN-3 connected to?
Connected to CN 4, 6, and 8 by the medial longitudinal fasciculus (MLF).
CN-3 nuclei also receives information from the superior colliculus and the visual cortex.
How does CN-3 enter the orbit?
Through the superior orbital fissure.
Travels close to posterior communicating artery before piercing roof of the cavernous sinus. Within cavernous sinus, CN-3 receives sympathetic innervation from the internal carotid artery plexus. Then it finally goes through the superior orbital fissure after separating into superior and inferior divisions.
CN-3 superior division
- Muller’s muscle (upper eyelid)
- superior levator
- SR (which is a contra-lateral muscle)
CN-3 inferior division
- MR, IR, IO
- iris sphincter (parasympathetic, pupillary constriction)
- ciliary muscle (accommodation)
CN-3 lesion/palsy
“Down and out” eye (exotropia and hypotropia)
CN-3 palsy w/ pupil-involvement
- fixed and dilated pupil
- suspicion for aneurysm of the posterior communicating artery (most likely located at the junction between the posterior communicating artery and the internal carotid artery)
CN-3 palsy w/ pupil sparing
- most likely d/t ischemia of the small blood vessels that nourish the inner fibers of CN-3
- most likely d/t systemic condition (diabetes or hypertension)
- low chance of compressive lesion
CN-4, Trochlear nerve; connection
Connected to nuceli of CN 3, 6, and 8 via the MLF (medial longitudinal fasciculus). Also connected to superior colliculus via tectobulbar tract, which then connects to the visual cortex.
Pt w/ superior oblique palsy, d/t right trochlear nerve lesion will cause…
- left superior oblique palsy
- pt tilt head towards right
Superior oblique origin:
anatomical origin: lesser wing of sphenoid bone
Physiological origin: trochlea
V2 - Maxillary division track
- V2 travels along inferior lateral portion of the cavernous sinus before entering the foramen rotundum of the greater wing of the sphenoid.
What is the nerve supply to the lower eyelid?
Zygomaticofacial –> infraorbital –> infratrochlear nerve
The infratrochlear nerve (branching from the nasociliary nerve) provides nerve supply to the medial portion of the lower eyelid (majority) and the upper eyelid.
V2 (maxillary division): zygomatic nerve
Carries parasympathetic fibers from the pterygopalatine ganglion of CN-7 to the lacrimal nerve of V1 to stimulate lacrimation.
Where is the abducens nucleus located?
Pons
Fibers leave the nucleus between the pons and the medulla and then makes a tight bend over the petreous ridge of the temporal bone before entering the cavernous sinus.
Where does the CN-6, abducens nerve, enter and exit?
CN6 enters the orbit through superior orbital fissure and passes through the common tendinous ring before innervating the lateral rectus.
A CN-6 palsy will cause what type of deviation?
ESO deviation w/ horizontal diplopia that is most apparent at distance and may also present w/ a head turn toward the affected side.
Course of CN-7, facial
Input in the CN7 begins int he pre-central motor cortex in the frontal lobe. The fibers then descend within the corticobulbar tract to the pons, where the facial motor nucleus and superior salivatory/lacrimal nuclei are located.
- Fibers exit the nuclei of CN-7 as a main motor root and the nervous intermedium root (carries parasympathetic fibers of CN-7).
What forms the vidian nerve? (part of CN-7)
Greater petrosal nerve w/ the deep petrosal nerve.
- Greater petrosal nerve carries parasympathetic innervation to the lacrimal gland.
- Deep petrosal nerve contains post-ganglionic sympathetic fibers.
Which terminal branch of CN-7 carries taste fibers from the anterior 2/3 of the tongue and provides parasympathetic supply to the submandibular and sublingual glands?
chorda tympani nerve
The main root of CN-7 passes through the stylomastoid foramen and enters the parotid gland where it divides into 5 branches (temporal, zygomatic, buccal, mandibular, and cervical branches) to supply the muscles of facial expression.
What do the temporal and zygomatic branches innervate?
Temporal: procures, corrugated, occipital frontalis, and the orbicularis oculi.
Zygomatic: orbicularis oculi
Which nerve provides innervation to the parotid gland?
CN-9, glossopharyngeal nerve
Your patient’s right lower face is paralyzed with slight drooping of the mouth. He is still able to close his eyes and wrinkle his forehead. Where is the lesion?
Supranuclear lesion of the left side (contralateral muscles of the lower face affected).
Parasympathetic innervation to the eye originates from the midbrain (CN-3) and the pons (CN-7). What are the three major functions parasympathetic innervation plays in the eye?
- miosis (via iris sphincter, CN3)
- accommodation (ciliary muscle, CN3)
- lacrimation (lacrimal gland, CN7)
Which nerve/ganglion ultimately takes in the sensory information from LPCNs and SPCNs?
trigeminal ganglion
SPCNs: original from ciliary ganglion and carry post-ganglionic sympathetic and parasympathetic fibers to various anterior structures of the eye. They also carry sensory information from the eye back to the ciliary ganglion via the nasociliary nerve.
LPCNs: branch from nasociliary nerve of V1. Caries post-ganglionic sympathetic fibers to the eye, as well as carry sensory information from eye back to the trigeminal ganglion.
By 6 months, infants have been shown to demonstrate 20/20 visual acuity with what form of measurement?
Pattern VEP testing
Examples of forced choice preferential looking.
Teller, cardiff, & broken wheel
When is the spatial visual acuity with FCPL 20/20?
20/20 at 3-4 years
1 month: 20/600-20/1200
1 year: 20/50-20/60
Which is vergence in infant equivalent to adult levels?
By six months of age.
Temporal vision is measured by the critical flicker frequency. When does this reach adult levels in infants?
Three months of age
Which acuity takes the longest to develop?
Vernier acuity, for finely distinguishing lines. Develops at 6-8 yrs.
Define occlusional amblyopia. Examples include congential cataracts, ptosis, or corneal opacities
Aka form deprivation amblyopia. Occurs when deprivation of vision during critical period (7-9 years).
3 forms of refractive amblyopia
Anisometropic amblyopia: eye with blurred retinal image develops less.
Isometropic amblyopia: large symmetrical blurring, neither eye gets a clear image.
Meridional amblyopia: uncorrected astigmatism during critical period.
Define strabismic amblyopia
Constant, unilateral deviation of one eye compared to the other.
Alternating strabismus will not result in amblyopia. Patients will have poor stereopsis.
Common cause of a bitemporal hemianopsia?
Classically caused by a pituitary gland tumor that compresses the nasal fibers from each eye that cross at the optic chiasm.
Which VF defects do lesions anterior to the chiasm and most commonly due to glaucoma cause?
- VF defects that respect horizontal midline
Which VF defects do lesions post-chiasmal and commonly due to strokes cause?
- VF defects that respect the vertical midline
Optic nerve lesions, define.
- cause asymmetric visual field loss between the eyes
- defects typically respect the horizontal midline
- defects may be bilateral but they are NOT congruous
- an APD can occur if asymmetrical damage between the optic nerves is greater enough
- visual field defects will correspond to the location of the lesion within the retinal nerve fiber layer
Retinal lesions, define.
- causes asymmetric visual field loss between the eyes (common w/ optic nerve lesions)
- defects do not respect the horizontal or vertical midlines
- defects may be bilateral but they are not congruous
When does foveal maturation occur?
at approximately 4 years of age
The anterior lens epithelium attributes to the development of the remaining nuclei: (in the following order)
fetal nucleus, juvenile nucleus, adult nucleus, and lens cortex
When does the adult nucleus form?
Contains lens fibers that are formed from birth to sexual maturation.
When is the lens cortex formed?
Contains lens fibers formed after sexual maturation.
define induction
Induction refers to how the development of one tissue influences the development of another tissue; an example during ocular development is how optic cup formation stimulates lens development.
Which embryonic layer forms the corneal epithelium?
surface ectoderm (epithelium, lids, and glands)
- also responsible for conjunctival/eyelid epithelium, lens, meibomian, Zeis, Moll, Krause, and Wolfing glands
- also the lacrimal gland, lacrimal sac, canaliculi, nasolacrimal duct, and caruncle
Which embryonic layer contributes to the formation of the corneal stroma and endothelium?
neural crest cells
- also responsible for TM, iris and CB stroma
- also sclera, choroid, and vitreous
Haab’s striae; define
folds in Descemet’s membrane
- possibly d/t increase in IOP (congenital glaucoma)
Buphthalmos; define
A character of congenital glaucoma (same/associated w/ staphyloma). It is an enlargement of the eye prior to the age of 3 secondary to elevated IOP.
Which filter do you use when trying to visualize the retinal NFL better?
Green (red free) for retina. Enhances contrast.
Which wavelength of light has an increased association with the development of macular degeneration?
485-510 nm. Blue violet light
Define Salus sign
Indication of grade 2 hypertensive retinopathy. Deflection of retinal veins at arteriovenous crossings
Which two signs are associated with grade 3 hypertensive retinopathy?
Bonnet sign
Gunn sign
At which peaks do erythrolabe, chlorolabe, and cyanolabe absorb light?
Erythrolabe: 565nm
Chlorolabe: 535nm
Cyanolabe: 430nm
Normal arden ratio?
(Light peak)/(dark trough)
1.85 is normal, less is abnormal
Where is the rhodopsin molecule found in a rod photoreceptor?
Membrane of the outer segment
What type of action potential do bipolar, photoreceptor, and horizontal cells do?
Graded potentials, not action potentials
BPH
What is the smooth endoplasmic reticulum responsible for?
- steroid production in the adrenal cortex
- storage and breakdown of glycogen and detoxification of lipid soluble drugs
- storage and release of calcium for muscle contractions in muscle cells.
Describe direct cell to cell signaling via Gap Junctions
Gap junctions connect cytoplasm of adjacent cells and serve as a passageway for small hydrophilic molecules, ions, and metabolites to pass directly from one cell to another.
Examples include the heart and intraocular lens
Define rhodopsin
An example of a transmembrane protein that is stimulated by photons to produce a signal transduction cascade within photoreceptors.
Secondary protein made of alpha helices.
What’s the strongest chemical bond?
Covalent bonds, involving the sharing of electrons between two molecules.
List of essential amino acids.
Histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine.
Conditionally essential or semi-essential amino acids include: arginine, cysteine, glutamine, and tyrosine.
Describe AA tryptophan
Precursor for serotonin, a NT
Describe tyrosine
Amino acid derived from phenylalanine.
Precursor for dopamine, epinephrine, and norepinephrine (catecholamine neurotransmitters).
With tyrosinase (absent in albinism) becomes melanin.
Which amino acids are precursor for nucleotide synthesis?
Glycine, glutamine, and aspartate.
Define IgM
First antibody made in response to an antigen. Found primarily in blood and on the surface of immature b-cells.
Describe IgG
Most plentiful Ab in the body. Able to cross placenta.
Describe IgA
- primary antibody in excretions (tears, saliva, mucous, and breast milk)
Describe IgD
Antigen receptor on surface of mature B-cells
Describe IgE
- binds to allergens and triggers histamine release from mast cells, leading to allergy symptoms and type 1 hypersensitivity reactions
- protection against parasites.
Describe collagen
- begins with hydroxylation (cofactor Vit C) of lysine and proline residues within the polypeptide strands of procollagen.
- golgi apparatus then modifies procollagen into tropocollagen
- tropocollagen connected together through covalent bonds to form collagen fibrils
Type 1 collagen
Found in cornea, sclera, and Bowmans membrane.
Osteogenesis imperfecta is an AD defect in the production of type 1 collagen. Resulting in multiple fractures, poor wound healing, hearing loss, and blue sclera.
Type 2 collagen
Found in vitreous.
Type 4 collagen
Found in descemets membrane
Type 5 collagen
Found in cornea, maintains uniformity
Diseases effecting collagen
- systemic lupus erythematoses and rheumatoid arthritis: autoimmune disorders where body attacks healthy collagen fibers.
- ehlers-danlos syndrome: abnormal type 1 & 3 collage. Resulting in loose and hyperextended joints, hyperelastic skin, aortic dissection, blue sclera and corneal thinning
- osteoporosis: decreased levels with aging
Vitamin B1 and deficiency
Thiamine
Disorder d/t deficiency: beriberi, causing peripheral nerve damage (delirium, memory loss, oculomotor paralysis, and heart failure).
Vitamin B2
Riboflavin
Define angular cheilitis
Cracking of skin and corners of mouth, can be caused by riboflavin deficiency
Vitamin B3
Niacin, can be derived from tryptophan
Define pellagra
Can be caused by chronic niacin deficiency. Symptoms: diarrhea, dermatitis, and dementia
Vitamin B6
Pyridoxine
Vitamin B12
Cobalamin
Most common deficiency worldwide, seen often with alcoholism.
Pernicious anemia
An autoimmune disorder that destroys the parietal cells of the stomach, causing a loss of production of intrinsic factor necessary for vitamin B12 absorption.
Deficiency of folic acid (folate)
Spina bifida Anencephaly Megaloblastic anemia Diarrhea Glositis
Calciferol
Vitamin D
Most toxic fat soluble vitamin
Tocopherol
Vitamin E
Least toxic fat soluble vitamin
Wilsons disease (aka hepatolenticular degeneration)
Results from large accumulation of copper. Patients may have a Kayser-Fleischer ring on the cornea and sunflower cataracts.
Fat soluble vitamin
ADEK
Antioxidants
ACE
What is the initiation codon for every mRNA strand?
AUG, standing for amino acid methionine
Define introns
Part of DNA that does not code for proteins
Define extrons
Part of DNA that does code for proteins and are intermixed with introns.
What are the modifications made to mRNA prior to exportation from the cell nucleus?
Addition of a modified GTP 5’ cap
Addition of a 3’ poly A tail (multiple As)
Introns are spliced from the mRNA sequence.
Define missense mutation
New codon specifies a different amino acid, leading to alterations in protein function (sickle cell disease)
Define nonsense mutation
New codon is a stop codon.
Define Frameshift mutations
Occurs when the addition or deletion of neucleotides causes a shift in the reading frame of codons during translation of RNA, resulting in the production of an incorrect amino acid sequence. These mutations are often nonsense mutations.
Define trinucleotide mutations
Caused by errors in DNA replication that result in an abnormal number of repeated trinucleotides within a gene. Examples of diseases include Huntington’s disease, fragile X syndrome, and myotonic dystrophy.
There is an increase in severity of each successive generation due to increase of the trinucleotide repeat.
Define southern, northern, and western blot techniques.
SunDay, No Rain, Why not Picnic
These different techniques are used to detect either DNA, RNA, or proteins within tissues.
Define vitravene
Vitravene is the first FDA approved anti-sense drug for the treatment of CMV retinitis in immunocompromised patients.
Which drugs interfere with cell walls?
Bacitracin, penicillins, cephalosporins, and vancomycin.
Define bacterial transformation
Transformation is when a segment of DNA is taken up by the cell and incorporated into the bacterial chromosome.
Define bacterial transduction.
A segment of DNA within a phage particle is taken up by the cell and incorporated into the bacterial chromosome.
Define bacterial conjugation
A segment of DNA is directly transferred from a donor male cell to a recipient female cell via a sex pilus.
The male cells contain a F plasmid for the sex pilus.
Define staphylococcus aureus
Gram positive
Catalase positive
Coagulase positive
Causes approximately half of all ocular infections. Including conjunctivitis, blepharitis, bacterial keratitis, hordeola, abscesses, boils, and acute bacterial endocarditis. Staph hypersensitivity resulting from chronic staphylococcus blepharitis can include the formation of infiltrates near the corneal limbus.
Toxic shock syndrome. Includes high fever, vomiting, and watery diarrhea.
Define staphylococcus epidermidis
Gram positive cocci
Catalase positive
Coagulase negative
Define streptococcus pneumonia
Gram positive cocci, facultative anaerobes
Classically grow in pairs
Catalase negative
Can cause pediatric bacterial conjunctivitis and corneal ulcers.
Most common cause of bacterial pneumonia, meningitis, and otitis media.
Which medications would you use to treat blepharitis or a hordeola?
These are classically caused by gram positive bacteria and so can be treated with:
- topical ointments (bacitracin, erythromycin, and polysporin)
- oral agents (dicloxacillin and doxycycline)
You discover a cocci bacteria that is gram positive, catalase negative, and grows in chains. Which streptococcus is this most likely?
Streptococcus pyogenes
Common cause of bacterial pharyngitis (strep throat). Can also cause scarlet fever, rheumatic fever, impetigo, and toxic shock.
List some gram positive rods.
- bacillus anthracis (anthrax)
- clostridium (c. botulinum causes botulism)
- corynebacterium diphtheria (can penetrate intact corneal epithelium)
Define pseudomonas aeruginosa
Motile, oxidase positive, gram negative
- grape juice odor and blue/green pigment.
- common with corneal ulcers in contact lens wearers (must differentiate from amoeba), burn victims, and immunocompromised patients.
Patient presents with painful red eye with thick mucopurulent discharge, often accompanied by hypopyon. What do you want to treat this with?
Should be concerned with pseudomonas. Need gram negative fighting rx (fluoroquinolones).
Which bacteria should you culture with chocolate agar (Thayer Martin Agar)?
Haemophilus influenza (gram negative rod) Neisseria gonorrhea (gram negative cocci, can penetrate intact cornea)
List gram negative cocci bacteria
- neisseria gonorrhea
- neisseria meningitidis (meningitis, culture on blood agar)
- moraxella catarrhalis (shared eye makeup)
- bordatella pertussis (whooping cough)
List gram negative enteric bacteria
- escherichia coli (e. coli, conjunctivitis, corneal ulcers, endophthalmitis)
- klebsiella pneumonia (pneumonia, sinusitis, pharyngitis)
- proteus mirabilus
- serritia marcescens (red pigment)
Two types of mycobacteria (slight gram stain positive, acid-fast)
Mycobacterium tuberculosis (fever, night sweats, weight loss) Mycobacterium leprae (leprosy)
Define treponema pallidum
Sexually transmitted disease either congenital or acquired.
Causes syphilis. Conjunctivitis is seen in either secondary or tertiary phase, not primary.
Argyll-Robertson pupil and interstitial keratitis are two ocular findings.
Treatment with penicillin.
Define different types of chlamydia trachomatis
- chlamydial inclusion conjunctivitis is chronic STD caused by serotypes D to K.
- trachoma conjunctivitis is caused by serotypes A to C. Leading cause of preventable blindness in the world (corneal ulceration).
Patient presents with a chronic red eye and large inferior palpebral conjunctiva follicles.
Chlamydia most likely cause. STD test referral to PCP.
Leading cause of ophthalmia neonatorum
Leading cause in US is chlamydia.
Treatment is erythromycin ointment.
Define rickettsia (gram stain, triad, associated disease, treatment)
Gram negative stain, obligate intracellular parasites transmitted by insect vectors.
- triad of headache, fever, and rash
- causes Rocky Mountain Spotted Fever through tick bites.
- treatment of doxycycline
The bacteria Mycoplasma does not contain a cell wall. Therefore, its resistant to pencillin. What can you treat mycoplasma with instead?
Clindamycin, erythromycin, and azithromycin.
Which cells are responsible for tissue transplant rejections?
T killer cells through type 4 hypersensitivity reactions
Test to be ordered for patient with suspected giant cell arthritis
CBC, ESR, CRP
ESR & CRP indicate 97% specificity.
HLA-B27 tests for
Reactive arthritis
Ankylosis spondylitis
HLA-B54 tests for
Glaucomatocyclic crisis
List all granulomatous inflammation (marked with collections of large, activated macrophages with a squamous cell-like appearance)
- bacterial (tuberculosis, leprosy)
- fungal (histoplasmosis, blastomycosis)
- foreign body (suture, vascular graft)
- unknown (sarcoid, syphilus)
What does histamine cause?
Vasodilation Decreased BP Bronchoconstriction (inhibited by epinephrine) Tachycardia Increase in leukotrienes
Which immunoglobulins are involved with type two hypersensitivity?
IgM and IgG
What causes phlyctenulosis?
Result of type 4 delayed hypersensitivity reaction, usually from staphylococcal infection secondary to blepharitis
Your pediatric patient has a negative RF and a positive
ANA lab results. She has asymptomatic, chronic, bilateral, non granulomatous, anterior uveitis. What should be part of your ddx?
Juvenile idiopathic arthritis (juvenile rheumatoid arthritis)
Sjogrens syndrome triad
Dry mouth, dry eyes, and arthritis.
Affecting females 40-60.