Week 3 - A. Prunuske (Eye Infections)

Question 0

What is conjunctivitis an infection of?

Answer 0

Thin membrane (conjunctiva, obviously)

Question 1

What is blepharitis an infection of?

Answer 1

Eye lid

Question 2

What is an infection of the cornea called?

Answer 2

Keratitis

Question 3

What is the medical term for an infection of BOTH the conjunctiva and the cornea?

Answer 3

Keratoconjunctivitis

Question 4

What part of the eye is infected in Uveitis?

Answer 4

Middle Layer:

iris, ciliary body, and choroid

Question 5

What part of the eye is infected in Chorioretinitis?

Answer 5

Choroid and retinal layers

Question 6

What part of the eye is infected in Endophthalmitis?

Answer 6

Aqueous and vitreous humor

Question 7

What kind of people are more likely to get trauma related to abrasions, scratches, and microabrasions?

Answer 7

Contact lens wearers

Question 8

Why does dysfunctional tear states or decreased tear production increase the susceptibility of eye infections?

Answer 8

Tears are important defense mechanism.

Less tears –> more opportunity for pathogens to cause trouble.

Question 9

How are deeper eye infections usually acquired?

Answer 9

Invaded from blood borne carriage

Question 10

Chronic conjunctivitis is associated with what other common eye infection?

Answer 10

Blepharitis

Question 11

What is overproduced in Blepharitis?

Answer 11

Too much oil is produced in the eyelid margin

Question 12

What pathogen is most commonly associated with Blepharitis/Chronic conjunctivitis/Stye/Hordeolum?

Answer 12

Staphylococcus epidermidis

Question 13

What is treatment for Blepharitis/Stye?

Answer 13

Keep lid clean, Warm compress, Erythromycin ointment

Question 14

What two layers of the eye act as a physical barrier to prevent invasion?

Answer 14

Sclera & Cornea

Question 15

What do tears contain for defense mechanism and lubrication?

Answer 15

sIgA and Lysozyme

Question 16

What defense cells are present in the conjunctiva?

Answer 16

Lymphocytes, plasma cells, neutrophils, and mast cells

produce antibodies and cytokines

Question 17

How does blinking act as a defense mechanism for the eye?

Answer 17

Inhibits microbial attachment

Question 18

What causes red eye, irritation, and sensitivity in conjunctivitis?

Answer 18

Dilation and congestion of supepithelial vessels

Question 19

What is the most common viral cause of conjunctivitis?

Answer 19

Adenovirus

Question 20

What type of conjunctivitis most commonly causes mucopurulent discharge bilaterally?

Answer 20

Bacterial

Question 21

What symptoms are typical in Allergic Conjunctivitis?

Answer 21

Bilateral eyes, Redness, Pruritic

Question 22

What are some non-infectious causes of conjunctivitis?

Answer 22

Allergic rhinoconjunctivitis (hay fever), chemical reaction, prolonged use of ocular medications, neoplsm, irritation from contact lens, or foreign body.

Question 23

What antibody response is most common in Allergic rhinoconjunctivitis (hay fever)?

Answer 23

IgE response

Question 24

What things do you want to avoid in the management of allergic rhinoconjunctivitis?

Answer 24

Avoid antigen and glucocorticoid

Question 25

Why do you want to avoid Steroids if possible when treating allergic rhinoconjunctivitis (hay fever)?

Answer 25

More likely to develop secondary infections. | Cause complications: glaucoma, cataracts

Question 26

What is the best treatment for allergic rhinoconjunctivitis?

Answer 26

Antihhistamines, mast cell stabilizers, nonsteroidal anti-inflammatory drugs

Question 27

What is the most common neonatal cause of viral conjunctivitis?

Answer 27

HSV

Question 28

What is the most common post-natal cause of viral conjunctivitis?

Answer 28

Adenovirus

Question 29

What are common indicators of viral conjunctivitis?

Answer 29

Watery/clear discharge, unilateral symptoms, recent URI

Question 30

What is the typical treatment for viral conjunctivitis?

Answer 30

Cold compress, topical vasoconstrictor

Question 31

What virus commonly causes conjunctivitis and is ds-DNA, non-enveloped, and highly contagious through fomites in swimming pools?

Answer 31

Adenovirus

Question 32

What determines the specificity of Adenovirus that infects the conjunctiva?

Answer 32

antigen ability to interact with cellular receptors

Question 33

What three pathogens most commonly cause acute bacterial conjunctivitis in children?

Answer 33

Staph aureus, Strep pneumoniae, and Haemophilus influenzae

Question 34

What common pathogen causes acute bacterial conjunctivitis in Adults?

Answer 34

Staph aureus

Question 35

What is the typical treatment for acute bacterial conjunctivitis?

Answer 35

Empiric treatment for BOTH Gm -/+ Polytrim (Trimethoprim and polymixin) Fluorquinolone (moxifloxacin)

Question 36

What is MOA of trimethoprim?

Answer 36

Bacteriostatic - inhibits bacterial dihydrofolate

Question 37

What is MOA of Polymyxin B?

Answer 37

Binds to lipopolysaccharid --> creating holes in membrane --> release cellular contents (Gm -)

Question 38

What is MOA of Moxifloxacin?

Answer 38

Topo II inhibitor

Question 39

What is the pathogen that causes Hyperacute bacterial conjunctivitis?

Answer 39

Neisseria gonorrheoeae (less often Neisseria meningitidis)

Question 40

What special agar is used to identify gram-negative diplococci like Neisseria gonorrhoeae?

Answer 40

Chocolate agar (nom nom)

Question 41

What antibiotic is a cell wall inhibitor and is used promptly to treat hyperacute bacterial conjunctivitis?

Answer 41

Ceftriaxone

Question 42

What condition can occur if conjunctivitis or keratonconjunctivitis is acquired within the first four weeks of birth?

Answer 42

Ophthalmia neonatorum! (thats why all new babies get erythromycin ointment on their eyes)

Question 43

Erythromycin and Azithromycin are Macrolides that inhibit translation by binding to what part of the ribosome?

Answer 43

BIG SUBUNIT (50S)

Question 44

What are common adverse side effects of Macrolides like Erythromycin and Azithromycin?

Answer 44

GI discomfort, hepatic failure, and prolonged QT | check other meds due to cytochrome P450 inhibition

Question 45

What is the leading cause of blindness WORLDWIDE?!?

Answer 45

Trachoma caused by Chlamydia (serotypes A-C)

Question 46

Inclusion conjunctivitis is caused by serotypes D-K of what pathogen?

Answer 46

Chlamydia trachomatis

Question 47

What is preferred treatment for eye infections caused by Chlamydia?

Answer 47

Azithromycin

Question 48

What form of Chlamydia trachomatis enters epithelial cells?

Answer 48

Elementary bodies

Question 49

What form does Chlamydia convert to after it has entered the epithelial cells?

Answer 49

Reticulate body

Question 50

Which form of Chlamydia has a more rigid outer membrane?

Answer 50

Elementary bodies

Question 51

What eye infection does HSV-1 cause?

Answer 51

Keratoconjunctivitis

Question 52

What is the typical presentation of Keratoconjunctivitis caused by HSV-1?

Answer 52

unilateral infection, similar to adenovirus, with PAINFUL corneal lesions

Question 53

What do you want to avoid with corneal lesions/penetrations in treating keratoconjunctivitis?

Answer 53

Corticosteroids are bad for the cornea!

Question 54

What topical drug and systemic antibiotic should you use if there is corneal involvement in keratoconjunctivitis caused by HSV-1?

Answer 54

Trifuridine and Acyclovir

Question 55

Why is Trifluridine a more toxic drug?

Answer 55

It can be phosphorylated by the host kinases to become active (not viral specific kinases like acyclovir)

Question 56

What conditions can increase your risk of getting keratitis?

Answer 56

Trauma, drying of epithelia, and hypoxia

Question 57

What is viral keratitis caused by?

Answer 57

HSV-1 (also adenovirus & VZV)

Question 58

What are common pathogens in bacterial keratitis?

Answer 58

Staph. aureus/epidermis, Pseudomonas aerugrinosa, and Bacillus cereus

Question 59

What is the treatment for bacterial keratitis?

Answer 59

Moxifloxacin eye drops

Question 60

What is cool about Pseudomonas?

Answer 60

Produces a blue/green pigment (pyocyanin) that inhibits mitochondrial enzymes that disrupt ciliary beating in the eye => Virulence factor

Question 61

What cell surface adherence factors produced by Pseudomonas destroy corneal epithelium in bacterial keratitis?

Answer 61

Cytotoxins like elastase and alkaline protease

Question 62

What process actually damages the cornea leading to scarring and loss of visual acuity during a keratitis caused by Pseudomonas aerginosa?

Answer 62

host immune response