Prunuske -- Conjunctivitis

Question 1

Blepharitis

Answer 1

eye lid infections

Question 2

Conjunctivitis

Answer 2

conjunctiva- thin membrane infection

Question 3

Kerititis

Answer 3

cornea infection

vision defects, photophobia, pain (cornea has lots of nerve endings), and foreign body sensation

Viral keratitis is caused by HSV-1, adenovirus, and VZV.
Bacterial keratitis Staph. aureus and epidermidis, Pseudomonas aerugrinosa, and Bacillus cereus.

Treatment- for bacteria Moxifloxacin eye drops
_ for HSV-1_ **trifluridine + acyclovir **

Question 4

Keratoconjunctivitis

Answer 4

conjunctiva and cornea infection

Question 5

Uveitis

Answer 5

iris, ciliary body, and choroid infection

Question 6

Chorioretinitis

Answer 6

choroid and retinal layers infection

Blood borne route via retinal arteries, frequently manifestation of systemic disease

Congenital Toxoplasma (parasite) and CMV (ganciclovir implant) are most common especially in HIV and neonates

Question 7

Endophthalmitis

Answer 7

aqueous and vitreous humor

Question 8

tears contain what?

Answer 8

Secretory IgA is a dimer
Secretory piece protects IgA from being degraded

Question 9

most common cause of conjunctivitis

Answer 9

adenovirus

(also alergies, chemical exposure)

Question 10

bacterial vs. viral vs. allergic conjunctivitis

Answer 10

bilateral (bacterial: 50-75%; viral; 35%, A = mostly)

discharge (bacterial: macopurulent; viral: watery)

MUST ADD MORE

Question 11

Allergic rhinoconjunctivitis (hay fever)

Answer 11

antigen –> b-cell –> IgE –> IgE binds mast cell –> subsequent exposure –> histamine release from mast cell.

Management
Antihistamines, mast cell stabilizers, nonsteroidal anti-inflammatory drugs
Avoid antigen and glucocorticoid
Steroids effective but can cause complications like glaucoma, cataract, and 2ndary infections

Question 12

Viral conjunctivitis

Neonatal = ?

Post-natal = ?

Answer 12

HSV-1

Adenovirus

Question 13

Adenovirus

Answer 13

non-enveloped, double-stranded DNA virus

Lytic in epithelial cells and latent in lymphoid

highly contagious spread through fomites like swimming pools

Adenovirus infects epithelial cells of respiratory tract (4,7), conjunctiva (invasive 19,37), and
 enteric organs (40,41,42).  What determines this specificity? ... coxsackie adenovirus receptors

Question 14

Acute bacterial conjunctivitis (mucopurulent)

Answer 14

Children- Staphylococcus aureus, Streptococcus pneumoniae, Haemophilus influenzae, Moraxella

Adults- Staphylococcus aureus, Strep. Pneumonia, Escherichia coli, Pseudomonas aeruginosa, Moraxella

Empiric treatment with both Gram positive and negative coverage: Moxifloxacin solution (fluroquinolone) (best coverage, expensive, >3 yr)

Question 15

What is the mechanism of action for moxifloxacin, trimethoprim, and polymyxin B?

Answer 15

moxifloxacin: binds DNA gyrase (TOPO II)

trimethoprim: binds to DHFR

polymyxin B: binds phosphitidal ethanolamine and creates holes in outer membrane

Question 16

Hyperacute bacterial conjunctivitis

Answer 16

**Neisseria gonorrhoeae **

Copious yellow-green discharge (purulent)
Preauricular adenopathy

Gram stain for gram-negative intracellular diplococci and growth on chocolate agar supplemented with vancomycin, colistin, nystatin, and trimethoprim (nonsterile site)

Treat promptly with systemic ceftriaxone

Question 17

Ophthalmia neonatorum

Answer 17

conjunctivitis or keratoconjunctivitis occurring within first four weeks of birth

(N. gonorrhoeae, C. trachomatis, Staphylococcus, Streptococcus, E. coli, H. influenzae or H. simplex)

Prophylaxis with **erythromycin ointment **

Question 18

erythromycin, azithromycin

Answer 18

macrolides

Inhibits translation by binding 23S rRNA of the 50S subunit

Spectrum: Broad coverage of respiratory pathogens, Chlamydia

Resistance: Increased efflux, hydrolysis of drug by esterases, methylation of drug binding site

Adverse effects:
GI discomfort, Hepatic failure, and Prolonged QT interval

Question 19

Inclusion conjunctivitis (serotypes D-K)

Trachoma (serotypes A-C)

Answer 19

_Chlamydia trachomatis _

Trachoma = leading cause of blindness worldwide

Treate with azithromycin

Question 20

Chlamydia trachomatis

life cycle

Answer 20

Elementary body (EB) enters epithelial cells, converts to reticulate body (RB), and then replicates using binary fission

elementary body has ridgid outer body

Question 21

Chronic conjunctivitis is associated with….

Answer 21

Blepharitis: Inflammatory disease of the eyelid margin where too much oil is produced

Stye- external localized inflammation often on lower lid due to bacterial growth in eyelash follicle, if forms inside or under eyelid called hordeolum
Chalazion- (lipogranulomas)”small lump” plugging of the meibomian gland

Treatment: Keep lid clean. Warm compress or massage to open gland. Erythromycin ointment.

Question 22

keratoconjunctivitis with HSV-1

Answer 22

Similar presentation to adenovirus although lesions can be painful especially if scarring of the cornea occurs and often only one eye

Avoid corticosteroids since can facilitate corneal penetration

If corneal involvement treat with topical trifluridine and systemic acyclovir and consider prophylactic treatment with erythromycin to prevent bacterial superinfection

Question 23

acyclovir and ganciclovir are prodrugs

Answer 23

Inhibits viral DNA synthesis by acting as a competitive substrate for viral DNA polymerase and lead to chain termination

requires thymidine kinase (?)

Question 24

Trifluridine

Answer 24

pyrimidine analog effective against acyclovir resistant virus because it can be phosphorylated by host kinases also making it much more toxic and should only be used topically

Question 25

Pseudomonas aeroginsoa

Answer 25

Gram negative, aerobic rod, flagella

Question 26

Answer 26

CMV retinitis begins at periphery and can spread like “brushfire”

A type of Chorioretinitis- blurred vision and visual field defects

Question 27

Viral conjunctivitis epidemics are often caused by …

Answer 27

adenovirus

Question 28

Treat neonates prophylactically with …

Answer 28

erythromycin to decrease opthalmia neonatorum

Question 29

Blepharitis is often associated with …

Answer 29

conjunctivitis

Question 30

Chorioretinitis is usually linked to …

Answer 30

systemic disease (CMV and HIV)

Question 31

Interior eye infections like endopthalmitis may be transmitted through ….

Answer 31

blood or introduced during surgery.