Antibiotic Agents (M2) Flashcards
What are the options for MGD to help express the glands?
- eye masks
- Mastrota paddle
- debridement of line of Marx
- Lipiflow
- Intense pulsed light (IPL)
What are the four things that can cause Idiopathic Intracranial Hypertension?
- tetracyclines
- high dose Vit A
- nalidixic acid
- birth control and pregnancy
How long is a patient usually considered contagious when they have bacterial conjunctivitis?
Not contagious once they have been treated for over 24 hours
What is the common bacteria of the eye that is usually involved in adult inclusion conjunctivitis? 1. Gram pos or neg? 2
- Chlamydia trachomatis
2. gram neg
What is the coverage required for a hordeolum?
coverage against Staph aureus
What are the lid hygiene products that are soap only?
OcuSoft original lid scrubs/foam cleanser
What are the conditions in which antibiotic resistance is more likely?
- systemic antibiotics
- bacteriostatic
- not used to completion
- overuse of antibiotic
What are the ophthalmic uses for tetracyclines?
- meibomian gland dysfunction (MGD)
- ocular rosacea
- chalazia
- RCE
- uveitis from Lyme disease
What are the likely offending organisms of preseptal cellulitis?
- Staph aureus
- Staph epidermidis
- Strep
- H. flu
What are the indications of oral antibiotics in primary eyecare?
- glandular and deep tissue lid disease
2. ocular manifestations of systemic disease
What are the two main B-lactam classes of meds relevant to eyecare? 1. What are the DOC for? 2
- penicillins and cephalosporins
2. infectious lid disease
When is doxycycline dosed below MIC?
- Meibomianitis
- Meibomian Gland Dysfunction (MGD)
- Ocular Rosacea
What is the pervasive bacteria of the normal ocular flora that is characteristic in pediatric populations? 1. Gram pos or neg? 2
- Haemophilus influenzae (H. flu)
2. gram neg
What process of the folic acid synthesis does trimethoprim inhibit?
dihydrofolate reductase (dihydrofolic acid to tetrahydrofolic acid)
What does bacterial lipase break meibomian lipids into?
- inflammatory, free fatty acids (froth)
2. solid lipid components (meibum)
What is the BlephEx used for?
- anterior bleph
- MGD and lid debridement
- demodex
What are the management issues involved in someone with a paper cut on the their cornea?
- prophylactic Ab
- photophobia (test for CB spasm w/ anesthetic)
- recurrent corneal erosion
What are the cell wall inhibiting antibiotics that contain a B-lactam ring?
- penicillins
- cephalosporins
- carbapenems
- aztreonam
What are the indications of topical antibiotics in primary eyecare?
- bacterial conjunctivitis
- microbial keratitis (MK)
- surface lid disease (anterior bleph and MGD)
- prophylaxis
What were the findings of the Steroids for Corneal Ulcers Trial (SCUT study) for the only conditions in which to add a steroid to antibacterial treatment?
- case cultured positive for bacteria
- patient treated on stand alone antibiotic for 48 hours
- ulcer showing improvement with re-epithelialization)
- in center of vision
What are dysfunctioning in ocular rosacea? 1. What are the signs? 2
- sebaceous glands
2. MGD, greasy skin, nose telangectasia
What is the etiology of preseptal cellulitis?
- trauma
- insect bite
- spread of localized lid infection
- extension of ethmoid sinus infections
What is an acute inflammation of the lacrimal sac called that is red, warm, and tender to the touch?
dacryocystitis
What are the signs and symptoms of orbital cellulitis?
- pain and tenderness
- redness
- decreased vision from retrobulbar inflammation
- restricted eye movements
- often have a fever
What are the mechanisms of action to help eliminate bacteria?
- cell wall inhibitors
- cell membrane inhibitors
- protein synthesis inhibitors
- intermediate metabolism/ folic acid synthesis inhibitors
- DNA replication inhibitors
What is the common bacteria of the eye that is the great masquerader? 1. Gram pos or neg? 2
- Treponema pallidum
2. gram neg
What is the follow up like for a patient with a cornea paper cut?
see every day until re-epithelialized
Which type of demodex is found in sebaceous glands?
Demodex brevis
How long does a Z-pak and Tri-pak maintain MIC for MGD or infectious lid disease dosing?
up to 10 days
What are the advanced treatments of recurrent corneal erosions?
- anterior stromal puncture
- photo Therapeutic keratectomy
- amniotic membrane
What process of the folic acid synthesis does pyrimethamine inhibit?
dihydrofolate reductase (dihydrofolic acid to tetrahydrofolic acid)
What is the lid hygiene product that has the active ingredient Linalool?
SteriLid by TheraTears
What is the lid hygiene product that has 0.01% hypochlorous acid and uses no additive or preservatives? 1. What do they have a high kill rate of? 2
- Avenova
2. Staph aureus, Staph epi, MRSA, Demodex
What is the acute infection of the lid tissue anterior to the posterior septum that goes canthus to canthus?
preseptal cellulitis
What are the most pervasive bacteria in the ocular flora, from most to least (Gram pos or neg)?
- Staph aureus (gram pos)
- Staph epidermidis (gram pos)
- Strep pneumoniae (gram pos)
What are the signs of MGD?
- widening of lid margin
- notching in lid margin
- telangectasia
- toothpaste-like meibum
What are the most common mechanisms of resistance to antibiotics?
- produce enzyme that deactivates
- alters surface cell receptor
- block entry of antibiotic into cellular contents
What was the large improvement made from 3rd generation to 4th generation fluoroquinolones?
4th gen inhibit DNA gyrase and topoisomerase IV in both gram (+) and (-)
What is the usual location of infectious corneal lesions? 1. Number of lesions? 2. Lesion size? 3. Degree of stain? 4. Pain level? 5. Pattern of infection? 6. Anterior chamber reaction? 7
- central 6mm
- single
- greater than 1mm
- staining = lesion
- severe pain
- diffuse injection
- cells in AC
What is the procedure for the in office treatment of demodex?
- instill anesthetic
- dab and rub 50/50 Tea tree oil and macadamia nut oil on lashes
- close eyes for 10 min
- repeat
- rinse thoroughly
As a class, does Staph show more resistance to Penicillins or Cephalosporins?
Penicillins
What are the three drug classes of protein synthesis inhibiting antibiotics?
- aminoglycosides
- tetracyclines
- macrolides
What are the two individual drugs that are protein synthesis inhibiting antibiotics but are not in the umbrella of the classes?
- chloramphenicol
2. clindamycin
What is the coverage required for a preseptal cellulitis?
- Staph aureus
- Staph epidermidis
- Haemophilus influenza
What two factors are essential to the development of a contact lens peripheral ulcer?
- hypoxia
2. bacterial overgrowth
What are the lid hygiene products that are soap plus disinfectant?
Ocusoft Plus lid scrubs/foam cleanser
What is the only condition that shows follicles on the superior palpebral conjunctiva?
adult inclusion conjunctivitis
What does the TRUST study show?
MRSA is most susceptible to trimethoprim
What agents changed the way microbial keratitis was treated? 1. Why? 2
- fluoroquinolones
2. had H.flu and pseudomonas coverage without needing a combo agent
What form of doxycycline has greater GI upset and lower absorption? 1. Which has less GI and more absorption? 2
- hyclate
2. monohydrate
What are the non-infectious lid diseases?
- MGD
- rosacea
- chalazia
Which antibacterial drug class has the least selective toxicity?
cell membrane inhibitors
What are the three major causes of infection?
- break in defense mechanism (skin)
- immunocompromised
- virulent strains
Why are fluoroquinolones good agents for infectious lid disease?
- cover Staph and H.flu
- Dosing good
- penetrate glands well
What is the lid hygiene product that has 0.02% hypochlorous acid?
OcuSoft HypoChlor
What study proved that Besivance is the most effective fluoroquinolone for microbial keratitis?
ARMOR study
Which type of demodex is found in hair/lash follicles?
Demodex folliculorum
What was the result of the study comparing oral azithromycin and oral doxycycline for the treatment of MGD?
- equal improvement in ocular symptoms
- Zpak = less rednedd and ocular surface staining
- Zpak less GI distress
What are the cell wall inhibiting antibiotics that do not contain a B-lactam ring?
- Bacitracin
2. vancomycin
What is the common bacteria of the eye that is water loving and therefore is associated with CL’s? 1. Gram pos or neg? 2
- Pseudomonas aeruginosa
2. gram neg
What process of the folic acid synthesis do sulfonamides inhibit?
dihydropterate synthetase (PABA to folic acid)
What are the two different rules for pediatric dosing of Augmentin?
- 25mg/kg/day in 2 divided doses (2.2 lbs=1 lb)
2. Clarks rule: Adult dose x weight (lbs)/150
What is the usual location of sterile corneal lesions? 1. Number of lesions? 2. Lesion size? 3. Degree of stain? 4. Pain level? 5. Pattern of infection? 6. Anterior chamber reaction? 7
- peripheral
- multiple
- less than 1mm
- staining less than lesion
- mild to mod pain
- localized injection
- no/rare cells in AC
What is the coverage required for a lid disease in kids?
H.Flu as well as Staph
What is the common bacteria of the eye that can penetrate intact corneal epithelium? 1. Gram pos or neg? 2
- Neisseria gonorrhoeae
2. gram neg
Are gram (+) or (-) more difficult to treat against? 1. Why? 2
- gram (-)
2. have an outer membrane
With an increase in generations of cephalosprins what tends to happen to: 1. Gram (-) coverage; 2. Gram (+) coverage; 3. resistance?
- increase
- decrease
- decrease
What is released in the cornea after trauma that is inhibited by tetracycline and inhibits collagen proteins used in the healing process?
MMP’s
What are the different types of amniotic membranes available for RCE?
- PROKERA
- AmbioDisk
- BioD Optix
When is doxycycline dosed at MIC?
- Lyme disease
2. Rocky Mountain Spotted Fever
