Flashcards in Cornea (M2) Deck (64)
What are the layers of the cornea?
2. Bowman's layer
4. Descemet's membrane
What percentage of the corneal thickness is stroma?
What percentage of the refractive power of the eye is due to the cornea?
What is the average thickness of the cornea?
How long does it take to heal the Bowman's membrane?
What layer of the cornea holds mucin and keeps the cornea hydrated?
glycocalyx layer (Slime layer)
What hold the basal corneal cells together?
What holds the basal corneal cells to the basement membrane?
How many cells/mm does a normal adult endothelium have? 1. At what number of cells does edema occur? 2
2. 500 cells/mm
What are the gram positive bacteria that make up the normal flora of the cornea?
1. Staph. aureus (common)
2. Staph. epidermidis (common)
4. Propionibacterium acnes
5. Strep. pneumonia
6. Strep. viridans
What are the gram negative bacteria that make up the normal flora of the cornea?
1. E. coli
5. Pseudomonas (rare)
6. Haempjilus influenzae (rare)
What are the fungi that make up the normal flora of the cornea?
candida (less common)
What is the enzyme on the cornea that breaks down bacterial cell walls?
What is the metal chelating protein found on the cornea?
What is the antibody the prevents bacterial adherence on the cornea?
What are the risk factors for microbial keratitis?
1. CL wearer
3. topical corticosteroids
4. chronic corneal surface disease
5. ocular surgery
6. ocular adnexal conditions
7. systemic disease
What are the bacteria capable of corneal penetration without epithelial compromise?
1. Neisseria gonorrhea
2. Neisseria meningitidis
3. Hemophilus influenzae
4. Corynebacteria diphtheria
What is required for the infection to be an infectious corneal ulcer?
1. eroded epithelium
2. underlying stromal infiltrate
What are the proper times to culture a kerititis?
1. non-responsive lesion
2. extensive infiltration of cornea
3. lesion >1.0mm that is central or paracentral
4. post-surgical infection
5. monocular patient
6. immunocompromised patient
What does the prescription abbreviation "ad lib." mean?
freely, as needed
What does the prescription abbreviation "a.c." mean?
What does the prescription abbreviation "b.i.d." mean?
twice a day capsule
What does the prescription abbreviation "gtt." mean?
What does the prescription abbreviation "h.s." mean?
What does the prescription abbreviation "p.c." mean?
What does the prescription abbreviation "p.o." mean?
What does the prescription abbreviation "p.r.n." mean?
What does the prescription abbreviation "oint" mean?
What does the prescription abbreviation "qAM" mean?