Eye Infections

Question 1

Define Blepharitis

Answer 1

A non-contagious infection to the lower portion of the eyelids and eyelashes

Question 2

Define Dacryocystitis

Answer 2

Inflammation of the lacramal sac. It often causes partial to complete obstruction of the sac

Question 3

Define Opthalmia Neonatorum

Answer 3

eye infection that can be inherited at birth from a mother infected with N. Gonorrhea, Chlamydia, or HSV

Question 4

Define Endophthlamitis

Answer 4

Infection of the aqueous humor in the eye. It is mainly seen following cataract surgery.

Question 5

Define Uveitis

Answer 5

When the blood supply to the eye gets inflamed and starts to close off. There are 3 types, Iritis, Intermediate Uveitis, and Posterior Uveitis

Question 6

Define Periorbital Cellulites

Answer 6

When the skin around the eye is inflamed and can lead to protrusion of the eyeball, meningitis, and blacked sinuses

Question 7

Explain Haemophilus Influenza

Answer 7

Gram (-) Rod that is nonmotile and nonspore forming. Requires both the X and V factors to grow on chocolate agar. Is able to attatch to respiratory epithelial using pili. Forms an endotoxin to ciliated respiratory cells. Nontypable cause otitis media, conjuctivitis, broncitis and pneumoniae. 80% of the population are colonized with this disease

Question 8

Explain Streptococci Pneumoniae

Answer 8

Gram (+) Cocci that is non motile and nonspore forming. It is a fastidious which mean that it grows in 5% carbon dioxide, Generation time is 20-30 minutes under optimal conditions, Alpha-hemolysis, has a capsule which blocks the C3b opsonization in the compliment cascade. There is a antioneumococcal vaccine develloped

Question 9

Define the Quelling Reaction for Strep Pneumoniae

Answer 9

It is used to identify the capsule type for treatment. It allows the antibody to bind to the capsule causing it to swell.

Question 10

Explain Staphylococcus Aureus

Answer 10

Gram (+) cocci with a cytolytic toxin. Coagulase + which allows it to hide in the blood clot. produces Hyaluronidase to allow it to spread easily and Lipases for colonization. Contains protein A which binds to the Fc portion of the antibody to avoid phagocytosis

Question 11

Explain Chlamydia Trachomatis

Answer 11

A obligate intracellular parasite which is the most common STD. If it spreads to the eye it can result in scarring of the conjunctiva. Found in 2 forms the elementary body (Non-replicating but infectious) and the Reticulate body (Replicating but noninfectious). The reticulate body can replicate in 2-3 hours and has a similar cell wall to gram (-).

Question 12

Explain Bartonella Henselae.

Answer 12

A Gram (-) Rod that causes white retinal lesions which is referred to as cat scratch disease.

Question 13

Explain Eikenella Corrodens

Answer 13

Gram (-) Rods which require CO2 and Hemin to grow. The lab is to be notified of the wound is to the neck or head or if it is a result from a human bite. Often associated with chronic infections. It is able to form pits on the agar. Not normally an eye infections

Question 14

Explain Francisella Tularensis

Answer 14

Gram (-) Coccobacillus bacteria which causes Tularemia which is highly infectious. Often from a deer fly or tick, undercooked meat, or handling of a rabbit carcass. symptoms usually are swollen painful lymph nodes, Skin ulcers, and inflammed eyes.

Question 15

Explain Moraxella Catorrhalis

Answer 15

Gram (-) Diplococci. The only other diplococci besides N. Gonorrhea that we have learned.It is oxidase (+) and Abx Resistant. You perform a hockey puck test to identify it.

Question 16

Explain HSV

Answer 16

Causes Viral Blepharitis and has branches in a dendritic pattern that can be seen in the eye.

Question 17

Explain VZV

Answer 17

Causes wart like lesions to the eyelids

Question 18

Explain Adenovirus

Answer 18

Due to direct contact from an infected individual, or fecal oral, or sometimes it is waterborne.

Question 19

Explain Cytomegalovirus

Answer 19

25% of AIDS patients are infected with this. It is transmitted by close personal contact. Most often referred to as having floaters and blind spots. Due to an infiltration of the vascular endothelium. Mainly immune compromised and neonates whos mothers were infected who get it.

Question 20

Explain Fusarium

Answer 20

Rapid growing hyaline fungus which have macroconidia and microconidia growing on their hyphae.

Question 21

Explain Acremonium

Answer 21

Filamentous fungi with 3 species. Mainly an opportunistic infection of immune compromised. Seen with fine narrow hyphae and mature in 5-7 days on potato dextrose agar. Tend to form a velvety texture.

Question 22

Explain Penicillium

Answer 22

A Filamentous fungi that infects immune compromised. Normally spotted with septate hyaline hyphae.

Question 23

Explain Rhizopus Species

Answer 23

Main cause of zygomycosis infections associated iwth rhinocerebral infections. Mainly linked with DKA and immune compromised patients. can be nosocomial due to contaminated tape and tongue depressors. It is often fatal and creates a mycotoxin that can be inhaled. Referred to as black bread mold with aseptate hyphae, sporangiophores and create fast growing dense cottony colonies.

Question 24

Explain Candida species

Answer 24

Cause Endophthalmitis with white chorioretinal spates and roths spots (White hemorrhagic spots) in the eye.

Question 25

Explain pseudomonas species with contact lenses

Answer 25

Gram (-) Rods which are opportunistic and have a grape-like odor to them.

Question 26

Explain Bacillus Cereus

Answer 26

This is one of the most virulent eye microorganism. Has only recently been discovered.

Question 27

Explain Acanthamoeba

Answer 27

Causes Granulomatous amebic encephalitis in AIDS patients. Also forms Keratitis when people use homemade saline solutions. Can be found in swimming pools when people swim with contacts in.

Question 28

Explain Staph Epidermidis

Answer 28

Gram (+) Cocci which are faculatative anaerobe, catalase (+) and form a biofilm.

Question 29

Explain Toxoplasma Gondii

Answer 29

Obtained from contaminated water with cysts in it or oocytes shed by a cat in its liter box. It is an obligate inreacellular parasite and can be identified using indirect immunofluorescent assay.

Question 30

Explain Loa Loa

Answer 30

This is an eye worm which can be contracted from a chrysops fly in the rainforests and swamps of western africa.

Question 31

Explain Onchocerca Volvulus

Answer 31

96% of cases are seen in Africa from the bite of a black fly. The disease migrates from the bite to the peripheral blood and eye.

Question 32

Explain Myiasis

Answer 32

Contracted from the larvae of a fly which embeds in the eye. Mainly seen in Ostrus oris (Sheep bot fly)