Shared Flashcard Set

Details

Ocular Physio Test 1
Lecture 1: Orbit
13
Science
Professional
09/27/2007

Additional Science Flashcards

 


 

Cards

Term
Which part of the orbit was first developed embryologically?
Definition
Maxillary bone
Term
Sphenoid bone was formed by which type of ossification?
Definition
endochondral (preformed in cartilage and then ossified) and membranous (ossified from CT)
Term
Function of the orbit?
Definition
support and provide protection to the orbit and soft tissue
Term
The 7 bones that make up the orbit
Definition
Sphenoid
Frontal
Ethmoid
Maxillary
Zygomatic
Palatine
Lacrimal bones
Term
Which orbital wall is the thickest?
Definition
Lateral wall (zygomatic bone with tubercle where lateral canthal ligament, LR, LR muscle check ligament, and aponeurosis of levator palpebrae superioris muscle attach)
Term
Which area of the orbit is the most susceptible to blunt force trauma?
Definition
orbital floor (supported by the maxillary-ethmoid buttress and the infraorbital sulcus/canal)
Term
What are the symptoms from a blow out fracture?
Definition
loss of vision
diplopia
enophthalmos (change in the position of the eye in the globe)
numbness of the cheeck
Term
Which orbital wall is less susceptible to fracture eventho it's extremely thin, and why?
Definition
Medial/Nasal floor; because of it's honeycombed structure
Term
What is a tripod fracture? What are the symptoms seen?
Definition
A fracture along the suture line of the orbit due to blunt trauma to the cheek.

depressed cheek, muscle spasm, difficulty opening mouth
Term
Exothalmos
Definition
forward displacement of the globe

Most common cause is Grave's Diz where muscle and CT increase in size and fat content which eventually replaced by scar tissue-->pushing eye forward

Possible causes:
-severe myopia
-buphthalmos (infantile glaucoma)
Term
Enophthalmos
Definition
Retro-displacement of the globe posterior into the orbit

Possible causes:
-Trauma
-Surgery
-previous irradiation
-metastatic lesion may lead to pseudoexophthalmos in the contralateral eye
Term
Proptosis
Definition
forward displacement of any object
Term
Normal measurement of exothalmos
Definition
Normal: 15-17mm
Caucasians: 11-21
African-Americans: 12-24

Difference of >2mm bt 2 eyes is significant
Supporting users have an ad free experience!