Flashcards in Retina and Vitreous Vol. 1 Deck (32)
What percentage of the volume of the globe does the vitreous occupy?
Name the 3 components of the vitreous.
1. Water 2.Collagen 3.Hyaluronic acid
What is the name of the retrolental indention of the anterior hyaloid membrane of the vitreous?
Where is the vitreous base located?
Straddles the ora serrata, from 2 mm anterior to 3 mm posterior
Name the 4 locations of firm vitreous attachment.
1. Vitreous base 2.Retina vessels 3. Optic disc 4. Macula
When does liquefaction of the vitreous start?
As early as age 2
What pocket does liquefaction of the vitreous form early in life?
Premacular bursa, or precortical pocket
During vitrectomy, what medication can be introduced to highlight vitreous liquefaction cavities?
What causes the yellow color of the macula?
Carotenoids (e.g. lutein and zeaxanthin)
What are the two functions of the carotenoids?
1. Antioxidants 2. Filter blue light
Where is the fovea located in relation to the optic disc?
4 mm temporally and 0.8 mm inferior
Where are the dentate processes located?
Where are dentate processes most prominent?
Nasal peripheral retina
What can an enclosed ora bay be confused for?
Peripheral retinal hole
What are the dentate processes?
Small portions of retina projecting into the ora serrata
What are ora bays?
Extensions of the pars plana extending onto the retinal side
How many degrees of the visual field does the fovea constitute?
Approx. 5 degrees
What causes an enclosed ora bay?
Connections between dentate processes and ora bays
What are the only types of cells found within the central fovea?
Cones and Muller cells
What is the anatomic boundary of the foveola?
Area within the fovea that lacks the ganglion cell layer and inner nuclear layer
Where are cones most heavily concentrated?
Where is concentration of rods the greatest?
Approx. 20 degrees from fixation
What is the density of rods approx. 20 degrees from fixation?
What are the two components of rhodopsin?
Vitamin A and opsin
What photoreceptor contains rhodopsin?
Where is opsin located within the cones?
Photoreceptor outer segments
How many types of opsin are found within cones?
Three (red, green, and blue)
What phagocytizes the discs of rods once they are shed from the outer retina?
What gene encodes for ABCR protein?