Retina and Vitreous Vol. 1

Question 1

What percentage of the volume of the globe does the vitreous occupy?

Answer 1

80%

Question 2

Name the 3 components of the vitreous.

Answer 2

1. Water 2.Collagen 3.Hyaluronic acid

Question 3

What is the name of the retrolental indention of the anterior hyaloid membrane of the vitreous?

Answer 3

Patellar fossa

Question 4

Where is the vitreous base located?

Answer 4

Straddles the ora serrata, from 2 mm anterior to 3 mm posterior

Question 5

Name the 4 locations of firm vitreous attachment.

Answer 5

1. Vitreous base 2.Retina vessels 3. Optic disc 4. Macula

Question 6

When does liquefaction of the vitreous start?

Answer 6

As early as age 2

Question 7

What pocket does liquefaction of the vitreous form early in life?

Answer 7

Premacular bursa, or precortical pocket

Question 8

During vitrectomy, what medication can be introduced to highlight vitreous liquefaction cavities?

Answer 8

Triamcinolone

Question 9

What causes the yellow color of the macula?

Answer 9

Carotenoids (e.g. lutein and zeaxanthin)

Question 10

What are the two functions of the carotenoids?

Answer 10

1. Antioxidants 2. Filter blue light

Question 11

Where is the fovea located in relation to the optic disc?

Answer 11

4 mm temporally and 0.8 mm inferior

Question 12

Where are the dentate processes located?

Answer 12

Peripheral retina

Question 13

Where are dentate processes most prominent?

Answer 13

Nasal peripheral retina

Question 14

What can an enclosed ora bay be confused for?

Answer 14

Peripheral retinal hole

Question 15

What are the dentate processes?

Answer 15

Small portions of retina projecting into the ora serrata

Question 16

What are ora bays?

Answer 16

Extensions of the pars plana extending onto the retinal side

Question 17

How many degrees of the visual field does the fovea constitute?

Answer 17

Approx. 5 degrees

Question 18

What causes an enclosed ora bay?

Answer 18

Connections between dentate processes and ora bays

Question 19

What are the only types of cells found within the central fovea?

Answer 19

Cones and Muller cells

Question 20

What is the anatomic boundary of the foveola?

Answer 20

Area within the fovea that lacks the ganglion cell layer and inner nuclear layer

Question 21

Where are cones most heavily concentrated?

Answer 21

Central fovea

Question 22

Where is concentration of rods the greatest?

Answer 22

Approx. 20 degrees from fixation

Question 23

What is the density of rods approx. 20 degrees from fixation?

Answer 23

160,000 rods/mm2

Question 24

What are the two components of rhodopsin?

Answer 24

Vitamin A and opsin

Question 25

What photoreceptor contains rhodopsin?

Answer 25

Rods

Question 26

Where is opsin located within the cones?

Answer 26

Photoreceptor outer segments

Question 27

How many types of opsin are found within cones?

Answer 27

Three (red, green, and blue)

Question 28

What phagocytizes the discs of rods once they are shed from the outer retina?

Answer 28

RPE

Question 29

What gene encodes for ABCR protein?

Answer 29

ABCA4

Question 30

What material accumulates in the retina and RPE in Stargardt disease?

Answer 30

Retinoid-based fluorophores (e.g. A2E)

Question 31

What protein is defective in Stargardt disease?

Answer 31

ABCR

Question 32

What accumulates in the outer segments of photoreceptors in Stargardt disease?

Answer 32

All-trans-retinol