POSTERIOR SEGMENT - Vitreous

Question 1

What is the space called in the centre of the hyaloideocapsular ligament (Weiger)?

Answer 1

Berger’s space

Question 2

Where does Cloquet’s canal travel from?

Answer 2

Courses from Berger’s space posteriorly through the central vitreous until the space of Martegiani at the optic nerve

Question 3

What is the vitreous?

Answer 3

Inert transparent jelly like hydrophilic gel that serves optical function of the eye, forms 2/3rd of volume of the eye

Question 4

What are the components of the vitreous?

Answer 4

1. 98% water
2. 2% structural proteins (type 2 collagen)
3. Extracellular matrix components
   - hyaluronic acid
   - chondroitin sulphate (versican)
   - opticin
   - VIT-1
   - fibrillins

Question 5

What are the main collagen fibres in the vitreous?

Answer 5

*VITREOUS JELLY IS 2 VERY NICE *
1. Type 2 - major component
2. Type 5 (V) collagen
3. Type 9 collagen

Question 6

What is composed in the vitreoretinal interface?

Answer 6

Fibronectin/laminin adhesions at the vitreoretinal inferface with type 4 collagen

Question 7

What is stickle syndrome? What are the differences between type 1 and type 2? -

Answer 7

AD disorder of type 2 collagen - at greater risk of giant retinal tears

Type 1: Mutations in COL2A1 gene - membranous vitreous
Type 2: Mutations in COL11A1 gene - beaded vitreous

Question 8

What is the posterior hyaloid face?

Answer 8

From vitreous base to optic disc

Question 9

What is the cortical vitreous?

Answer 9

Entire peripheral zone of the vitreous (100 microns) which is more condensed and fibrillar part of the vitreous

Question 10

What are the cells seen in the vitreous?

Answer 10

Predominantely acellular

Contain hyalocytes (similar to macrophages)

Question 11

Where are the strong attachments of the vitreous? (4)

Answer 11

1. Peripheral retina / ora serrata and pars plana via vitreous base
2. Posterior lens capsule (Weigner’s ligament)
3. Margin of optic disc (base of hyaloid canal)
4. ILM of retina (especially near retinal vessels - weakest)

Question 12

What are the age related changes in the vitreous? (4)

Answer 12

1. Aggregation of collagen fibrils
2. Pooling of hyalronic acid
3. Liquefaction centrally then peripherally
4. Increased vitreous volume

Question 13

What is the difference between the canal of petit and canal of hannover?

Answer 13

the canal of Petit is a potential space near the lens

the canal of Hannover is a small, normal variant space near the retina in the posterior vitreou