Vitreous (Attachments, age changes, vitreous hemorrhage, Vitreous Detachment)

Vitreous
Vitreous is an inert, avascular, transparent, jelly like structure.
Serve as one of refractive media of the eye and has optical functions.
It gives structural integrity to eye and provide nutrients to the lens, ciliary body and retina.
Constitute 80% volume of the eye.
Contain collagen fibrils, mucopoly-saccharides and hyaluronic acid.
It’s a hydrophilic gel which become ‘’fluid’’ when protein coagulates.
Reasons for coagulation of proteins could be,
• Advancing senile age
• Degenerations, e.g. as in high myopia
• Chemical and mechanical trauma
Internal limiting membrane on inner surface of retina separate it from vitreous. There is potential space ‘subhyaloid space’ between two.


Figure 1 structures of vitreous
Vitreous attachments
1. Anteriorly to the lens and ciliary epithelium in front of ora serrata. Part of vitreous about 4mm across ora serrata is called as ‘base of vitreous’. Here, attachment is strongest.
2. Posteriorly to the edge of optic disc and macula lutea (foveal region) forming ring shaped structure around them.


Figure 2 vitreous attachments
Age changes in Vitreous
Vitreous undergo certain physical and biochemical changes with aging.
1. At birth_ the Cloquet’s canal runs straight from lens to optic disc. It contains primary vitreous.
2. In young persons_ vitreous gel is homogenous but its fibers become coarse with process of advancing age.
3. In old age and high myopes_ secondary vitreous liquified (syneresis) and shrinks, producing a vitreous detachment, vitreous and retinal hemorrhage and retinal break.





Figure 3 Vitreous at birth Figure 4 Vitreous in young adults.
Figure 5 vitreous detachment in old age


Vitreous Hemorrhage

Vitreous hemorrhage is the extravasation, or leakage, of blood into the areas in and around the vitreous humor of the eye.
TYPES
There are two types of vitreous hemorrhage.
1. Peripheral or subhyaloid hemorrhage _ occurs between retina and vitreous.
Blood remains fluid, red in color
Blood moves with gravity forming boat-shaped figure in macular area.

Figure 3 subhyaloid hemorrhage

2. Intravitreal hemorrhage_ the hemorrhage may get absorbed or degenerate to form a white fibrous tissue mass.
Etiology
Common causes of vitreous hemorrhage are;
i. Trauma_ by contusion or penetrating injury
ii. Vitreous retraction_ vitreous fibrous bands or membrane retraction
iii. Eale’s disease_ due to retinal vasculitis and periphlebitis
iv. Blood dyscrasias_ leukemia, sickle cell anemia, purpura.
v. Diabetes mellitus_ common in diabetic proliferative retinopathy
vi. Central retinal vein thrombosis
vii. Malignant hypertension_ often results in large intravitreal hemorrhage.
Symptoms
I. Black spots or clouds maybe seen in front of eye.
II. Impaired vision maybe up to perception of light.
Signs
1. Fundus examination
a) Faint or no red reflex seen
b) Grey opacities maybe present in vitreous

Figure 4 (A) Fundus exami

1. VITEROUS
Attachments, age changes, vitreous hemorrhage, Vitreous Detachment
MARYAM FIDA

Optometry and orthoptics

Vitreous

2. Vitreous
Vitreous is an inert, avascular, transparent, jelly like structure.
Serve as one of refractive media of the eye and has optical functions.
It gives structural integrity to eye and provide nutrients to the lens, ciliary body and retina.
Constitute 80% volume of the eye.
Contain collagen fibrils, mucopoly-saccharides and hyaluronic acid.
It’s a hydrophilic gel which become ‘’fluid’’ when protein coagulates.
Reasons for coagulation of proteins could be,
 Advancing senile age
 Degenerations, e.g. as in high myopia
 Chemical and mechanical trauma
Internal limiting membrane on inner surface of retina separate it from vitreous. There is
potential space ‘subhyaloid space’ between two.


Figure 1 structures of vitreous
Vitreous attachments

3. 1. Anteriorly to the lens and ciliary epithelium in front of ora serrata. Part of vitreous
about 4mm across ora serrata is called as ‘base of vitreous’. Here, attachment is
strongest.
2. Posteriorly to the edge of optic disc and macula lutea (foveal region) forming ring
shaped structure around them.


Figure 2 vitreous attachments
Age changes in Vitreous
Vitreous undergo certain physical and biochemical changes with aging.
1. At birth_ the Cloquet’s canal runs straight from lens to optic disc. It contains primary
vitreous.
2. In young persons_ vitreous gel is homogenous but its fibers become coarse with process
of advancing age.
3. In old age and high myopes_ secondary vitreous liquified (syneresis) and shrinks,
producing a vitreous detachment, vitreous and retinal hemorrhage and retinal break.

4. Figure 3 Vitreous at birth Figure 4 Vitreous in young adults.

Figure 5 vitreous detachment in old
age


Vitreous Hemorrhage

Vitreous hemorrhage is the extravasation, or leakage, of blood into the areas in and
around the vitreous humor of the eye.
TYPES
There are two types of vitreous hemorrhage.
1. Peripheral or subhyaloid hemorrhage _ occurs between retina and vitreous.
Blood remains fluid, red in color
Blood moves with gravity forming boat-shaped figure in macular area.

Figure 3 subhyaloid hemorrhage

2. Intravitreal hemorrhage_ the hemorrhage may get absorbed or degenerate to
form a white fibrous tissue mass.
Etiology

5. Common causes of vitreous hemorrhage are;
i. Trauma_ by contusion or penetrating injury
ii. Vitreous retraction_ vitreous fibrous bands or membrane retraction
iii. Eale’s disease_ due to retinal vasculitis and periphlebitis
iv. Blood dyscrasias_ leukemia, sickle cell anemia, purpura.
v. Diabetes mellitus_ common in diabetic proliferative retinopathy
vi. Central retinal vein thrombosis
vii. Malignant hypertension_ often results in large intravitreal hemorrhage.
Symptoms
I. Black spots or clouds maybe seen in front of eye.
II. Impaired vision maybe up to perception of light.
Signs
1. Fundus examination
a) Faint or no red reflex seen
b) Grey opacities maybe present in vitreous

Figure 4 (A) Fundus examination revealed hemorrhage of the retinal vein (arrow). (B) Retinal hemorrhage spontaneously
disappeared in 1 week after the discontinuation of regorafenib treatment.
2. Slit-lamp examination
Fresh blood or clotted blood is seen in vitreous.

Figure 5 large intravitreal hemorrhage
Vitreous Detachment

6. A vitreous detachment is a condition in which vitreous shrinks and separates from the
retina.
Types of detachment
1. Posterior vitreous detachment (PVD)
Separation of cortical vitreous from retina anywhere posterior to vitreous base
Synchysis_ associated vitreous liquification
Syneresis_ collapse of vitreous due to collection of synchytic fluid between
posterior hyaloid membrane and internal limiting membrane of retina.
Incidence
a) Common above age of 65 years
b) May occur in eyes with senile liquefaction with development of a hole in posterior
hyaloid membrane, e.g. aphakia, high myopia.
Symptoms
 Photopsia or flashes of light
 Floaters seen
Signs
 Biomicroscopic examination show collapsed vitreous behind lens.
 There is optical clear space between detached posterior hyaloid phase and
retina.
 An annular opacity (Weiss rings or Fuch’s ring) ring shaped detachment of
vitreous to optic disc indicate PVD.

Figure 6 1Posterior vitreous detachment (PVD)

2. Detachment of vitreous base and Anterior vitreous
Usually occur after blunt trauma.

7. Maybe associated vitreous hemorrhage, anterior retinal dialysis and dislocation
of lens.















































































MULTIPLE CHOICE QUESTIONS
1) Hyaluronic acid is found in?
a. Vitreous humor
b. Synovial fluid
c. Cartilage
d. Cornea
2) The most common cause of vitreous hemorrhage in adults is?
a. Retinal hole
Figure 7 Diagram illustrating the concept of dynamic vitreoretinal traction after posterior vitreous detachment and how this
generates a flap-tear or an operculated tear. In contrast with a dialysis the vitreous remains attached and there is no posterior
vitreous

8. b. Trauma
c. Hypertension
d. Diabetes
*(trauma is most common cause of vitreous hemorrhage in young adults)
3) Black floaters in a diabetic patient indicate?
a. Vitreous hemorrhage
b. Maculopathy
c. Vitreous infarction
d. Post vitreous detachment
4) The Cortical Vitreous (differing relative density) does not cover what 2 sites?
a) Ora serrata, fovea
b) Fovea, Optic nerve head
c) Posterior pole, Optic nerve head
d) Peripheral retina, fovea
5) Order the Vitreous attachments from STRONGEST to WEAKEST
a) Vitreous base, optic nerve head, posterior lens surface, retinal vessels,
macula
b) optic nerve head, posterior lens surface, macula, retinal vessels, Vitreous
base
c) Vitreous base, posterior lens surface, optic nerve head, macula, retinal
vessels
d) posterior lens surface, macula, retinal vessels, Vitreous base, optic nerve
head.
6) Which zone of embryologic origin forms the hyaloid artery and its branches (vasa
hylodea propria)?
a) Secondary vitreous
b) Primary vitreous
c) Tertiary vitreous
d) Medullary vitreous
7) Ora serrata:
a) forms the boundary between the retina and the
ciliary body
b) is closer to the Schwalbe's line temporally than nasally
c) forms part of the pars plana
d) does not contain photoreceptors
e) is loosely adherent to the vitreous
*(forms boundary b/w retina and pars plana, contain photoreceptors,
attach firmly to vitreous, and forms base of vitreous)
8) bleeding between retina and vitreous is _____? In which blood remains fluid, red
in color and form boat-shaped figure in macular area.
a) Vitreous loss

9. b) Inflammation of vitreous
c) Subhyaloid hemorrhage
d) Intravitreal hemorrhage
*(white fibrous tissue forms in intravitreal hemorrhage.)

9) Incidence of vitreous detachment is more likely
a) In adulthood
b) Congenital
c) Below 5-8 years
d) Above 65 years
10) Separation of _____ vitreous from retina is PVD?
a) Apical
b) Basal
c) Cortical
d) Apex and cortex