This presentation describe the vitreous for undergraduate students

1. THE
VITREOUS
Abdelmonem
Hamed, M.D.
Professor of Ophthalmology
Benha College of Medicine
Fellow of Baylor College of Medicine, USA

2. The vitreous is
 an inert,
 avascular,
 transparent, jelly –
like structure which
serves only optical
functions.
 It consists of a
delicate framework
of collagen and
hyaluronic acid.
Wight: 4gm
Volume: 4ml

3. Attachments:
 It is attached
anteriorly to
the lens and
ciliary
epithelium.
 It is known as
the "vitreous
base".

4. Attachments:
 It is attached posteriorly to the edge of the
optic disc and macula lutea.

5. Function:
 The vitreous forms one of the
refractive media of the eye. (RI
1.33)
 RI of H2o = 1.369
 RI of air = 1 .00
 RI=Measure of the refraction
of a beam of light on entering
a denser medium
Nutrition :
It derives nutrition from the surrounding structures like
choroids, ciliary body.

6. OPACITIES IN THE VITROUS
 Etiology:
 Development causes:The opacities are
usually located in the Cloquet's canal.
 Degenerative causes.

7. OPACITIES IN THE VITROUS
 Vitreous:
is optically clear
structure
 Pseudo membranes
and pseudo fibers
appearing as moving
folds (Vit. floaters, or
Muscae volitantes)
Weiss’ ring

8. Asteroid hyalosis:
 Spherical, white bodies of
calcium soaps resembling
snowball.
 It is asymptomatic
therefore no treatment is
required.
 A pars plana vitrectomy
may be considered if
vision is markedly
reduced.

9. Synchysis scintillans:
 deposition of highly
refractive cholesterol
crystals in the vitreous.
 Golden shower is seen
during the movements of
the eye.
 No treatment is
indicated.

10. Other causes of vit.
opacities:
 High myopia.
 Retrolental fibroplasia.
 Wagner's disease.
 Ehlers- Danlos syndrome
 Marfan's syndrome
 Chronic cyclitis.
 Diabetes and Eale's disease
 Neoplasm.
 Amyliodosis

11. Q: Can vitreous degeneration be
treated?
A: Molecular bonds of the clear
vitreous cannot be restored after
vitreous collapse = no medical ttt

12. VITAMINS
Antioxidants may
retard the
denaturation of protein

13. Treatment of vitreous
opacitiec
1.YAG laser
2.Vitrectomy

14. NEODYMIUM-YAG LASER
 infrared spectrum
 focused beam
 energy 4 - 6 milli
joules
 200 - 600 shots total
 1 - 3 treatments
 Photodisruption
LASER SURGERY

15. COMPLICATIONS
 elevated intraocular pressure
 chroidal micro hemorhage
 retinal detachment
 cataract

16. VITREOUS BANDS AND MEMBRANES
 They consist of hyalocytes, fibrocytes and
endothelial cells of the capillaries.
 They cause oedema, haemorrhage and hole
formation in the retina. Why?
 This is may be followed by RD.
 TTT: PP vitrectomy.

17. PERSISTENT HYPERPLASTIC PRIMARY
VITREOUS
Etiology:
 failure of primary vitreous
structure to regress after
birth.
Symptoms:
 White reflex is seen in the
papillary area.
 it may be associated cataract,
glaucoma, microphthalmos,
intraocular haemorrhage.

18. PERSISTENT HYPERPLASTIC PRIMARY
VITREOUS
Diagnosis:
 It is diagnosed by CT.
Treatment:
 Lensectomy and
vitrectomy

19. VIREOUS HAEMORRHAGE
Types:
There are two types of vitreous haemorrhage:
1. Preretinal or subhyaloid haemorrhage:
1. The haemorrhage occurs between the retina and the
vitreous.
2. The blood remains fluid, red in colour and moves
with gravity .
2. IntraVitreal haemorrhage:The haemorrhage
may get absorbed or degenerate to form a white
fibrous tissue mass.

20. Intravitreal haemorrhage
subhyaloid haemorrhage

21. Etiology:
1. Trauma
2. Vitreous traction.
3. Diabetes mellitus.
4. Central retinal vein thrombosis.
5. Eale's disease: It is due to retinal vasculitis
and periphlebitis.
6. Malignant hypertension
7. Blood diseases: Leukemia, sickle cell
anaemia, etc.

22. Symptoms:
1. Black spots or cloud
may be seen in front
of the eye.
2.There is impaired
vision. It may be
reduced to
perception of light.

23. Signs:
1. Fundus examination:
i. No red reflex is seen.
ii. Grey opacities may be
present in the vitreous.
2. Slit-lamp examination: Fresh
blood or clotted blood may
be seen in the vitreous.

24. Complications:
1. Complicated cataract may occur.
2. Retinal atrophy may be present due to
haemosiderosis.
3. Retinal detachment may occur due to
organized fibrous tissue bands…..TRACTION

25. Treatment:
1. Bed-rest with elevation of head.
2. Photocoagulation: It is done if new vessels or
retinal tears are seen.
3.Vitrectomy: It is done after 3 months if no
visual improvement

26. VITREOUS LOSS
Definition:
 Herniation of vitreous
only in the anterior
chamber or outside the
eye.
Etiology:
Accidental vitreous loss
may occur during surgery
on the lens, cornea and
iris.

27. Signs:
1. Corneal oedema due
to endothelium touch.
2. Updrawn pupil due to
attachment of
vitreous between the
papillary margin and
wound.
3. Macular oedema.
4. Aphakic glaucoma
due to papillary block.

28. Treatment:
Anterior vitrectomy
 By vitrectomy machine, or
 By vitreous scissors is performed through a large
corneal section .

29. VITREOUS INFLAMMATION
 Vitreous is an excellent culture medium for
the growth of bacteria and fungus leading to
endophthalmitis and vitreous abscess
formation.

30. Signs of endophthalmitis
 The presence ofWBCs lead to formation of
fibrous connective tissue >>>>>>retinal
detachment due to contraction.
 TTT:
 Medical
 IO injection
 Vitrectomy

31. VITRECTOMY
 Excision and replacement of the vitreous is
known as vitrectomy.

32. Indications for vitrectomy:
1. Persistent vitreous opacity.
i. Haemorrhage.
ii.Vitreous membrane and bands.
iii. Preretinal membranes.

33. Indications for vitrectomy:
2. Complications of cataract extraction:
i. Loss of vitreous.
ii.Vitreous touch with bullous keratopathy.
iii. Incarceration of vitreous in wound.
iv. Malignant glaucoma.
v. Removal of intraocular lens or nucleus
from the vitreous cavity.
3. Endophthalmitis with vitreous abscess.

34. Indications for vitrectomy:
4.Trauma:
i. Intraocular foreign body.
ii. Subluxated or dislocated lens.
5. Complicated retinal detachment
i.Vitreous traction by fibrovascular bands.
ii. Gaint retinal tear.
iii. Retinal dialysis.
6. Congenital cataract (lensectomy).
7. Persistent hyperplastic primary vitreous.

35. TYPES OF VITRECTOMY
 Anterior vitrectomy
 PP vitrectomy 3.5mm from limbus =
pars plana

36. VITREOUS SUBSTITUTES
 Liquid:
 Normal saline,
 BSS (balanced salt solution),
 silicone oil,
 sodium hyaluronate (Healon).
 Perfluorocarbon liquids (PFCL), etc.

37. VITREOUS SUBSTITUTES
 Gas:
a. Air.
b. Sulfur hexafluoride (SF6).
c. Perfluoro-propane (C3F8)
d. Octa-fluoro-cyclo-butane (C4F8).

38. Thank you
for your
attention
Abdelmonem.hamed@gmail.com