Vitreous humor anatomy

• Vitreous humor is the transparent, jelly like visual media occupying the posterior 4/5 of eyeball
• Volume – 4ml
• Formed of randomly arranged collagen fibers with spheroidal macromolecules of hyaluronic acid in between

Parts of vitreous humor:

1. Cortical vitreous
   • The outer part of vitreous close to the retina posteriorly and the lens and ciliary body anteriorly
   • Arrangement of collagen fibers is denser
   • These fibrils condense to form a false anatomical membrane
     • anterior hyaloid membrane
       • in front of ora serrata
       • firmly attached to lens in young people and loosely attached in elderly
     • posterior hyaloid membrane
       • behind ora serrata
       • loosely attached to internal limiting membrane of retina at all ages
2. Body of vitreous (nucleus)
   • The inner zone of vitreous.
   • True biological gel
   • Less dense
   • Liquefactions first start here
   • Cloquet’s canal / hyaloid canal passes through the vitreous from the optic disc to posterior pole of lens
     • It contains the hyaloid artery of the fetus
     • It is of doubtful existence in adults

Attachments of vitreous

• Vitreous base
  • part  of vitreous which is most firmly attached
  • 4mm area across ora serrata
• Also attached around optic disc, fovea, posterior surface of lens (Hyaloidocapsular ligament of wieger)

Functions of vitreous

• Maintains shape of eyeball
• Maintains intraocular tension
• Nutritive function
• As a optically clear media for light to reach the retina