Vitreous Flashcards
(16 cards)
main function of the vitreous body?
Transmits light to the retina.
Provides mechanical support to the retina and lens.
Acts as a shock absorber protecting the retina from trauma.
Contributes to the refractive index of the eye. (1.33)
composition of the vitreous body?
he vitreous is made up of collagen fibers, hyaluronic acid, and water.
It consists of a gel-like substance in the center and a denser cortex near the retina and lens.
Where is the vitreous body located within the eye?
The vitreous body fills the posterior segment of the eye, between the lens and the retina.
What are the main components of the vitreous body?
A:
Vitreous cortex: The dense outer layer containing collagen fibers and hyalocytes.
Gel (Main body): Contains hyaluronic acid and chondroitin sulfate for flexibility and hydration.
Vitreous base: The area where the vitreous is strongly attached to the ora serrata and ciliary body.
What is Cloquet’s canal and what is its function?
Cloquet’s canal is a remnant of the hyaloid artery, running from the optic disc to the posterior lens capsule.
It serves as a pathway for the fetal hyaloid artery and typically remains visible in adults as a curved channel.
How does the vitreous body change with age?
Vitreous syneresis occurs, causing the vitreous to become more liquid and less gel-like.
Collagen fibers aggregate, forming floaters.
The gel shrinks, and areas of the vitreous become more liquid.
What is posterior vitreous detachment (PVD)?
PVD occurs when the vitreous gel separates from the optic disc.
It is common with aging and can lead to symptoms like flashes of light and floaters.
What are the clinical signs associated with vitreous aging?
Floaters: Due to the breakdown of the gel and the presence of collagen clumps in the vitreous.
Posterior vitreous detachment (PVD): Separation of the vitreous from the retina, which may lead to retinal tears or detachment.
Weiss ring: A large floater that appears at the optic disc margin, characteristic of PVD.
What is Shafer’s sign and what does it indicate?
Shafer’s sign refers to pigment cells (often called tobacco dust) in the vitreous, indicating a retinal tear or break.
It is a diagnostic sign for retinal detachment.
What is asteroid hyalosis?
Asteroid hyalosis is the presence of calcium and lipid particles suspended in the vitreous.
It is typically benign but can cause floaters.
What is synchysis scintillans?
Synchysis scintillans is a condition where cholesterol crystals are suspended in the vitreous, often seen in association with uveitis, diabetic retinopathy, or vitreous hemorrhage.
What is vitreous hemorrhage and what are its causes?
Vitreous hemorrhage is the presence of blood in the vitreous cavity, typically caused by retinal diseases such as diabetic retinopathy or trauma.
Symptoms include floaters and a significant loss of vision.
What are the potential complications of a posterior vitreous detachment (PVD)?
Retinal tears: Traction on the retina can cause a tear, leading to retinal detachment.
Macular edema: Fluid leakage from retinal tears can cause swelling in the macula, leading to visual distortion.
What is the role of the vitreous body in maintaining eye shape?
The vitreous body helps maintain the globe’s spherical shape by exerting pressure on the retina and lens, ensuring proper alignment and supporting the eye’s structural integrity.
How can optometrists manage patients with floaters?
Observation: Most floaters are benign and require monitoring.
Referral: If floaters are associated with flashes of light or sudden vision loss, retinal tears or detachment must be ruled out.
Laser treatment: In rare cases, laser therapy may be used to reduce large floaters that significantly impair vision.
What is vitreous traction and how can it affect the retina?
Vitreous traction occurs when the vitreous gel pulls on the retina, potentially causing retinal tears or macular holes, which can lead to vision loss if untreated.
