Diseases of the vitreous body

The vitreous body is the transparent, gelatinous substance that fills the space of the eye between lens and retina. It allows light to pass from the lens to the retina and normally has enough mass to maintain the eyeball's spherical shape and counteract retinal detachment. This article covers the most common diseases of the vitreous body, including posterior vitreous detachment and vitreous hemorrhage.
Posterior vitreous detachment is the separation of the posterior vitreous cortex from the internal limiting membrane of the retina. Etiologies include age-related degeneration of the vitreous tissue, elongation of the ocular bulb, and eye injuries. Patients are usually asymptomatic, but may complain of floaters and photopsia. Vitreous detachment is confirmed on slit lamp examination. Asymptomatic individuals do not require treatment. Symptomatic individuals with retinal injury (e.g., retinal tears/holes, retinal detachment) require prompt treatment with, e.g., laser photocoagulation.
Vitreous hemorrhage is the extravasation of blood into the vitreous body and its adjacent structures. It can be caused by trauma and a variety of diseases, e.g., proliferative diabetic retinopathy, posterior vitreous detachment, and tumors. Clinical features include painless sudden onset of unilateral floaters and/or visual loss. Slit lamp examination confirms the presence blood in the vitreous body. Initially, a wait-and-see approach is recommended, since the condition typically resolves spontaneously. However, if the retina is affected or severe disease progression occurs, vitrectomy is indicated.

• Definition: detachment of the posterior vitreous cortex from the internal limiting membrane of the retina
• Epidemiology: peak incidence between 45–65 years of age
• Etiology
  • Age-related degenerative liquefaction and collapse of the vitreous body (most common cause)
  • Myopia
  • Eye injury
  • Chorioretinitis
• Clinical features
  • Patients are usually asymptomatic
  • Photopsia with eye movements: perception of bright flashes of light
    • Caused by partially detached vitreous tissue pulling on the retina.
    • Differential diagnosis: scintillating scotoma in migraines
  • Floaters
• Diagnostics
  • Slit lamp examination: detached posterior surface of the vitreous becomes visible as thin irregular ring (Weiss ring)
• Treatment
  • Treatment is not necessary in patients without retinal injury and/or patients in whom symptoms resolve
  • Symptomatic patients with retinal injury require prompt treatment (see complication below)
• Complications
  • Retinal tears/holes
  • Rhegmatogenous retinal detachment
  • Vitreous hemorrhage

The sudden onset of floaters and/or the perception of flashes require urgent examination of the ocular fundus to rule out retinal injury!

• Definition: hemorrhage between the retina and the posterior vitreous membrane
• Etiology
  • Microangiopathy/neovascularization (e.g., in proliferative diabetic retinopathy)
  • Disorders of hemostasis and fibrinolysis
• Clinical features
  • Sudden onset of black opacities and/or visual loss
  • Hyphema
• Diagnostics:
  • Slit lamp examination
    • Well-demarcated boat-shaped hemorrhage in the posterior eye segment
    • Blood in the potential space between the internal limiting membrane and the retina
  • Ocular B-scan ultrasonography if blood completely obscures the posterior segment of the eye
• Treatment
  • Laser hyaloidotomy: opening of the vitreous body's hyaloid membrane → blood distribution by diffusion
  • Pars plana vitrectomy: surgical procedure in which the vitreous gel is removed from the eye by introducing the instruments through the pars plana

• Definition: persistent embryonic tissue, which blocks the light passing to the back of the eye
• Etiology
  • Failure of the embryonic primary vitreous and hyaloid vascular system to regress during gestation
• Symptoms / clinical features
  • Leukocoria
  • Reduced visual acuity up to complete loss of vision
  • Microphthalmia of the affected eye
  • Usually unilateral
• Diagnostics
  • Slit-lamp examination
    • Anterior type
      • Lens changes (clouded membrane → membranous cataract)
      • Vascularized whitish retrolental tissue
      • Ciliary body villi are displaced towards the center and are visible in the pupil
    • Posterior type: Retinal detachment and retinal dysplasia are possible
  • Ultrasonography: if posterior eye segments cannot be assessed properly due to clouding of the lens
• Treatment
  • Symptomatic treatment
• Complications
  • Aqueous fluid drainage disorder → glaucoma
  • Retinal detachment
  • Vitreous hemorrhage

Infants with leukocoria should be examined for the presence of life- or sight-threatening conditions, such as retinoblastoma.

Synchysis scintillans (cholesterolosis bulbi)

• Definition: degenerative liquefaction of the vitreous body with cholesterol deposits
• Epidemiology: very rare, onset usually in mid-adulthood
• Etiology: can result from chronic vitreous hemorrhage
• Clinical features
  • Usually asymptomatic
  • Floaters
• Diagnostics
  • Slit lamp examination: white floaters in the posterior chamber of the eye (snow-globe effect)
• Treatment: not indicated; may become necessary if complications occur
• Complications: advanced liquefaction → collapse of the vitreous body (see vitreous detachment)

Asteroid hyalosis (synchysis nivea)

• Definition: degenerative liquefaction of the vitreous body involving vitreous opacities due to deposits of fatty calcium salts
• Etiology
  • Unknown cause; associated with diabetes mellitus, hypercholesterolemia
• Clinical features
  • Usually asymptomatic
  • Unilateral floaters or vision loss may occur
• Diagnostics
  • Opthalmoscopy/slit lamp examination: multiple, whitish, bright, and round opacities
• Treatment
  • Not indicated (since typically asymptomatic)
  • Vitrectomy if vision is significantly impaired

Floaters (mouches volantes, flying flies)

• Symptoms
  • Perception of opacities of various sizes and shapes (e.g., points, lines, filamentous structures)
  • Move as the eyes move and across the visual field
  • More intense when looking at bright, homogeneous areas (e.g., when looking at the sky or white paper)
• Etiology
  • Degenerative processes in the vitreous humor (liquefaction, congestion)
  • Increased occurrence in posterior vitreous detachment, myopia
• Treatment
  • Usually not pathological, but often considered disturbing by the patient

Watch out if there is a severe increase in floaters or photopsia occurs simultaneously → risk of retinal tearing and retinal detachment!