Posterior vitreous detachment

• occurs when the vitreous separates from the retina
  
  
• present in approximately 65 per cent of people over the age of 65 (1)
  
  
• syneresis (liquefaction of the vitreous) occurs as part of ageing, in myopia, following ocular surgery or ocular trauma, and results with the formation of lacunae within the gel
  • often these lacunae coalesce with the posterior vitreous face, and the fluid egresses into the preretinal space; the posterior vitreous then separates from the retina resulting in posterior vitreous detachment
    • age-related posterior vitreous attachment is an insidious, chronic process
      
      
      • evolves over a prolonged period before vitreopapillary separation (2)
      • generally asymptomatic
        • however its early stages may be complicated by a variety of macular and optic disc problems - the symptomatology is in part determined by the size and strength of the residual vitreoretinal adhesion
          
• Fibrocellular material may remain on the posterior vitreous face from where the vitreous was more tightly adherent to the edge of the optic disc. This condition may result in floaters which are often described as either a circle, ovoid or a bent line, depending on the completeness of the detachment
  
  
• ophthalmoscopy may reveal a Weiss' ring at the site of fibrocellular material
  
  
• in general, the posterior vitreous detachment remains as described, and results in no further harm to the retina. The patient gradually becomes accustomed to his floaters
  
  
• occasionally photopsia (an ocular flash) may occur if the vitreous separation exerts traction on the retina
  
  
• a vitreous haemorrhage may occur if the detachment involves a retinal vessel
  
  
• a retinal detachment occurs if the vitreous fluid passes through a retinal break resulting in separation of the retina from the underlying pigmented epithelium

Reference:

• Practitioner (1998), 242, 302-4.
• Johnson MW; Posterior vitreous detachment: evolution and complications of its early stages. Am J Ophthalmol. 2010 Mar;149(3):371-82