YAG Laser Vitreolysis of Symptomatic Vitreal Floaters

Vitreous fluid, containing 95% water, fills the space behind the lens. Its gelatinous consistency is due to the presence of hyaluronic acid, mucopolysaccharide and collagen fibers. With age, the collagen aggregates into parallel bundles, bound by cross links, leaving the pockets of liquid in the glass body. This redistribution is referred to as syneresis, which is found in 90% older than 40 years. After liquefaction, the vitreous enters the retroviral space and separates the posterior hyaloid membrane from the retina. When separating from the optical disk it forms an annular formation (Weiss ring) in front of the optical disc. These agglomerated collagen bundles (opacities) disperse the photons of light and are perceived by the patients as a "gray silhouette-like artifact". Two major interventions for these symptoms include Nd: YAG laser vitreolysis and vitrectomy. The less invasive method Nd: YAG laser increases the temperature of the opacity thus vaporizing them to smaller fragments that are easier to sediment onto the bottom of the vitreous cavity thereby relieving the symptoms.