A vitrectomy is a procedure to improve sight by removing the cloudy, gel-like substance (vitreous humor), and sometimes blood, from the center of the eye. When the vitreous is removed, the eye regains its transparency, allowing light to travel to the retina and restore vision.

In a healthy eye, the vitreous is a clear, gel-like substance that fills the center of the eye and helps give it form and shape. However, problems that affect the back of the eye may require the vitreous to be surgically removed. Retinopathy is the most common cause of vitreous disorders in people with diabetes.

Vitrectomy is performed by making incisions in the sclera (the tough, white fibrous tissue covering the eye) and cutting or suctioning out the vitreous gel. Once this is completed, the surgeon may complete one or more of the following:

• Seal off leaky blood vessels using a laser procedure known as endophotocoagulation
  
  
• Remove scar tissue from the retina
  
  
• Flatten areas where the retina has detached from the eye wall
  
  
• Repair tears or holes in the retina or macula (the central area of the retina responsible for sharp vision)

Vitrectomy can restore vision in some patients, according to the U.S. Centers for Disease Control and Prevention (CDC).