Definition

Vitrectomy is the surgical removal of the vitreous (transparent gel that fills the eye from the iris to the retina).

  Purpose

The bulk of the contents of the eyeball is a clear jelly-like substance that is susceptible to several afflictions that impair vision by damaging its transparency.

• Infections
• Injuries
• Bleeding, particularly from diabetic retinopathy.
• Blood vessels growing into the vitreous, again due to diabetes.

The retina is the light-sensitive membrane that receives images and transmits them to the brain. It covers the inside of the back of the eye. On occasion the retina will fall into the vitreous, a condition called retinal detachment. This may be due to disease in the vitreous that pulls the retina inward, small tears in the retina that allow liquid to seep behind it and push it forward, or injury to the eye that simply breaks the retina loose. It may be necessary to remove the vitreous in order to replace the retina and restore vision.

  Description

Using instruments suited for microscopic surgery, the ophthalmologist (eye surgeon) penetrates the eyeball, aspirates the vitreous, and replaces it with saline. The saline replaces the vitreous at a constant pressure in order to keep the eye from collapsing. Once the saline is in place, both eyes are patched. The procedure takes two to three hours to complete.

  Preparation

Because this is a major operation on the eye, the surgeon will perform a very extensive evaluation of both eyes. After looking inside with a variety of lenses, a CT, MRI, or ultrasound study may be needed. Immediately prior to the vitrectomy, the pupils will be dilated.

  Aftercare

Eye drops and antibiotics are administered, and eye rest is advised until healing is completed.

  Risks

Risks associated with vitrectomy are retinal detachment, bleeding, iatrogenic (medically caused) cataracts, and endophthalmitis (inflammation of the eyeball).

Normal results

Vision is restored to useful levels in two-thirds of patients.

   Key Terms:

Computed tomography (CT scan) Computerized method of creating images of internal organs using x rays. Diabetic retinopathy Disease that damages the blood vessels in the back of the eye caused by diabetes mellitus. Endophthalmitis Inflammation of the eyeball. Iatrogenic Inadvertently caused by medical treatment. Magnetic resonance imaging (MRI) Computerized method of creating images of internal organs using magnetic fields. Saline A salt solution equivalent to that in the body--0.9% salt in water.

   Resources:

Books

• O'Malley, Conor. "Vitreous." In General Ophthalmology. 13th ed. Ed. Daniel Vaughan. Stamford: Appleton & Lange, 1993.
• Sardegna, Jill, and T. Paul Otis. The Encyclopedia of Blindness and Vision Impairment. New York: Facts on File, Inc., 1990.