Vitrectomy

Vitrectomy
Intervention
Three port 23-gauge vitrectomy
ICD-9-CM	14.73-14.74
MeSH	D014821
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Vitrectomy is surgery to remove some or all of the vitreous humor from the eye. Anterior vitrectomy entails removing small portions of the vitreous humor from the front structures of the eye — often because these are tangled in an intraocular lens or other structures. Pars plana vitrectomy is a general term for a group of operations accomplished in the deeper part of the eye, all of which involve removing some or all of the vitreous humor — the eye's clear internal jelly.

Vitrectomy was originated by Robert Machemer with contributions from Thomas M. Aaberg, Sr in late 1969 and early 1970. The original purpose of vitrectomy was to remove clouded vitreous humor — usually containing blood.

The success of these first procedures led to the development of techniques and instruments to remove clouding and also to peel scar tissue off the light sensitive lining of the eye — the retina — membranectomy, to provide space for materials injected in the eye to reattach the retina such as gases or liquid silicone, and to increase the efficacy of other surgical steps such as scleral buckle.

The development of new instruments and surgical strategies through the 1970s and 1980s was spearheaded by surgeon/engineer Steve Charles, M.D. More recent advances have included smaller and more refined instruments for use in the eye, the injection of various medications at the time of surgery to manipulate a detached retina into its proper position and mark the location of tissue layers to allow their removal, and for long term protection against scar tissue formation.

Additional surgical steps involved as part of modern vitrectomy surgeries may include:

Membranectomy – removal of layers of unhealthy tissue from the retina with minute instruments such as forceps (tiny grasping tools), picks (miniature hooks), and visco-dissection (separating layers or tissue with jets of fluid.)

Fluid/air exchange – injection of air into the eye to remove the intraocular fluid from the posterior segment of the globe while maintaining intraocular pressure to temporarily hold the retina in place or seal off holes in the retina. The air pressure is temporary as the posterior segment will soon re-fill with fluid.

Air/gas exchange – injection of gas, or more typically mixed gas and air, into the posterior segment of the globe. Typical gases used are perfluoropropane or sulfur hexafluoride. The gases are mixed with air to neutralize their expansive properties to provide for a longer acting (than air alone) retinal tamponade. The retinal tamponade acts to hold the retina in place or temporarily seal off holes in the retina. The mixed gases disappear spontaneously once they have accomplished their purpose and the posterior segment re-fills with fluid.