Vitrectomy is a surgical procedure undertaken by a retinal expert where the vitreous humor gel that fills the eye cavity is removed to provide better access to the retina. This allows for a variety of repairs, including the removal of scar tissue, laser repair of retinal detachments and treatment of macular holes. Once surgery is complete, saline, a gas bubble or silicone oil may be injected into the vitreous gel to help hold the retina in position.

Posterior Pars Plana Vitrectomy

The vitreous or vitreous humor is thought to serve as a framework or support for the layers of a newborn’s eye during development. In normal eyes, the vitreous is crystal clear throughout adulthood and fills the eye from the front or anterior (iris-lens) to the back or posterior (optic nerve). This area comprises two-thirds of the volume of the eye and is called vitreous cavity, which along with the retina, the retinal pigment epithelium, choroid, and sclera, make up the posterior segment.

A vitrectomy performed for diseases of the posterior segment is called a posterior or pars plana vitrectomy. This kind of vitrectomy is performed by a retina specialist.

Anterior Vitrectomy

In rare cases, the vitreous gel comes through the pupil into the anterior (front) chamber of the eye. This can happen:

• Following eye trauma (injury)
• During complex cataract, cornea, or glaucoma surgery
• As a result of lens problems

Because leaking vitreous gel can lead to future problems, an anterior vitrectomy may be performed to minimize risk and to promote visual recovery. Almost all ophthalmologists have received eye surgery training in their residency and can perform an anterior vitrectomy.

The retina surgeon chooses the best equipment to use in each case from a wide variety of vitrectomy instrumentation. Since the first vitrectomies were performed in the 1970s, the trend has been toward smaller and thinner microsurgical equipment.

Many vitrectomy procedures can now be performed with self-sealing, sutureless (no-stitch) incisions approximately one half of a millimeter in size, which is about the width of an eyelash. Although it has some limitations, small-gauge vitrectomy surgery is generally considered more comfortable than surgery with larger instruments and offers faster visual recovery in many cases.

Unless the patient is in poor health or has severe disease, nearly all vitrectomies are outpatient procedures performed either in a hospital or in a dedicated ambulatory surgery center; they involve little or no pain and require only minimal anesthesia.

An IV, EKG, blood pressure, and oxygen sensors are in place to monitor the patient’s vital signs and health. In the operating room, a formal time-out procedure is used as a safety measure. This procedure verifies that the team has the correct patient, procedure to be performed, and eye to be operated on. The information is confirmed by surgical, nursing, and anesthesia staff.

The eye is anesthetized (numbed) so the patient is comfortable during the procedure. IV sedation (commonly called twilight sleep), or in rare cases general anesthesia, may be used for additional relaxation.

The eye is prepared with antiseptic solution and a sterile drape is applied. An eyelid speculum is used to keep the operative eye open. The other eye is covered and protected. Patients generally close their non-operative eye and rest during the surgery.

Typically, the dilated eye is entered through the pars plana, a “safe zone” in the white part of the eye or sclera; hence this procedure is called a pars plana vitrectomy. A surgical microscope with a special lens allows a wide view of the inside of the eye as well as a magnified and detailed view. (Figure 1). The surgeon uses a vitrectomy probe (vitrector) to cut and delicately remove the gel-like vitreous.

Complications of surgery are rare, but include infection, bleeding, high or low eye pressure, cataract, retinal detachment, and loss of vision.

Vitrectomy or vitreous surgery can treat a number of conditions. Surgery is indicated only when these 4 conditions are met:

• The findings are causing or threatening vision loss
• The severity of the condition or natural history make spontaneous or non-surgical healing unlikely
• The potential benefits outweigh the potential risks of surgery
• The patient understands the risks and benefits of treatment, as well as alternatives

The goals of surgery are:

• To treat the pathology (abnormal condition) causing visual loss
• To reduce the likelihood of recurrence
• To minimize the risk of complications