Vitrectomy is a microsurgical procedure in
which specialized instruments and techniques
are used to repair retinal disorders, many
of which were previously considered
inoperable. The initial step in this
procedure is usually the removal of the
vitreous gel through very small (~1.4mm)
incisions in the eye wall, hence the name "vitrectomy".
The vitreous is removed with a miniature
handheld cutting device and replaced with a
special saline solution similar to the
liquid being removed from the eye. A high
intensity fiberoptic light source is used to
illuminate the inside of the eye while the
surgeon works. The surgeon uses a
specialized operating microscope and contact
lenses, which allow a clear view of the
vitreous cavity and retina at various
magnifications. The procedure is performed
in an operating room under local or
(occasionally) general anesthesia. It can
often be done as an ambulatory procedure.
Although vitrectomy procedures are sometimes
performed through incisions made near the
front of the eye, most vitreoretinal
surgeons enter the globe through a part of
the eye known as the pars plana. This is why
the procedure is often referred to as a
trans pars plana vitrectomy (TPPV). Entering
the eye through this location avoids damage
to the retina and the crystalline lens.
Pars plana vitrectomy is used to treat
many different retinal disorders including
those listed below (more information on
some of these topics can be found elsewhere
in our patient information section):
1. Proliferative diabetic retinopathy
(including vitreous hemorrhage)
2. Macular hole
3. Macular pucker (Epiretinal membrane)
4. Complicated, tractional or recurrent or
retinal detachment
5. Intraocular infections (endophthalmitis)
6. Intraocular foreign body
7. Retained lens material or dislocated lens
implants following cataract surgery
8. Giant retinal tears
9. Traumatic eye injuries
Surgeon's view during vitrectomy surgery
During vitrectomy surgery, the retinal
surgeon may use a variety of special
techniques to achieve the desired results,
including:
Intraocular gases (usuallyeither
perfluropropane (C3F8) or sulfur
hexafluoride (SF6)) when mixed with sterile
air have the property of remaining in the
eye for extended periods of time (up to two
months). They are eventually replaced by the
eyes own natural fluid. Gas is useful for
flattening a detached retina and keeping it
attached while healing occurs. Gas injection
is also used to close macular holes. It is
frequently necessary to maintain a certain
head position following surgery when gas is
used. Vision in a gas filled eye is usually
rather poor until at least 50% of the gas is
absorbed. Possible complications of
intraocular gas include progression of
cataracts and elevated eye pressure
(glaucoma). It is unsafe to fly in a plane
while gas remains in the eye.
Silicone oil is sometimes used instead of
gas to keep the retina attached
postoperatively. Silicone remains in the eye
until it is removed (often necessitating a
second surgery at a later date). This
technique is advantageous when long term
support ("tamponade") of the retina is
required, for instance in the repair of very
complicated retinal detachments. Unlike gas,
patients are still able to see through clear
silicone oil. Positioning is less critical
with silicone oil, therefore, it may be used
in patients unable to position
postoperatively (i.e. children). Like gas,
silicone oil can promote cataracts, cause
glaucoma, and may damage the cornea.
Endophotocoagulation is the use of laser to
treat intraocular structures. This modality
is often used to treat retina tears in the
setting of retinal detachment.
Endophotocoagulation is frequently used to
treat proliferative diabetic retinopthy as
well.
Microsurgical instruments such as forceps,
scissors and picks may be used to manipulate
intraocular structures such as in the
removal of scar tissue and foreign bodies.
Literally hundreds of vitrectomy instruments
are available to assist in different
surgical maneuvers. Most of these
vitreoretinal tools have a diameter of less
than 1mm, making them some of the most
precise and finely crafted instruments in
the world today.
Endoscopy allows the surgeon to view the
inside of the eye on a television monitor
while treating intraocular structures. It is
a helpful technique when the cornea or lens
are cloudy and do not allow a clear view
through the operating microscope.
Scleral buckling is sometimes combined with
a vitrectomy procedure to add additional
support to the re-attached retina
Lensectomy is the removal of the eye's
crystalline lens during a vitrectomy
procedure. This is sometimes performed when
there is a cataract (clouding of the lens)
which prevents the surgeon from adequately
visualizing the internal structures. A
lensectomy may also be necessary to gain
access to and remove scar tissue during
complicated retinal detachment or diabetic
retinopathy procedures. The natural lens can
be replaced with a clear lens implant at a
later date or during the same surgical
procedure. Lensectomy is usually performed
using high frequency ultrasound (phacoemulsification)
similar to routine cataract surgery.
Vitrectomy surgery is a major medical
advance which allows us to treat retinal
diseases and prevent vision loss for
patients who, in previous years, may have
gone blind without this technique. A
vitrectomy procedure usually takes about 1-2
hours but may take longer in complex cases
or when combined with a scleral buckle or
lensectomy.