Primary Retinal Detachment

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5 Vitrectomy for the Primary Management of Retinal Detachment
base, a low encircling scleral buckle is used to reduce vitreous traction
that inherently cannot be removed. A scleral buckle should
also be used to support inferiorly located retinal breaks. In general,
scleral buckling is not needed if the vitreous attachments can be
completely relieved around the retinal break. These are usually
retinal tears that are located posterior to the vitreous base.
A 2.0-mm or 2.5-mm encircling band with low to moderate elevation
can be placed to support the vitreous base region.
After preplacing the scleral buckle, the vitrectomy proceeds
with removal of the central vitreous. If the retinal detachment is
very bullous and close to the posterior surface of the lens, it is possible
to drain subretinal fluid before entering with the vitrectomy
instruments. In my experience, this has never been required. In
cases where the retinal detachment is bullous or the detachment
threatens to involve the macula, it is helpful to use some perfluorocarbon
liquid to flatten the posterior retina.Approximately 1–1.5 ml
of liquid is used, and this can prevent the retinal detachment from
becoming more bullous or a further detachment anteriorly due
to the introduction of the surgical instruments. The vitrectomy
instrument is set using high cutting rates (2,000–2,500 cuts/min)
with relatively low aspiration settings to reduce the chance of
causing iatrogenic retinal breaks during the vitrectomy. At this
point, a wide-field contact lens is used to examine the retina and to
localize the retinal breaks. In most instances, the breaks are readily
appreciated, but occasionally, the retinal breaks will be found after
scleral depression and shaving of the basal vitreous. Occasionally
retinal breaks can also be seen by observing the “schlieren” from
subretinal fluid passing through the retinal break as additional
perfluorocarbon liquid is injected.
It is important to excise much of the peripheral vitreous at the
vitreous base to reduce remaining anterior tractional forces on
the retinal break. It is contraction of residual basal vitreous that
leads to anterior foreshortening of the retina. After careful scleral
depression and peripheral vitreous excision, it may be helpful to
lightly mark the retinal breaks with endodiathermy so that they