 The
hemispheres are used to begin the expansion of the soft tissues
of the superficial socket. The hemispheres are equipped with
suture holes to facilitate placement with or without tarsorraphy
sutures.
The Hemispheres are available in three sizes to accommodate
variation in each individual case and to carryout the expansion
process in multiple stages if necessary.
Surgical Techniques
Every case is different and therefore the application of
variations in surgical techniques may be required and must
account for previous treatment, etc.
In general, the tissue expansion protocol will normally begin
with the insertion of a hemispherical expansion device to
expand the socket and palpebral fissure.
Socket Expansion
A dry hemisphere of the appropriate size is fixated into
position within the lid fissure with the convex side of the
implant facing anteriorly. Once inserted, the device will
slowly expand the tissue by absorbing water from the tissue
space.
The material becomes increasingly softer and more fragile
as it absorbs water. Therefore the sutures are tied loosely
to provide play for expansion.
For example, the suture holes on the medium sized hemisphere
are 3mm apart when dry and are 10mm apart when fully expanded.
If a single suture is used, the soft tissue fixation points
should be separated to compensate for expansion. A non absorbable
such as a 6-0 prolene is recommended.
An alternative suture technique is to use two interrupted
sutures fixated to the superior and inferior periosteum of
the orbital rim. This allows the device to expand outward
in the direction of the suture loops.
Tarsorraphy
One or two U-shaped non-absorbable tarsorraphy sutures may
be used to help retain the expander within the socket. The
temporary tarsorraphy sutures may be attached to silicone
pearls or silicone tubes to reduce the load on the sutures.
Eye drops may be used if the socket is too dry to expand
the material. This is intended to expand the soft external
tissues achieve more normal proportions for the eyelid margin.
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