STRATEGIES AND INSTRUMENTATION
NEW INDICATIONS FOR INTRAOCULAR GAS
Michel Eid Farah, R. A. Costa, J. A. Cardillo (Sao Paulo)
1. Experimental Study
To determine the effectiveness of gas-mediated vitreous compression in
the management of experimental vitreous hemorrhage. A total of ten New
Zealand white rabbits received in the right eye a vitreous injection of
0.4 ml of autologous blood. After 24 hours of the vitreous hemorrhage
simulation six eyes were randomly assigned for treatment with a vitreous
injection of 0.2 ml of 100 % perfluoropropane (C3F8) gas (group A) and
four eyes acted as control and received a sham injection of equivalent
volume of balanced salt solution (group B). The gas-mediated vitreous
compression proved efficacy in the treatment of experimental vitreous
hemorrhage.
2. Clinical Studies
A close clinical relationship exists between vitreoretinal traction and
the pathogenesis of an idiopathic macular hole and macular edema. Tangential
and anteroposterior vitreous traction on the macula was the basis for
surgical induction of posterior vitreous detachment by vitrectomy. The
possibility of a pneumatic release of the vitreous traction has also been
discussed, but has never been assessed with optical coherence tomography.
This communication reports the treatment and follow-up of patients with
stage 2A macular hole and macular edema associated with anteroposterior
foveal traction confirmed by optical coherence tomography, who was treated
with a single intravitreous perfluoropropane (C3F8) gas injection.
The complexity, high morbidity, and cost associated with mechanical vitrectomy
make a less invasive and more affordable alternative treatment highly
desirable. The pneumatically assisted posterior vitreous detachment is
a simple outpatient procedure with minimal surgical manipulation, and
low morbidity may have an important clinical role.
Optical coherence tomography documentation supports the use of an intravitreous
gas injection, a relatively safe and low-cost procedure, to assist a posterior
vitreous detachment, with relief of traction.
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