Scleral buckling and ocular rigidity. Clinical ramifications
T. R. Friberg and S. B. Fourman
Department of Ophthalmology, Eye and Ear Institute, University of Pittsburgh, PA 15213.
Ocular rigidity is the change in intraocular pressure produced by an
incremental change in intraocular volume. Ocular rigidity was determined in
14 donor eyes by injecting small increments of a balanced salt solution
through the limbus, while continually monitoring the intraocular pressure
with a transducer. A buckling procedure was then performed in these eyes
with the use of various solid silicone or stainless steel encircling
elements, and the experiments were repeated. Buckled eyes were
significantly less rigid than unbuckled eyes, and eyes with higher buckles
were significantly less rigid than those with shallower buckles. The
observed changes in rigidity are likely secondary to changes in the shape
and stress distribution of the scleral shell and are only to a small degree
related to the elasticity of the encircling element. Greater volumes of
vitreous substitutes, gases, or antibiotics may be injected into buckled
eyes compared with unbuckled eyes before excessive intraocular pressures
are reached.
