Br J Ophthalmol 1998;82:880-883 ( August )
Effects of short term increase of intraocular pressure on optic
disc cupping
Augusto Azuara-Blanco,a b
Alon Harris,b c
Louis B Cantor,b
Marcio M Abreu,c
Monika Weinlandc
a Department of
Ophthalmology, Nottingham University Medical School, Nottingham, b Department of
Ophthalmology, Indiana University School of Medicine, Indianapolis,
Indiana, USA, c Department of Physiology and Biophysics,
Indiana University School of Medicine, Indianapolis, Indiana, USA
Correspondence to: Alon Harris, PhD, Department of
Ophthalmology, 702 Rotary Circle, Indianapolis, IN 46202-5175, USA.
Accepted for publication 26 February 1998
AIMS
To evaluate the
effect of acute elevation of intraocular pressure (IOP) on optic disc cupping.
METHODS10 emmetropic
and 10 myopic volunteers were included in this study. The cup area (CA)
and cup volume (CV) of the optic disc were determined with the
Heidelberg retina tomograph (HRT). After baseline determinations, a
suction cup was used to increase the intraocular pressure (IOP) to
20-25 mm Hg above the baseline and HRT images were obtained.
RESULTSBaseline IOP
was 13.5 (SD 1.3) mm Hg and 12.6 (2.6) mm Hg in the emmetropic and
myopic groups, respectively. The IOP was elevated to 35.4 (3.3) mm Hg
and 34.4 (2.5) mm Hg in the emmetropic and myopic groups, respectively.
When compared with their baseline values, the cupping variables (CA and
CV) were significantly increased (p<0.05) during the suction treatment
in both emmetropic and myopic subjects.
CONCLUSIONThere was a
significant enlargement in the optic disc cupping during the artificial
increment of intraocular pressure in both emmetropic and myopic eyes.
In non-glaucomatous eyes the optic nerve head has a partially dynamic
topography dependent upon the level of IOP.
Keywords:
optic disc;
intraocular
pressure;
compliance;
glaucoma
© 1998 by British Journal of Ophthalmology
