Techniques and variables in visual field testing
A number of factors can affect a visual field test other than the disease being studied. It is important to minimize the influence of these variables as completely as possible…
Other psychophysical tests
INTRODUCTION Glaucoma diagnosis and monitoring require assessments of both structure and function of the optic nerve and ganglion cell layer. The traditional tests of these parameters for the past half…
Intraocular pressure
INSTRUMENTS FOR MEASURING INTRAOCULAR PRESSURE It is possible to measure intraocular pressure (IOP) directly in a living eye using a manometric technique. For this approach a needle is inserted into…
Methods of gonioscopy
DEFINITION Gonioscopy is biomicroscopic examination of the anterior chamber angle of the eye, where aqueous humor gains access to Schlemm’s canal. It enables the glaucomas to be classified into two…
Gonioscopic anatomy
GROSS ANATOMY ANATOMIC FEATURES OF NORMAL EYES The anatomic structures that regulate intraocular pressure (IOP) are contained in the anterior segment of the eye. Behind the rounded apex of the…
Visual field theory and methods
THE NORMAL VISUAL FIELD The normal visual field has been described as an island of vision in a sea of darkness. This island has a sharp central peak, corresponding to…
Aqueous humor outflow system overview
Aqueous humor circulation through the anterior segment of the eye represents one of the many cardiac circulatory loops that also include the various arteriovenous, lymphatic, and cerebrospinal fluid circulations. Each…
Aqueous humor formation
FUNCTION OF AQUEOUS HUMOR Aqueous humor was originally thought to be stagnant. It was not until 1921 that Seidel proved that the aqueous was, indeed, circulating. Using a needle, Seidel…
Introduction and classification of the glaucomas
DEFINITIONS The concepts and definitions of glaucoma have evolved in the past 100 years, and still they remain imprecise and subject to technical qualifications. The word glaucoma originally meant ‘clouded’…
