Diagnosis
Î POAG is a chronic ocular disease process that is progressive,
generally bilateral, but often asymmetric.
Î POAG represents a spectrum of disease in adults in which the
susceptibility of the optic nerve to damage varies among patients.
Although many patients with POAG present with elevated IOP, nearly
40% of those with otherwise characteristic POAG may not have
elevated IOP measurements.
Î Population-based studies indicate that a variable proportion of
patients with IOP >21 mmHg have glaucomatous optic nerve damage
(See Figure 1). This suggests that an IOP level of >21 mmHg is an
arbitrarily defined level and highlights the poor predictive value of
utilizing a specific IOP cutoff as a measure for screening or diagnosis
of POAG.
Î The vast majority of patients with POAG have disc changes or disc and
visual field changes, but there are rare cases where there may be early
visual field changes before there are detectable changes to the optic
nerve.
0%
10%
20%
30%
40%
50%
60%
70%
80%
Figure 1. Variable Proportion of Patients with IOP >21 mmHg
Having Glaucomatous Optic Nerve Damage
2
Population-Based Studies
