primary%20open-angle%20glaucoma
PRIMARY OPEN-ANGLE GLAUCOMA
Primary open-angle glaucoma (POAG) is a chronic, progressive, usually bilateral disease of the eye with an insidious onset.
It is most often characterized by optic nerve damage, defects in the retinal fiber layer and subsequent visual field loss in the absence of underlying ocular disease or congenital abnormalities.
It is generally asymptomatic until it has caused a significant loss of visual field.
Occasionally, patients with very high intraocular pressure may complain of nonspecific headache, discomfort, intermittent blurring of vision or even halos caused by corneal edema.

Introduction

Ocular Hypertension (OH)

  • Refers to intaocular pressure (IOP) >21 mmHg or IOP that is >2-3 standard deviations from the normal population mean, in the absence of optic nerve damage or visual field defects
  • Represents a major risk for future development of primary open-angle glaucoma (POAG)

Definition

  • Primary open-angle glaucoma (POAG) is a chronic, progressive, usually bilateral disease with an insidious onset
  • Most often characterized by optic nerve damage, defects in the retinal fiber layer and subsequent visual field loss in the absence of underlying ocular disease or congenital abnormalities
    • Usually of adult onset with open normal appearance of anterior chamber angles

Signs and Symptoms

  • It is generally asymptomatic until it has caused a significant loss of visual field
    • Visual acuity is lost when there is central visual field loss which is a late manifestation of the disease
  • Occasionally, patients with very high intraocular pressure (IOP) may complain of nonspecific headache, discomfort, intermittent blurring of vision or even halos caused by corneal edema
    • Although a high IOP is associated with open-angle glaucoma, it is not necessary for the diagnosis and is considered a “risk factor”; many patients with primary open-angle glaucoma (POAG) do not have increased IOP and not all patients with increased IOP will develop a glaucoma

Risk Factors

  • Age - incidence of primary open-angle glaucoma (POAG) increases with age
  • Race - estimated prevalence is approximately 3 times greater among African Americans, Hispanics/Latino and even higher among Afro-Caribbeans
  • Family history - risk is increased in those with an affected first-degree relative (parent or sibling, with the latter having the strongest association)
  • Elevated intraocular pressure (IOP)
    • Currently, there is no evidence of a threshold IOP for the onset of POAG although risk of developing glaucoma is 12 times greater for those with IOP >26 mmHg
    • Traditional definition of a normal IOP is 2 standard deviations above normality (21 mmHg)
  • Thin central cornea increases risk for developing glaucoma
  • Pseudoexfoliation
  • Myopia
  • Low ocular perfusion pressures
  • Local/ocular
    • Optic disc hemorrhage
    • Peripapillary atrophy
    • Larger cup-to-disc ratio
  • Systemic
    • Cardiovascular disease
    • Hypertension
    • Type 2 diabetes mellitus
    • Hypothyroidism
    • Migraine headache, peripheral vasospasm
    • Obstructive sleep apnea
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