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.

Primary%20open-angle%20glaucoma Signs and Symptoms

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
Editor's Recommendations
Most Read Articles
Pearl Toh, 22 Oct 2020
The combination therapy comprising carfilzomib, cyclophosphamide and dexamethasone (KCd) is effective, with a tolerable safety profile, in an Asian cohort with high-risk multiple myeloma (MM) — thus providing a more economical alternative as a potential upfront regimen in resource-limited settings, according to leading experts during a myeloma education webinar.
Roshini Claire Anthony, 13 Nov 2020

Diabetes is a key risk factor for heart failure (HF), which is the leading cause of hospitalization in patients with or without diabetes. SGLT-2* inhibitors (SGLT-2is) have been shown to reduce the risk of hospitalization for HF (HHF) regardless of the presence or absence of diabetes.

Pearl Toh, 6 days ago
Inhaled corticosteroid (ICS) should be the mainstay of long-term asthma management — such is the key message of the latest Singapore ACE* Clinical Guidance (ACG) for asthma, released in October 2020.
Elvira Manzano, 17 Nov 2020
Invasive fungal infections, particularly those caused by Candida species, are common in hospitalized, immunocompromised, or critically ill patients and are associated with considerable morbidity and mortality.