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

• Primary open-angle glaucoma (POAG) is a chronic, progressive, irreversible, 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

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 POAG

• 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 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 POAG do not have increased IOP and not all patients with increased IOP will develop a glaucoma

• Age - incidence of POAG increases with age
• Race - estimated prevalence is approximately 3 times greater among African Americans, Hispanics/Latino and even higher among Afro-Caribbeans
• Male sex
• Family history - risk is increased in those with an affected first-degree relative (parent or sibling, with the latter having the strongest association)
• Genetics - mutations in the myocilin (MYOC) gene
• Elevated 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 (DM)
  • Hypothyroidism
  • Migraine headache, peripheral vasospasm
  • Obstructive sleep apnea