Open-angle glaucoma stems from a reduced outflow of aqueous humor and is amongst the most important causes of blindness. Symptoms such as peripheral vision loss may not be apparent until severe optic nerve damage occurs. The diagnosis is made by a thorough physical exam and use of various ophthalmological procedures.
Glaucoma is one of the leading causes of blindness in the general population, and open-angle glaucoma is the most common form   . Numerous risk factors for this disorder have been identified, including older age, genetic factors (a seven-fold increased risk is confirmed in the setting of a positive family history), trauma, use of corticosteroids (either topical or systemic), black race, and high intraocular pressure, which is considered to be the main event in the pathogenesis   . Unfortunately, one of the most prominent clinical features of glaucoma is that its symptoms appear only when substantial damage to the optic nerve and disk occurs  . In fact, open-angle glaucoma is usually diagnosed incidentally, when examination of the eye is performed due to other causes . Studies have shown that loss of more than 40% of optic nerve fibers is necessary to produce symptoms , and patients report a gradual loss of peripheral vision that is often perceived as tunnel vision  . In most patients, open- angle glaucoma appears bilaterally, and inability to perform daily activities, such as driving and newspaper reading is often a consequence of the reduced visual field, while some patients report missing stairs as well . Glaucoma invariably causes irreversible blindness in the absence of a timely diagnosis and an early appearance of vision-related symptoms must be taken seriously for that reason.
The diagnostic workup of patients reporting vision impairment must start with a thorough patient history that can reveal the presence of risk factors and assess the course and progression of symptoms. A positive family history, previous eye-related disorders and potential use of corticosteroids must be noted. A physical examination including visual field examination should be performed. As symptoms may be absent in the early stages, direct ophthalmoscopy is also recommended as a mandatory part of primary practice   . A more detailed ophthalmoscopic examination, however, is required to confirm glaucoma and various non-invasive procedures and these may be   :