The only signs are gradually progressive visual field loss and optic nerve changes (increased cup-to-disc ratio on fundoscopic examination). About 10% of people with closed angles present with acute angle closure characterized by sudden ocular pain, seeing halos around lights, red eye, very high intraocular pressure (>30 mmHg (4.0 kPa)), nausea and vomiting, suddenly decreased vision, and a fixed, mid-dilated pupil. It is also associated with an oval pupil in some cases. Acute angle closure is an emergency. Opaque specks may occur in the lens in glaucoma, known as glaukomflecken. Causes
Ocular hypertension (increased pressure within the eye) is the most important risk factor for glaucoma, but only about 50% of people with primary open-angle glaucoma actually have elevated ocular pressure. Ocular hypertension—an intraocular pressure above the traditional threshold of 21 mmHg (2.8 kPa) or even above 24 mmHg (3.2 kPa)—is not necessarily a pathological condition, but it increases the risk of developing glaucoma. One study found a conversion rate of 18% within five years, meaning fewer than one in five people with elevated intraocular pressure will develop glaucomatous visual field loss over that period of time. It is a matter of debate whether every person with an elevated intraocular pressure should receive glaucoma therapy; currently, most ophthalmologists favor treatment of those with additional risk factors.Open-angle glaucoma accounts for 90% of glaucoma cases in the United States. Closed-angle glaucoma accounts for fewer than 10% of glaucoma cases in the United States, but as many as half of glaucoma cases in other nations (particularly East Asian countries).
Nonpenetrating deep sclerectomy (NPDS) surgery is a similar, but modified, procedure, in which instead of puncturing the scleral bed and trabecular meshwork under a scleral flap, a second deep scleral flap is created, excised, with further procedures of deroofing the Schlemms canal, upon which, percolation of liquid from the inner eye is achieved and thus alleviating intraocular pressure, without penetrating the eye. NPDS is demonstrated to have significantly fewer side effects than trabeculectomy. However, NPDS is performed manually and requires higher level of skills that may be assisted with instruments. In order to prevent wound adhesion after deep scleral excision and to maintain good filtering results, NPDS as with other non-penetrating procedures is sometimes performed with a variety of biocompatible spacers or devices, such as the Aquaflow collagen wick, ologen Collagen Matrix, or Xenoplast glaucoma implant.Laser-assisted NPDS is performed with the use of a CO2 laser system. The laser-based system is self-terminating once the required scleral thickness and adequate drainage of the intraocular fluid have been achieved. This self-regulation effect is achieved as the CO2 laser essentially stops ablating as soon as it comes in contact with the intraocular percolated liquid, which occurs as soon as the laser reaches the optimal residual intact layer thickness. Lens extraction
For people with chronic closed-angle glaucoma, lens extraction can relieve the block created by the pupil and help regulate the intraocular pressure. Prognosis
In open-angle glaucoma, the typical progression from normal vision to complete blindness takes about 25 years to 70 years without treatment, depending on the method of estimation used.