glaucoma

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Related to pigmentary glaucoma: Pigment dispersion syndrome

glaucoma

(glôkō`mə), ocular disorder characterized by pressure within the eyeball caused by an excessive amount of aqueous humor (the fluid substance filling the eyeball). This causes pressure against the optic nerve and compression of the blood vessels of the eye—the resulting impairment of vision ranges from slight abnormalities to total blindness. Chronic open-angle glaucoma is the result of impeded drainage of aqueous humor. In acute angle-closure glaucoma, the anterior chamber of the eye is shallower and the iris may obstruct the meshwork at the entrance of the canal of Schlemm. Although glaucoma is a leading cause of blindness in the United States, with timely treatment blindness is almost always avoided.

Chronic glaucoma begins gradually over a period of months or years, usually in patients over the age of 40. There are no symptoms in the early stages, and the condition can be detected only by measurement of the intraocular pressure. Such an examination is recommended every three years for all persons over the age of 20. As the disease progresses, often the only symptom is a gradual loss of peripheral vision. Chronic glaucoma can usually be controlled with eye drops or pills that increase the outflow or decrease the production of aqueous humor; laser treatment is also effective in the early stages. If treatment is continued throughout life, useful vision will be preserved in most cases; untreated individuals will gradually become blind.

Acute closed-angle glaucoma, which accounts for only 10% of the incidence of the disease, begins abruptly with severe pain and blurred vision. It is a medical emergency that causes permanent blindness in two to five days if left untreated. Surgery is usually necessary.

Glaucoma

 

(also called “yellow water” or “green water” in Russian—in glaucoma the region of the pupil sometimes begins to gleam with a yellowish gray or bluish gray light), a disease of the eyes, the principal symptom of which is an increase in intraocular pressure with a reduction of vision.

Intraocular pressure in glaucoma sometimes reaches 80 mm of mercury, or 10.67 kilonewtons (kN)/m2. (Normal pressure is 18-27 mm of mercury, or 2.4-3.6 kN/m2.) The pressure in the eye may rise spontaneously (primary glaucoma) or as the result of a previous or current disease of the eye (secondary glaucoma). The underlying cause of the disease is a disruption of the circulation of intraocular fluid—most commonly, difficulty in its drainage. Glaucoma usually develops in the elderly, often affecting both eyes, and as a rule proceeds chronically; in the absence of systematic treatment it is progressive. Glaucomas may be defined as either congestive (narrow angle), characterized by periodic clouding of vision, rainbowed halos around a light source, and a sensation of pressure in and around the eye, simple (open angle), in which these subjective phenomena are absent. In any form of glaucoma visual acuity gradually diminishes, the field of vision becomes limited, and the optic nerve atrophies. An acute attack of glaucoma, characterized by an abrupt rise in intraocular pressure, may develop at any stage of the disease; severe pains in and around the eye develop, there is reddening of the eyes, edema and clouding of the cornea, dilatation of the pupil, and reduction of vision, sometimes to the point of blindness. There is often accompanying nausea and vomiting. Glaucoma is the most common cause of blindness. The treatment may be medical or sometimes surgical. In the USSR prevention consists of examination of persons over 40 years of age and treatment of patients with established glaucoma at out-patient prevention and treatment clinics. Prevention of blindness from glaucoma involves early diagnosis of the disease and systematic treatment.

REFERENCES

Averbakh, M. I. “Glaukoma.” In Oftalmologicheskie ocherki. Moscow, 1949.
Mnogotomnoe rukovodstvo po glaznym bolezniam, vol. 2. [Edited by V. N. Arkhangel’skii.] Moscow, 1960.

M. L. KRASNOV

glaucoma

[glau̇′kō·mə]
(medicine)
A disease of the eye characterized by increased fluid pressure within the eyeball.

glaucoma

a disease of the eye in which pressure within the eyeball damages the optic disc, impairing vision, sometimes progressing to blindness
References in periodicals archive ?
The influence of peripheral iridotomy on the intraocular pressure course in patients with pigmentary glaucoma.
A 12 month, randomized, double-masked study comparing latanoprost with timolol in pigmentary glaucoma.
Coronado Industries, has for the past seven years, been dedicated to the development and commercialization of its patented glaucoma treatment device which treats open angle and pigmentary glaucoma.
For example, exercise in pigmentary glaucoma is known to produce an IOP spike and if your patient is a regular at the gym or runs/ goes jogging, it is worth asking them to exercise immediately prior to evaluation.
Coronado Industries has for the past seven years been dedicated to the development and commercialization of its patented Glaucoma Treatment Device which treats open angle and pigmentary glaucoma.
Coronado Industries' PNT treatment is designed to treat the two most common types of glaucoma - open-angle and pigmentary glaucoma.
Applicable to open-angle and pigmentary glaucoma, the two most common types of glaucoma, PNT(TM) uses a suction device that is applied to the eye for one to two minuets.
At Arizona Glaucoma Institute, owned by Coronado's wholly owned subsidiary American Glaucoma, evaluation of approximately two years of data from a recently concluded study of 190 patients receiving pneumatic trabeculoplasty has shown that the procedure, originally designed to treat Primary Open Angle Glaucoma (POAG), pigmentary glaucoma and glaucoma associated with pseudoexfoliation of the lens capsule, is of value in treating "ocular hypertension" as well.