Essential of diagnosis.
No symptoms in the early stage.
Insidious progressive bilateral loss of peripheral vision resulting in tunnel vision but preserved.
Visual acuities until advanced disease.
Pathologic cupping of the optic disks.
Intraocular pressure is usually elevated.
General considerations.
Glaucoma is characterized by gradually progressive excavation (cupping) and corresponding pallor of the optic disk with optic loss of vision progressing from slight visual field loss to complete blindness. In chronic open secondary the intraocular glaucoma, primary or secondary, the intraocular pressure is elevated due to reduced drainage of aqueous fluid through tubular meshwork. In chronic angle closure glaucoma which is particularly common in Inuits and eastern asians, flow of aqueous fluid into the anterior chamber angle is obstructed. In normal-tension glaucoma intraocular pressure is not elevated but the same pattern of the output nerve damage occurs probably due to vascular insufficiency.
Primary open-angle glaucoma is usually bilateral. There is an increased prevalence in first degree relatives of affected individuals and diabetic patients. In Afro Caribbeans and African and probably in Hispanics it more frequently occurs at early age, resulting in more severe optic nerve damage. Secondary open-angle glaucoma may result from ocular disease e.g. pigment dispersion, Pseudoexfoliation, uveitis or trauma or corticosteroid therapy, whether it is intra ocular, topical, systemic, inhaled of administered by nasal spray. Worldwide about 45 million people have open angle glaucoma, of whom about 4.5 million are bilaterally blind. About a million people of whom approximately 50% live in China are bilaterally blind from chronic angle closure glaucoma.