INTRODUCTION: The presence of aqueous humor in the anterior cavity of the eye creates a pressure called intraocular pressure. An increase in this pressure is an important risk factor for glaucoma, which is now defined as a group of disorders that damage the optic nerve and cause loss of vision. Other risk factors include high blood pressure and diabetes.
PATHOPHYSIOLOGY: In the most common form of glaucoma, aqueous humor is not reabsorbed properly into the canal of Schlemm. Increased pressure in the anterior cavity is transmitted to the lens, the vitreous humor, and the retina and optic nerve. As pressure on the retina increases, halos may be seen around bright lights, and peripheral vision is lost. Frequently, however, there are no symptoms.
SIGNS AND SYMPTOMS: A person with glaucoma may not notice the shrinking visual field in one eye before vision loss is far advanced. This happens because the brain will suppress a faulty image from one eye that it cannot easily integrate with the normal image of the other eye. When both eyes are affected, the person may not become aware of the gradual loss of peripheral vision, because close work such as reading does not require the edges of the visual fields.
PREVENTION AND TREATMENT: Glaucoma may often be controlled with medications that constrict the pupil and flatten the iris, thus opening up access to the canal of Schlemm. If these or other medications are not effective, laser surgery may be used to create a larger drainage canal. Anyone over the age of 40 should have a test for glaucoma; anyone with a family history of glaucoma should have this test annually, as should those with diabetes or high blood pressure. If diagnosed early, glaucoma is treatable, and blindness can usually be prevented.
RELATED;
1. BLOOD PRESSURE AND HYPERTENSION
4. REFERENCES
No comments:
Post a Comment