- A disorder in which increased intraocular pressure leads to eventual vision impairment and possibly to degeneration of the optic nerve. It may be primary or occur secondary to other ocular disease. Glaucoma is classified as open or closed angle.

Causes and Incidence The etiology of primary glaucoma is unknown, but predisposing factors include heredity, hyperopia, and vasomotor instability. It is estimated that 1.5% to 2% of Americans over 40 years of age have glaucoma, and more than 12% of newly diagnosed cases of blindness are attributable to glaucoma. Blacks and those with a family history are most susceptible. Ninety percent of primary glaucoma cases are the open-angle type, which occurs most often after age 65.

Disease Process Increased intraocular pressure (IOP) is related to an imbalance in the production, inflow, and outflow of aqueous humor. Inflow occurs through the pupil and outflow through the meshwork at the juncture of the iris and cornea. In secondary glaucoma the meshwork becomes clogged by blood, fibrin, or inflammatory cells produced by an underlying ocular disorder. Primary open-angle glaucoma is marked by degenerative changes to the meshwork that block outflow. In primary closed-angle glaucoma, the anterior chamber is shallow, the filtration angle is narrow, and the iris obstructs the meshwork at Schlemm’s canal. Sometimes dilation of the pupil or trauma pushes the iris forward, narrowing the angle and resulting in obstruction in an acute attack. Primary or secondary glaucoma may be congenital; the condition is hereditary (primary) or is caused by fetal defects in the ocular structure or underlying congenital systemic disorders (secondary).

Symptoms

Open angle
Often asymptomatic; frequent changes in prescription for glasses; mild headaches, vague visual disturbances; halos around lights; difficulty adjusting to darkness

Closed angle
Severe pain in and around eye; tearing; colored rainbow halos around lights; recurring episodes of blurring and impaired vision; mild dilation of pupils; hazy cornea; possible nausea and vomiting

Potential Complications Untreated glaucoma leads to progressively diminishing vision, degeneration of the optic nerve, and blindness.

Diagnostic Tests

Tonometry
To measure elevation in IOP

Visual field studies
To detect impairment in central and peripheral visual fields

Gonioscopy
To detect cellular debris or adhesions and differentiate openangle from closed-angle type

Ophthalmoscopy
To visualize optic nerve

Treatments In secondary glaucoma, treatment focuses on the underlying disease process, in conjunction with mydriasis.

Surgery
Open angle: laser/external trabeculoplasty to improve drainage if medications fail; placement of filtering devices if trabeculoplasty fails.

Closed angle: laser iridotomy/peripheral iridectomy to push iris back and increase angle.

Ocular implants for some complex forms of glaucoma.

Drugs
Open angle: betaadrenergic blockers and diuretics to reduce production of aqueous humor, miotics to reduce pressure, and adrenergics to increase aqueous outflow.

Closed angle: hyperosmotic agents, carbonic anhydrase inhibitors, and miotics to reduce pressure or abort acute attack; narcotic analgesics for pain.

General
Open angle: avoidance of tobacco use, fatigue, emotional upset, and ingesting large quantities of fluid; instruction in instillation of eye drops, and long-term use of medications and their side effects.

Medi-Info.COM finds at this phrases

• calcium in lymph node neck
• causative agent of parasitic gastroenteritis
• pathophysiology hepatitis
• urine plasma osmolality diabetes insipidus
• pathophysiology of hepatitis
• bovine tb disease process
• Medical Information

Related Posts

No related posts.

Related posts brought to you by Yet Another Related Posts Plugin.

21 Comments »

1. [...] diagnostic tests glaucoma [...]

   Pingback by Stomach Cancer (Gastric Cancer) - Disease Process, Symptoms, Diagnostic Tests, Treatments at Medi-Info, Medical information for our connected world — March 15, 2010 @ 4:09 pm

2. [...] disease process of glaucoma [...]

   Pingback by Diarrhea - Disease Process, Symptoms, Diagnostic Tests, Treatments at Medi-Info, Medical information for our connected world — May 27, 2010 @ 3:25 pm

3. [...] disease process of glaucoma [...]

   Pingback by Mononucleosis - Disease Process, Symptoms, Diagnostic Tests, Treatments at Medi-Info, Medical information for our connected world — June 12, 2010 @ 6:54 am

4. [...] rainbow halos around lights [...]

   Pingback by Uterine Bleeding, Dysfunctional - Disease Process, Symptoms, Diagnostic Tests, Treatments at Medi-Info, Medical information for our connected world — June 16, 2010 @ 6:27 am

5. [...] process of glaucoma [...]

   Pingback by Zollinger-Ellison Syndrome - Disease Process, Symptoms, Diagnostic Tests, Treatments at Medi-Info, Medical information for our connected world — June 23, 2010 @ 10:34 pm

6. [...] rainbow halos around lights medicines [...]

   Pingback by Ulcerative Colitis - Disease Process, Symptoms, Diagnostic Tests, Treatments at Medi-Info, Medical information for our connected world — June 24, 2010 @ 1:50 pm

7. [...] rainbow around lights [...]

   Pingback by Pulmonary Embolism - Disease Process, Symptoms, Diagnostic Tests, Treatments at Medi-Info, Medical information for our connected world — June 27, 2010 @ 11:25 am

8. [...] seeing halos around lights BLURRED VISION [...]

   Pingback by Pancreatitis - Disease Process, Symptoms, Diagnostic Tests, Treatments at Medi-Info, Medical information for our connected world — June 28, 2010 @ 1:06 pm

9. [...] seeing halos around lights in one eyes [...]

   Pingback by Tetanus (Lockjaw) - Disease Process, Symptoms, Diagnostic Tests, Treatments at Medi-Info, Medical information for our connected world — July 3, 2010 @ 10:16 pm

10. [...] rainbows around lights [...]

    Pingback by Influenza (Flu) - Disease Process, Symptoms, Diagnostic Tests, Treatments at Medi-Info, Medical information for our connected world — July 8, 2010 @ 5:02 pm

11. [...] why am i seeing a rainbow around lights? [...]

    Pingback by Hernia (External) - Disease Process, Symptoms, Diagnostic Tests, Treatments at Medi-Info, Medical information for our connected world — July 9, 2010 @ 6:09 am

12. [...] glaucomadisease [...]

    Pingback by Gastritis - Disease Process, Symptoms, Diagnostic Tests, Treatments at Medi-Info, Medical information for our connected world — July 10, 2010 @ 9:24 am

13. [...] coloured halos etiology [...]

    Pingback by Spinal Cord Injury (Paraplegia, Quadriplegia) - Disease Process, Symptoms, Diagnostic Tests, Treatments at Medi-Info, Medical information for our connected world — July 13, 2010 @ 6:43 pm

14. [...] disease process of glaucoma [...]

    Pingback by Myasthenia Gravis - Disease Process, Symptoms, Diagnostic Tests, Treatments at Medi-Info, Medical information for our connected world — July 16, 2010 @ 9:43 am

15. [...] halos around lights glaucoma [...]

    Pingback by Hiatal Hernia - Disease Process, Symptoms, Diagnostic Tests, Treatments at Medi-Info, Medical information for our connected world — July 26, 2010 @ 12:04 pm

16. [...] process of glucoma [...]

    Pingback by Endocarditis - Disease Process, Symptoms, Diagnostic Tests, Treatments at Medi-Info, Medical information for our connected world — July 27, 2010 @ 4:43 pm

17. [...] glaucoma disease process [...]

    Pingback by Epistaxis - Disease Process, Symptoms, Diagnostic Tests, Treatments at Medi-Info, Medical information for our connected world — August 3, 2010 @ 9:49 pm

18. [...] glaucoma- diagnostic tests [...]

    Pingback by Crohn’s Disease (Regional Enteritis) - Disease Process, Symptoms, Diagnostic Tests, Treatments at Medi-Info, Medical information for our connected world — August 4, 2010 @ 1:15 pm

19. [...] Halos around light in glaucoma [...]

    Pingback by Thyroid Cancer - Disease Process, Symptoms, Diagnostic Tests, Treatments at Medi-Info, Medical information for our connected world — August 5, 2010 @ 3:23 am

20. [...] ocular condition causing coloured halos [...]

    Pingback by Coronary Artery Disease (See also Angina and Myocardial Infarction) - Disease Process, Symptoms, Diagnostic Tests, Treatments at Medi-Info, Medical information for our connected world — August 22, 2010 @ 6:45 pm

21. [...] information glaucoma [...]

    Pingback by Rheumatic Fever - Disease Process, Symptoms, Diagnostic Tests, Treatments at Medi-Info, Medical information for our connected world — August 30, 2010 @ 7:29 am

RSS feed for comments on this post. TrackBack URL

Leave a comment

You must be logged in to post a comment.