Ophthalmology Book

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Glaucoma

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  1. See Also
    1. Open Angle Glaucoma
    2. Narrow Angle Glaucoma
  2. Definition
    1. Increased Intraocular Pressure with Optic Nerve injury
  3. Epidemiology
    1. Within top 3 causes of blindness in U.S.
      1. Leading cause of blindness in non-white
    2. Prevalence: 2 Million in United States
      1. Only 50% are estimated to now be under treatment
      2. 120,000 are blind due to glaucoma
  4. Pathophysiology
    1. Elevated Intraocular Pressure (IOP)
      1. Increased production of Aqueous Humor by ciliary body
      2. Increased outflow resistance at Aqueous Outflow Angle
        1. Trabecular meshwork
        2. Canal of Schlemm
    2. Progressive changes in optic disc
      1. Nerve damage related to increased IOP is variable
        1. Glaucoma suspects (66% of those with high IOP)
          1. No damage despite high Intraocular Pressure (>21)
          2. Optic Nerve injury rate in suspects: 1% per year
        2. Normal-pressure Glaucoma (15% of Glaucoma patients)
          1. Normal Intraocular Pressure (21 mmHg or less)
          2. Glaucoma-related Optic Nerve damage
      2. Progressive glaucomatous cupping at the optic disc
        1. IOP collapses Optic Nerve head structural support
        2. Axons destroyed by mechanical compression
    3. Peripheral visual field loss
      1. Open Angle Glaucoma: Slowly progressive
      2. Narrow Angle Glaucoma: Rapid Vision Loss
  5. Types
    1. Primary Glaucoma
      1. Open Angle Glaucoma (89%)
        1. Outflow blocked by microscopic outflow changes
        2. Results in progressive peripheral Vision Loss
        3. Usually asymptomatic until 40% of nerve loss
      2. Narrow Angle Glaucoma
        1. Outflow tract blocked by base of iris
        2. Permanent Vision Loss may occur in hours
        3. Presents as acute painful red eye with Vomiting
    2. Secondary Glaucoma
      1. Medications that increase IOP in those predisposed
        1. Corticosteroids (Systemic and Topical)
          1. Reversible
        2. Mild Adrenergic or Anticholinergic Medications
          1. Examples
            1. Cold Medications
            2. Antidepressants
            3. Antidiarrheals
          2. Effect: Dilate Pupil
            1. Theoretically worsen angle closure glaucoma
            2. Not contraindicated in Glaucoma
  6. Resources
    1. Aging Eye Glaucomatrac (Glaucoma Management Tracking)
      1. http://www.agingeye.net/glaucomacharting.index
    2. Aging Eye Glaucoma Video
      1. http://www.agingeye.net/mainnews/video.php
    3. Glaucoma Foundation
      1. http://www.glaucoma-foundation.org
      2. Phone: 1-800-Glaucoma
  7. References
    1. Alward (1998) N Engl J Med 339:1298
    2. Distelhorst (2003) Am Fam Physician 67(9):1937
    3. Infeld (1998) Postgrad Med 74:709

Glaucoma (C0017601)

Definition (MSH)An ocular disease, occurring in many forms, having as its primary characteristics an unstable or a sustained increase in the intraocular pressure which the eye cannot withstand without damage to its structure or impairment of its function. The consequences of the increased pressure may be manifested in a variety of symptoms, depending upon type and severity, such as excavation of the optic disk, hardness of the eyeball, corneal anesthesia, reduced visual acuity, seeing of colored halos around lights, disturbed dark adaptation, visual field defects, and headaches. (Dictionary of Visual Science, 4th ed)
Definition (CSP)group of diseases characterized by increased intraocular pressure resulting in damage to the optic nerve and retinal nerve fibers.
Definition (NCI)Increased pressure in the eyeball due to obstruction of the outflow of aqueous humor.
ConceptsDisease or Syndrome (T047)
ICD9365, 365.9
MSHD005901
BasqueGLAUKOMA
DanishGlaukom
DutchGlaucoom
EnglishGlaucoma, Glaucomas, Unspecified glaucoma
FinnishVIHERKAIHI
FrenchGlaucome
GermanGlaukom
Hebrewglaukoma
Hungarianzoldhalyog
ItalianGlaucoma
NorwegianGRONN STAER/GLAUKOM
PortugueseGlaucoma
SpanishGlaucoma
SwedishGLAUKOM
Parent ConceptsEye diseases (C0015397), Intraocular pressure disorder (C0595921), Glaucoma (C0017601), Disorder of eye and adnexa NOS (C1314803), Eye (C0015392), Diagnosis/Diseases Component (C0497531), Ocular Hypertension (C0028840), Non-Neoplastic Eye Disorder (C1335009), Retinal Degeneration (C0035304), Degenerative Diseases, Central Nervous System (C0270715), Optic Disk Disorders (C0751402), Duplicate concept (C1274013)
SourcesAOD, CCS, COSTAR, CSP, CST, DXP, ICD9CM, ICPC, ICPCBAQ, ICPCDAN, ICPCDUT, ICPCFIN, ICPCFRE, ICPCGER, ICPCHEB, ICPCHUN, ICPCITA, ICPCNOR, ICPCPOR, ICPCSPA, ICPCSWE, LCH, LNC, MEDLINEPLUS, MSH, MTH, NCI, NDFRT, OMIM, SCTSPA, SNOMEDCT
Derived from the NIH UMLS (Unified Medical Language System)



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