Ophthalmology Book



Aka: Lacrimation
  1. Physiology
    1. Layers of tears
      1. Inner: Mucin produced by goblet cells of Conjunctiva
      2. Mid: Aqueous layer by lacrimal glands (90% of tears)
        1. Water (largest component)
        2. Glucose
        3. Lysozyme
        4. Lactoferrin
        5. Secretory Immunoglobulin (IgA)
      3. Outer: Lipids produced by meibomian glands
        1. Prevents evaporation
    2. Function of tears
      1. Maintains smooth eye surface for visual clarity
      2. Lubricates eye surface to facilitate blinking
      3. Barrier to infection
    3. Function of Blinking
      1. Normally, blinking occurs every 5 seconds
      2. Spreads tear film and directs toward lacrimal duct
  2. Causes: Increased Tear Secretion
    1. Emotion
    2. Foreign body irritation
    3. Corneal Ulcer
    4. Conjunctivitis
    5. Coryza
    6. Measles
    7. Hay fever
    8. Cluster Headache (unilateral tearing)
    9. Toxin
      1. Chronic Iodine toxicity (Iodism)
      2. Chronic bromide toxicity (Bromism)
      3. Arsenic
  3. Causes: Absent or decreased Tear Secretion
    1. See Dry Eyes
    2. See Schirmer's Test
  4. Causes: Obstruction of the Lacrimal Ducts
    1. Dacryocystitis
    2. Lacrimal calculus
    3. Congenital obstruction
    4. Cicatrix
    5. Eyelid Edema
  5. References
    1. Rheinstrom in Yanoff (1999) Ophthalmology, Mosby, 14.1

Lacrimation (C0423153)

Definition (NCI) Tearing; excessive shedding of tears.
Concepts Finding (T033)
SnomedCT 139559008, 162289008, 64702000
Dutch traanproductie
French Larmoiement
German Traenensekretion
Italian Lacrimazione
Portuguese Secreção lacrimal
Japanese 流涙, リュウルイ
English Tearing, lacrimation, lacrimation (physical finding), tear production, tearing, Lacrimation
Spanish Lagrimeo
Czech Tvorba slz
Hungarian Könnyezés
Derived from the NIH UMLS (Unified Medical Language System)

You are currently viewing the original 'fpnotebook.com\legacy' version of this website. Internet Explorer 8.0 and older will automatically be redirected to this legacy version.

If you are using a modern web browser, you may instead navigate to the newer desktop version of fpnotebook. Another, mobile version is also available which should function on both newer and older web browsers.

Please Contact Me as you run across problems with any of these versions on the website.

Navigation Tree