LACRIMAL .SYSTEM.by.ayman essam.2012_mansdoc

					The lacrimal system consists
of:
 1. Secretory part (lacrimal secretory system)

 2. Excretory part (lacrimal drainage system)
Anatomy of the lacrimal drainage system
The lacrimal drainage system is
formed of:

 a. Two puncti:

        Located at the posterior edge of the lid margin,
  not seen except when the lid is everted. Each
  punctum lies    6 mm from the medial canthus on a
  slightly elevated portion called the papilla.
b. Two canaliculi:

    Vertical part: 2 mm
    Horizontal part: 8 mm
c. Lacrimal sac:

 The lacrimal sac is formed of:

  Body: This forms the main part.
  Fundus: blind upper portion which lies
   above the medial palpebral ligament.
  Neck: the neck is narrow and continuous
   with the nasolacrimal duct.
     Horner's muscle: is a part of the
orbicularis which is inserted into the
lacrimal fascia which surrounds the sac.
d. Nasolacrimal duct

 12-24 mm long

 Hasner valve in the inf. meatus
Precorneal tear film :

It's formed of 3 layers:

 a. Outer lipid layer: secreted by meibomian glands.

   Function:

      Prevent rapid evaporation of tears.
      Lubricates the eyelids over the globe.
b. Middle aqueous layer: secreted by the
   lacrimal gland.

  Function:

     Supplies oxygen to the corneal epithelium.
     Antibacterial as it contains lysozymes.
c. Inner mucinous layer: secreted by the goblet
  cells.


 Function:

      Makes the corneal epithelium hydrophilic.
  Congenital naso-lacrimal duct
               obstruction

Clinical picture:

 Epiphora, usually noticed at 2-3 weeks after
  birth.
 Recurrent conjunctivitis
 Pressure over the lacrimal sac  reflux of clear
   fluid, mucus, muco-pus or sometimes frank pus.
Sticky eye due to delayed canalization
       of the nasolacrimal duct .
Treatment of congenital dacryocystitis:
  1. Conservative: antibiotics      with   hydrostatic
     massage of the lacrimal sac,
  2. Probing is successful if done carefully as the
     lacrimal passages are still elastic.
3. Repeated syringing & irrigation with saline may
   cure the condition.
4. Silicone intubation of the lacrimal drainage system
   may be beneficial
5. Dacryocystorhinostomy (DCR).
        Acute dacryocystitis
Etiology:
  Predisposing    factor:   nasolacrimal   duct
   obstruction.
  Causative agent: Pneumococci, Staphylococci
   and Streptococci.

 Symptoms:
      Severe pain.
      Fever.
Signs:

1. Marked edema and redness of skin over the sac.
2. Regurgitation test: -ve due to congestion of the
  epithelium of canaliculi.
3. Tender swelling of lacrimal sac.
4. Abscess formation with fluctuation.
Complications:

  1. Lacrimal fistula: the sac may burst
     anteriorly through the skin.
  2. Pyocele: canaliculi may become obstructed.
  3. Orbital cellulitis and cavernous sinus
     thrombosis.
  4. Chronic dacryocystitis.
Treatment:

1. During the acute phase:

     A. Antibiotics: systemic and topical.
     B. Hot fomentations.
     C. Lotions: to clean the pus.
     D. Incision and drainage if an abscess forms.


2. After the acute attack subsides:
Dacryocystorhinostomy with fistulectomy if needed.
        Chronic dacryocystitis
Definition:
         A chronic inflammation of lacrimal sac
  secondary to obstruction of the naso-lacrimal duct. It
  is the commonest lacrimal sac disorder.
Etiology:
  Predisposing factor: Nasolacrimal duct obstruction.
  Causative agent:
   i. Pneumococci in 80%
   ii. Staphylococci, Streptococcus, trachoma, and fungi
   iii. TB and Syphilis: rare
Symptoms:

 1. Watery eye.
 2. Discharge.

Signs:
   Swelling of lacrimal sac below the medial
    palpebral ligament
   Regurgitation test +ve: Pressure on the
    swelling causes regurge of mucous or pus.
Expression of mucopurulent material in a
   patient with chronic dacryocystitis.
Complications:
 1. Chronic conjunctivitis.
 2. Epiphora, eczema and ectropion (vicious circle).
 3. Hypopyon ulcer.
 4. Endophthalmitis following intraocular operation.
 5. Mucocele and pyocele: if the canaliculi are
    obstructed.
 6. Lacrimal fistula.
Mucocele in a patient with
  chronic dacryocystitis
Treatment:
 1. Treatment of the cause of obstruction: e.g.
   relieve congestion, removal of a nasal
   polyp.
 2. Dacryocystorhinostomy:     operation    of
   choice.
Indications of DCR
   A.   Chronic dacryocystitis.
   B.   Mucocele of the lacrimal sac.
   C.   Lacrimal fistula (DCR and fistulectomy)
Contraindication of DCR
        A.Bad lacrimal sac: extensive adhesions and
         neglected cases.
        B.Bad nasal mucosa: atrophic rhinitis and
         polypi.
        C.T.B and tumors of the sac.
        D.Hypopyon ulcer.
Dacryocystectomy:


   Idea: removal of the lacrimal sac.
   Indications: indicated in cases where
    DCR can't be done.
                 Canaliculitis
Characterized clinically by:
   Persistent epiphora.
   Chronic conjunctivitis.
   Patulous lacrimal punctum.
   On pressure, a mucopurulent discharge which
    sometimes contains concretions, is seen extruded
    from the dilated punctum.


    Oedema of the left
     canaliculus due to
    chronic canaliculitis
 Pouting of the punctum in the
patient with chronic canaliculitis.
Treatment:
   Canaliculotomy is the curative method in these cases
   (slit the posterior wall of the canaliculus, all the
   fungoid masses are curetted and irrigate with saline).




       Two-snip procedure for punctal stenosis: (a) vertical
              cut; (b) horizontal cut; (C) final result .
                     DRY EYE
Etiology:
1. Inflammation of lacrimal gland e.g. sarcoidosis.
2. Congenital absence of the lacrimal gland.
3. Tumors of lacrimal gland: e.g. mixed lacrimal gland tumor.
4. Keratoconjunctivitis sicca: autoimmune disease leading to
   atrophy and fibrosis of the lacrimal gland, it occurs usually
   in females and may be associated with arthritis and dry
   mouth (Sjogren's syndrome).
5. Conjunctival scarring: due to trachoma, chemical burns,
   Stevens-Johnson syndrome and ocular cicatricial
   pemphigoid.
Clinical picture:
 Irritation and foreign body sensation.
 Deficient tear production measured by filter paper
  (Schirmer’s test). 5*35
      I : 5 min-N=10-25 -no anesthesia
          2 min-N=10-25 –anesthesia (basic)
      II : (reflex)- 2 min-15
 Rose Bengal staining of degenerated epithelium of
  conjunctiva, cornea and mucus. 1%
 Punctate epithelial erosion of the cornea. 2%
 Tear film break - up time (BUT) is diminished. 10 sec
                Tretment
1.Protective glasses.
2.Tear sub.
3. Punctal occlusion.
4. Corticosteroid (autoimmune dis.).
            WATERY EYE
1. Lacrimation
 Lacrimation is over secretion of tears

Etiology:
  Emotional conditions
  Reflex lacrimation from foreign body or
   inflammation of the lid margin, conjunctiva,
   cornea, iris and ciliay body, glaucoma, errors of
   refraction, and latent squint.
2. Epiphora:
       Epiphora is overflow of tears onto the cheek
due to inadequate drainage due to lacrimal pump
failure or obstruction of the lacrimal passages.

Etiology:
 A. LACRIMAL PUMP FAILURE:
  a. Lid margin: abnormality in posterior border
     of the lid margin.
  b. Ectropion.
  c. Orbicularis muscle: Facial palsy.
B. OBSTRUCTIVE EPIPHORA:

The obstruction may be:

  Congenital e.g. punctual atresia, NLD obstruction.
  Inflammatory e.g. trachoma, herpes, fungal.
  Traumatic e.g. bony fractures, surgical trauma.
  Foreign body e.g. lashes
  Tumours e.g. nasal polyps, maxillary tumours.
   CLINICAL EVALUATION OF EPIPHORA
Exclude causes of excessive lacrimation.
Investigations:
 1. Regurgitation test: Reflux of pus or tears from the
    puncti in case of obstruction of the naso-lacrimal duct.
 2. Instill a drop of fluorescein in the conjunctival sac and
    a cotton pellet under the inferior turbinate of the nose.
 3. The lacrimal passage is irrigated with saline, if
    fluorescein is not recovered and saline does not reach
    the nose, there is complete block.
 4. Dacryocystography: A radiocontrast medium is
    injected and X-ray is done at intervals to detect filling
    of the lacrimal system.
 5. Plain X-ray: for diagnosis of tumors or fractures.
Treatment of Epiphora
1. Treatment of the cause: e.g. Ectropion and nasal
   causes of epiphora
2. Stenosis of puncti and canaliculi:

         Dilatation and probing

3. Obstruction of Nasolacrimal duct:
    a. Congenital obstruction:
      Hydrostatic massage
      Dilatation and probing
      Dacryocystorhinostomy
b. Acquired obstruction:

    Dilatation and probing usually fails
    Dacryocystorhinostomy
    Dacryocystectomy.

				
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posted:11/18/2011
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