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عرض

The Lacrimal System

Anatomy
1.The puncta
2.The canaliculi
3.lacrinal sac
4.Nasolacrimal duct

Causes of watering Eye

1.hypersecretion secondary to ocular inflammation and surface disease.
2.defective drainage
a.Malposition of the lacrimal puncta e.g. secondary to ectropion

b.obstructionany where along the lacrimal drainage system.

3. lacrimal pump failure

Obstruction

1.primary punctual stenosis . seen in :

a.infections e.g. herpes simplex and trachoma

b.post irradiation for malignant lid tumors.

c.cicatrizing conjunctivitis.

2.secondary to medial ectropion .

LACRIMAL SYSTEM

Treatment:

1. For primary punctual stenosis dilatation with nettleship dilator or punctoplasty.
2. For the secondary punctual stenosis:

a.Zeigler cautery burns to the medial palpebral conjunctiva 5mm below the punctum.

b.medialconjunctivoplasty

Canalicular obstruction

Causes are similar to those of primary punctual stenosis.
Treatment:
a.partial obstruction treated by intubation.
b.total obstruction may be treated with canaliculodacryocystorhinostomy (CDCR).

nasolactimal duct obstruction

causes :
1.idiopathic is by far the most common.
2.secondary
a.nasoorbital trauma.
b.wegenergranulomatosis
c. infiltration by nasopharyngeal tumours.
Treatment:
Dacryocystorhinostomy.

Congenital nasolacrimal duct obstruction(delayed canalization)

It result from delayed canalization of the nasolacrimal duct at the valve of Hasner.
Present with Epiphora and matting of the lashes ,starting soon after birth.

Treatment:

1.massage of the lacrimal sacand duct.
2.probing :this should be delayed until the age of 12 months because spontaneous canalizationoccurs in about 95% of cases.

LACRIMAL SYSTEM

Dacryocystitis

acute or chronic
most commonly staphylococcal or streptococcal.

Acute dacryocystitis

Usually secondary to nasolacrimal duct obstruction
Treatment
Systemic antibiotics and warm compresses
DCR after acute infection is controlled

Chronic dacryocystitis

Epiphora and chronic or recurrent unilateral conjunctivitis
Treatment - DCR

Dry Eye

The Tear film
It has three layers:
1.Outer Lipid layer secreted by the meibomian gland
2.Middle Aqueous Layer secreted by the main and accessory lacrimal glands.
3.Inner Mucin secreted by the conjunctival goblet cells

classification

(a)hyposecretive (Sjogren or non-Sjogren)
1.Sjogren
a. Primary is associated with a dry mouth (xerostomia) and auto-antibodies.

b.Secondary is associated with a systemic autoimmune connective tissue disorder :

1.Rheumatoid Arthritis
2. SLE
3.Psoriatic arthritis
4.Dermatomyositis and polymyositis
2.non-Sjogren e.g.age related
(b) evaporative
a. Oil deficiency secondary to meibomian glands dysfunction e.g. posterior blepharitis

b.Defective resurfacing as a result of abnormal lid-globe congruity or defective blinking.

Diagnosis
Symptoms include irritation, foreign body sensation, burning, presence of stringy mucous discharge and transient blurring of vision.
Signs include abnormal tear minscus and inferior punctate corneal epithelial erosion.

Treatment

1. patient education regarding the avoidance of environmental factors and toxic drugs that may exacerbate the symptoms .
2. tear substitutes in the form of tear drops,gelor ointments
3. topical cyclosporine (0.05%,0.1%) reduces cell mediated inflammation of lacrimal tissue.

Done by Omar Abid ALsamrrae

^_^ as simple as life


رفعت المحاضرة من قبل: عادل احمد هلال الجميلي
المشاهدات: لقد قام 14 عضواً و 85 زائراً بقراءة هذه المحاضرة






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