Lacrimal system for undergraduates

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By/Mohamed Ahmed El Shafie

Assistant Lecturer in ophthalmology department KafrELShiekh University

The lacrimal system consists of two parts:

Structures that secrete tear fluid.

Structures that facilitate tear drainage.LACRIMAL SYSTEM

It lies beneath the superior temporal margin of the orbital bone in the lacrimal fossa of the frontal boneIt is neither visible nor palpable A palpable lacrimal gland is usually a sign of a pathologic change such as dacryoadenitis or tumors.LACRIMAL GLAND ANATOMY

The tendon of the levator palpebrae muscle divides the lacrimal gland into a larger orbital part (two-thirds) and a smaller palpebral part (one-third).LACRIMAL GLAND PARTS

Several tiny accessory lacrimal glands (glands ofKrause and Wolfring) located in the superior fornix secrete additional seroustear fluid.ACCESSORY LACRIMAL GLAND

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Tear Flow Physiology

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may be due to one of two causes: Reduced tear production in certain systemic disorders (such as Sjgrens syndrome and rheumatoid arthritis) or as a result of atrophy or destruction of the lacrimal gland. Altered composition of the tear film due to vitamin A deficiency, medications (such as oral contraceptives), or certain environmental influences (such as nicotine smoking, or air conditioning). The tear film breaks up too quickly and causes corneal drying and scarring.DRY EYE

Patients complain of Burning, reddened eyes, and excessive lacrimation (reflex lacrimation) from only slight environmental causes such as wind, cold, low humidity, or reading for an extended period of time. A foreign body sensation is also present. May be accompanied by intense pain. Vision is usually minimally compromised .DRY EYE SYMPTOMS

Bitots spots: interpalpebral conjunctival foamy patches associated with severe vitamin A & xerophthalmia

FLUORESCEIN DYE DISAPPEARANCE TESTInstill 2 drops of fluorescein dye in the conjunctival sac and observe after 2 minutes

Normally no dye is seenProlonged retention of dye indicate inadequate drainage

JONES TEST IInstill 2 drops 2% fluorescein dye in the conjunctival sac, place a cotton bud dipped in 1% xylocaine in the inferior meatus, inspect the bud after 5 minutes.

Positive test- patent passages (may be hypersecretion)

No staining- Negative test

JONES TEST IIIf Jones I is negative, do Jones II

Place a bud similarly and perform lacrimal syringing

Positive test- lacrimal pump failure

Negative test- mechanical obstruction

DACRYOCYSTOGRAPHYTo visualize the passage and know the exact site, nature and extent of block.Inject radioopaque material in the sac.Take X-rays after 5 and 30 minutes

Congenital nasolacrimal duct obstruction

Delayed canalizationCan be bilateralReflux of purulent material from punctum

Acute dacryocystitis

Acute inflammation of sac or pericystic area leading to acute pain, swelling, redness and watering from the eye.

No interference like syringing,probing etc.

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DacryocystorhinostomyDCR

Quiz

Signs of acute dacryocystitis:Dry eyesPainless swelling Redness &Watering

Nasolacrimal duct opens-in the nose- at:Superior meatus Middle meatusInferior meatus

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