SAC
ANATOMY-
2 parts-
1. Secretory part
2. Collecting part
Secretory part-
- LACRIMAL GLAND-
- Superotemporal part of roof of orbit in the lacrimal fossa
- LPS divides it into orbital & palpebral lobes
- Tubulo-alveolar gland
- N – 7 N
- GLANDS OF KRAUSE & WOLFRING-
UL-40-42
LL- 6-8
Collecting part / Lacrimal passage-
- 2 Lacrimal puncta –lie 6mm from inner canthus
- 2 Canaliculi-2mm-vertical & 6-8mm horizontal
- Lacrimal sac- lies in the lacrimal fossa
-15mm long
-5-6mm wide
-Part above the MPL- Fundus
* Nasolacrimal duct-12-24mm long
-3-6mm wide
-2 parts-intraosseus & intrameatal
-Opens into inferior meatus of nose
*VALVE OF HASNER- at the lower end of NLD
-Prevents air entry into the sac wen air is blown with a closed nose
* VALVE OF ROSENMULLER- at the opening of common
Canaliculus into the sac.
LAYERS OF TEAR FILM-
- Outer lipid layer- [Meibomian gland]
- Middle Aqueous layer [Lacrimal gland]
- Inner mucin layer [ Goblet cells,Gld of Henle,Gld of Manz]
PHYSIOLOGY OF LACRIMAL DRAINAGE-[D-05]
Tears secreted by the main & accessory lacrimal gland→Variable amount drained by evaporation & the remainder as follows-
- Tears flow along the upper & lower marginal strips→enter upper &lower canaliculi by capillarity & suction.[70% drains-lower canaliculus]
- With each blink→pretarsal orbicularis compresses the ampullae →shortens the horizontal canaliculi →puncta moves medially
- Simultaneously,lacrimal part of orbicularis contracts & expands the sac→negative pressure→ sucks tears from canaliculi into the sac
- When the eyes open→ms relax→sac collapses→ positive pressure→forces the tears down the NLD into the nose
- Puncta move laterally→ canaliculi lengthen→ fill with tears
EPIPHORA-
Def- Overflow of tears d/t defect anywhere in the lacrimal drainage sys.
Causes-
- Ectropion
- Punctal stenosis/ occlusion
- Canalicular block
- NLD block
- Nasal polyp / tumour in inf meatus
- Lacrimal pump failure as in Bell’s palsy
LACRIMATION-
Def- Oversecretion of tears without any defect in drainage sys.
Causes-
- Emotional /Psychological
- Irritation of conj / cor by dust, fumes etc
- Nasal irritation by any chem.
- Exposure to bright light.
WATERING IN CHILDN-
- conjunctivitis
- Cong dacryocystitis
- Buphthalmos.
CHRONIC DACRYOCYSTITIS-
COMPLICATIONS-
- Acute exacerbation of chr dacryocystitis
- From ac dacryocystitis-
- Lacrimal abscess
- Lacrimal fistula
- Orbital / Facial cellulites
- Cavernous sinus thrombosis
- Lacrimal osteomyelitis
- Hypopyon cor ulcer
VIVA-Q. What is the dir of NLD?
- I PROBE LACRIMAL- Inferiorly-Posteriorly-Laterally
Q- Where does the NLD open ?
A-Inferior nasal meat
DACRYOCYSTORHINOSTOMY [D-03]
INDICATIONS-
- NLD block
- Chr dacryocystitis
- Mucocele
CONTRAINDICATIONS-
- Extreme old age
- Atrophic rhinitis
- Any growth in the sac
- Nasal polyps
- Hypertrophied inferior turbinate
- Dry eye syn
- blood dyscrasias
- Acute dacryocystitis
- Child < 3 yrs
PRE-OPER-
- Hb
- BT CT
- B. SUGAR
- BP
- ENT exam-atrophic rhinitis,nasal polyps,hypertrophied turbinates,DNS & malignancy
- NSAIDs & anticoag shud be stopped 3 days prior to surg
- Antibiotics & nasal decongestant drops 3 days prior to surg
TECH-
- Nasal packing-ribbon gauze soaked in xylocaine 2 % & adrenaline.Forcep shud be aimed at med canthus.Place the pack near the medial turbinate.Insertion of pack into post nasal cavity stimulates gag reflex & cannot achieve hemostasis.Never go superiorly & apply pressur→ damage the cribriform plate
- Anaesthesia- LA – adults & GA – childn & uncoop pts
- Skin Incision-8-10mm from medial canthus,2mm above the canthus & extending in a straight line for 3cm towards t.he ala of the nose . Avoid damage to the angular vein
- Expose the MPL & separate the ms fibres
- Expose the periosteum over the ant lac crest & reflect it
- Expose the lacrimal fossa & make initial bony puncture with blunt end of lacrimal dissector
- Enlarge the osteum with Citelli’s or Kerrison’s bone punch.[osteum is 15-17mm long,MPL to NLD]
- H- shaped incision is given on the sac & nasal mucosa & ant & post flaps made
- Ant & post flaps are sutured
10 Periosteum,orb & skin sutured
COMPLICATIONS-
- Bleeding
- Wound gape
- Fistula
- Scar / keloid
- Closure of anastomosis [ failed DCR]
- Osteomyelitis
- Infection
- suture abscess
FAILED DCR-
- Small osteotomy
- Blockage of anastomosis- improper suturing, redundant flaps,bony fragments,PO haematoma
- PO soft tiss inf
- Iatrogenic obstrn of common canaliculus
ENDONASAL DCR-
IND- Chr dacryocystitis with NLD block & mucocele
C/I- Sac tumours
-Dacryoliths
ADVANTAGES-
- No cutaneous scars
- Relatively bloodless surgery
- Less time
- Less edema
- Early recovery
- Medial canthal anatomy undistutbed
- BL DCR at the same sitting
- Can be done in acute dacryocystitis
- DCR can be combined with septoplasty for DNS
DISADVANTAGES-
- High cost of instrument
- Steep learning curve
- Intranasal manipulation may be needed [ inferior turbinate #, septoplasty]
LASER ASSISTED DCR-
Best lasers- Holmium YAG laser,
- Diode laser
DACRYOCYSTECTOMY-
INDICATIONS-
- Old age
- Any growth in the sac
- TB of sac
COMPLICATIONS-
All of the above except 5
- incomplete removal→ rec chr dacryocystitis
PROBING
Should be done bet 9-12 mo.
Prior to that ,spontaneous resolution is likely
Success rate decreases after the age of 1 year
Complications-
- Bleeding
- Failure to pass the probe d/t agenesis of NLD
Failure of probing twice is an indication for lacrimal intubation.
After the age of 3 yrs, DCR may be considered as bony dev is complete by then.
LACRIMAL GLAND TUMOURS-read from orbit
PLEOMORPHIC ADENOMA-
- Also k/as mixed cell tum
- Slow growing
- Encapsulation [ not a true capsule but results from compression of adjacent tiss]
- H/P- 2 components-1. Epithelial
2 Stromal
T/T- En bloc excision
Principle-Avoid biopsy to avoid seeding & rec
ADENOID CYSTIC CARCINOMA-
- MC malignant lacrimal gld tum
- Aggressive
- Invades Ns→ painful
Intracranial spread
- H/P-
Swisscheese pattern-Multiple lobules with pools of mucin
- T/T
Exentration with removal of adjacent bone + Radiotherapy
Q- D/Ds of lac fossa mass-
1.Lac gld tum
2.sarcoidosis
3 Lymphoma
PLEOMORPHIC ADENOMA
|
ACC
|
Slow
|
Rapid
|
Painless
|
Painful
|
CT scan-Encapsulation &
|
Unencapsulated
|
-bone erosion
|
Bone destruction
|
DRY EYE- notes
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