80 ĐỀ THI THỬ TUYỂN SINH TIẾNG ANH VÀO 10 SỞ GD – ĐT THÀNH PHỐ HỒ CHÍ MINH NĂ...
Khalil seminar
1. Presented by- Dr. Mohd. Khalil Mansuri
Moderator- Dr. Eva Tirkey (M.S.)
2. definition
The lacrimal system is the physiological system contaning
the orbital structures for tear production and drainage.
3. Embryology
1. Lacrimal glands-
8 wedge shaped epithelial buds.
End of 2nd month
2. Lacrimal sac-
Surface ectoderm.
Lies in form of solid column of cells.
Canalization starts in
Sac-3rd month
NLD-6th month
Puncta-7th month
4. LACRIMAL system
It comprises the structures concerned with the :-
1) Formation of tears-
Main lacrimal gland
Accessory lacrimal glands
2) Transport of tears-
by lacrimal passage
Includes- Puncta
Canaliculi
Lacrimal sac
Nasolacrimal duct.
5. LACRIMAL GLAND
LOCATION-
Main Lacrimal Gland lies in the
fossa for lacrimal gland (FOSSA
LACRIMALIS) of the frontal bone
which lies in upper and outer
corner of orbit.
Inferiorly gland rests on globe of
eye.
6. LACRIMAL GLAND
Lateral horn of aponeurosis of the levator muscle
divides it into two parts.
1. SUPERIOR ORBITAL PART -
• large, almond shaped.
• 2 surfaces-superior & inferior .
• 2 borders-anterior & posterior.
• 2 extremes-medial & lateral.
2. INFERIOR PALPEBRAL PART –
• Small
• consists of 2-3 lobules.
7. DUCTS of lacrimal gland
About 10-12 ducts.
Passes downwards from
the main lacrimal gland.
Open in the lateral part of
superior fornix.
Some also open in the
lateral part of inferior fornix.
Since all the ducts traverse the palpebral lobe , excision of
this lobe is functionally equivalent to the excision of the
whole gland.
8. Accessory Lacrimal Gland
1. Glands of Krause:- sub conjunctival tissue of fornices about 40-
42 in the upper fornix
and 6-8 in lower fornix.
2. Glands of Wolfring:- Along
the upper border of Superior
tarsus (2-5) and lower border
of inferior tarsus (2-3).
3. Rudimentary accessory Lacrimal
Glands Present in caruncle,
plica semilunaris and Infraorbital
region.
9. BLOOD SUPPLY & LYMPHATIC DRAINAGE
Blood supply- lacrimal artery.
(branch of ophthalmic artery)
Venous drainage- lacrimal vein.
(drains into the superior ophthalmic vein)
- AV shunts are also present in periglandular connective tissue.
Lymphatic drainage- preauricular lymph node.
10. NERVE SUPPLY
SENSORY - lacrimal branch of ophthalmic division of
trigeminal nerve.
SYMPATHETIC – postganglionic cervical sympathetic
fibers , associated with internal carotid artery (carotid plexus).
SECRETOMOTOR – (facial nerve) superior salivary
nucleus situated in the brain stem (pons).
12. 1) LACRIMAL FOSSA –
6.5 mm broad
16.5 mm long
• Lower part of the medial
wall of orbital margin.
• formed by-
Lacrimal bone
Frontal process of maxilla.
Lacrimal crest of maxilla.
Lacrimal crest of Lacrimal bone.
BONY LACRIMAL PASSAGE
13. 2) NASOLACRIMAL CANAL
• extends from lacrimal fossa to
inferior meatus.
• OUTER wall-lacrimal sulcus of
maxilla.
• INNER wall-
- descending process of lacrimal
bone.
- ascending lacrimal process of
inferior turbinate.
• Avg. length of canal is 12.4 mm.
14. It includes –
Lacrimal puncta
Lacrimal canaliculi
Lacrimal sac
Nasolacrimal duct
MEMBRANOUS LACRIMAL PASSAGE
15. LACRIMAL PUNCTA
Two in number (one in each lid )
Each puncta situated upon a straight elevation called PAPILLA
LACRIMALIS, which becomes
prominent in old age .
Puncta are surrounded by a
ring of fibrous tissue which
keep them patent.
Upper punctum is 6mm.
Inferior punctum 6.5 mm.lat. To medial canthus
when the eyelids are closed puncta do not overlap each other.
16. LACRIMAL CANALICULI
Superior and inferior canaliculi.
Joins the puncta to the lacrimal sac.
Diameter- 0.5 mm & two parts
VERTICAL-2mm.
HORIZONTAL-8mm.
These two parts lie at right angle to each other.
90% -forms a common canaliculus.
(internal common punctum)
Common canaliculus-opens in a small diverticulum of sac
LACRIMAL SINUS OF MAIER
In 10% individuals each canaliculus enters the sac separately .
17. Lacrimal Sac
Placed in the Lacrimal fossa located in the ant. Part of Medial
orbital wall.
Sac is closed above and open
below where it is continuous
with the Naso Lacrimal duct.
The Lacrimal sac enclosed by
Lacrimal fascia which is the
part of periorbital fascia.
18. when distentened it is about 15 mm length and 5-6 mm in width
with a capacity 20 cc.
Sac divided into three parts:-
A) Fundus:- it is about
3-5 mm.
B) Body :-10-12mm
C) Neck:- small and
narrow part
19. Lacrimal Sac (RELATIONS)
1. Medially:-
Upper Part- Ant. Ethmoidal air cells.
Lower Part- Middle meatus of nose.
2. Anterolateral (from deep to superficial)
(a) Lacrimal fascia and few fibers of inferior
oblique muscle.
(b) Horner’s muscles
(c) medial palpebral ligament
(d) palpebral fibres of orbicularis
(e) Angular Vein
20. Angular Vein:-
Lying under the skin it crosses the
medial palpebral Ligament 8mm from
the medial canthus.
therefore to avoid profuse bleeding
during sac surgery incision should not
be made more than 2-3 mm medial to
the medial canthus.
(f) skin is the most anterior relation.
21. Posteriorly:- From the Ant to post-
a) Lacrimal fascia
b) Horner’s Muscle
c) Septum Orbitale-which separates the sac from
the orbital fat .
d) Ligament of the Medial Rectus Muscle.
22. NASOLACRIMAL DUCT
Length: - may varies from 12-24 mm
Diameter:- About 3 mm
Divided into two Parts:-
a) Intra osseous part:- lying in the
Naso-lacrimal canal (12.4 mm ).
b) Intra Meatal Part:- lying within
the mucous membrane of the
lateral wall of the nose (5.32mm)
Direction of the NLD is downwards and backwards and laterally.
23. NLD- inferior opening is called ostium lacrimali.
Lumen narrow and long in female.
Broad and short in male.
In females perimenopausal & menopausal changes causes
shredding of epithelial cells, which may leads to blockage of
NLD.
Dacryocystitis is more common in female.
24. Valves of NLD
Lumen of NLD is marked by numerous folds of mucous
membrane called as valves.
1. Valve of ROSENMULLER.
2. Valve of BOCHDALEK.
3. Valve of KRAUSE or FERAUD.
4. Valve of TAILLEFER.
5. Valve of HASNER.
6. Valve of FOLTZ.
7. Valve of medial palpebral ligament.
25. HISTOLOGY
Lacrimal sac and NLD are lined by-
1. Epithelium- two layers of cells
Superficial Layer- Non-ciliated columnar cells and
contains Goblet cells.
Deep Layer- Flattened cells.
2. Subepithelial Tissue- contains lymphocytes.
3. Fibroelastic Tissue.
4. Plexus of vesseles-well developed around NLD.
26. Blood Supply of the Lacrimal Passage
Arterial supply :- Derived from three sources.
1) From ophthalmic Artery.
2) From the angular branch of facial artery.
3) From the Internal maxillary Artery.
Venous Drainage:- angular vein and infra orbital vein from above
and Nasal vein from below.
Lymphatics :-drain into the submandibular and deep cervical
glands.
27. Nerve Supply of the Lacrimal Passage
1) Sensory :- Trigeminal nerve.
Canaliculi, SAC, and upper part of duct-
infrartroachlear Branch of nasocilliary nerve.
Lower Part of the Duct- Ant. Superior alveolar
Nerve.
2) Motor :- from the branch of facial nerve which supply the
orbicularis muscles.
3) Sympathetic :- from sympathetic outflow of the orbit.
28. Jones lacrimal pump
Tears flow-along the upper and lower
marginal strips and enter the upper
and lower canaliculi by capillarity
and also by suction .
With each blink, the pretarsal
orbicularis oculi compress the
ampullae. Shortens the horizontal
canaliculi and moves the puncta
medially.
29. Simultaneously contraction of lacrimal part of orbicularis oculi causes
expansion of lacrimal sac, thereby creating a negative pressure which
sucks the tears from the canaliculi into the sac
• When the eyes open
the muscles relax,
the sac collapses
and a positive
pressure is created
which forces the
tears down the
nasolacrimal duct
into the nose.
30. Disorder of secretion-
HYPERSECRETION:-
Primary Hyperlacrimation-d/t direct stimulation of the
lacrimal gland. eg.cysts, tumour.
Reflex Hyperlacrimation – results from stimulation of
sensory branches of 5th cranial nerve d/o irritation of cornea or
conjunctiva.
Central Lacrimation-(psychical lacrimation)-seen in
emotional stage and hysterical lacrimation.
Applied aspects of Lacrimal Gland
31. TEAR FILM
Wolff (1946) first described detail structure of tear film and given the term
precorneal film.
Tear Film consist of three layers-
1) Lipid Layer:- outermost
secreted by meibomian,
zeis & Moll glands(.1µm)
2) Aqueous Layer:- Secreted by
Lacrimal Glands (6.5-7.5µm)
3) Mucin layer:- secreted by conjunctival
goblet cells(.02-.05µm)
32. HYPOSECRETION- Serious lack of tear may result into
Dry eye - not a disease
it’s a symptom complex occuring as a sequele to
deficiency or abnormalties of tear film.
It is due to-
Aqueous deficiency
Mucin deficiency
Lipid deficiency
Impaired eyelid function
epitheliopathy
33. Drainage Dysfunctions
1. Epiphora – is overflow of tears onto the face, d/t insufficient
tear film drainage from the eyes.
* Malposition of Lacrimal Puncta.
* Obstruction anywhere in lacrimal passage.
* Lacrimal Pump Failure.
2. Mass or swelling in the Region of medial canthus.
34. Congenital anomalies of lacrimal gland
Alacrimia-congenital deficiency or absence of tear secretion.
Riley day syndrome
Acoustic neuroma
Anhydrotic Ectodermal dysplasia
Surgery of CPA
Aplasia of lacrimal gland- may lead to congenital alacrimia.
35. Swelling in Lacrimal Gland
a) Dacryoadenitis
-Inflammation of
lacrimal gland.
b) Mikulicz’s Syndrome:- Bilaterally symmetrical enlargement
of Lacrimal and Salivary Glands.
36. c) Dacryops:- cystic swelling
in upper fornix due to
retention of secretions
following blockage of
Lacrimal duct.
d) Tumors:-
Pleomorphic adenoma
is the commonest.
Swelling in Lacrimal Gland
37. Congenital Anomalies Of The Lacrimal Passage
1. Ectasia of lacrimal passage:- due to failure of normal fusion of nasal
and maxillary process.
2. Atresia of Lacrimal Passage:- failure of canalization.
3. Congenital occlusion of NLD:- more common in lower end, causes
epiphora .
In the foetus, NLD is a solid cord & gets canalized later.
In about 30% cases this canalization is delayed or
is absent at lower end.
38. During embryogenesis Canalization of solid columns of
ectodermal cells takes place by degeneration and shredding of
central cells.
Debris of these cells if remains may occlude sac and may cause
congenital mucocoele.
Incomplete canalization causes
blockage of NLD may leads
to congenital dacryocystitis.
39. Anomalies Of The Lacrimal Passage
• Congenital absence of punctum- d/t failure or incomplete
outbudding of nasolacrimal core.
• Punctal stenosis.
• Supernumerary puncta and canaliculi.
• Dacryoliths –acquired NLD blockage.
40. DISEASES OF LACRIMAL PASSAGE
Dacryocystitis - Inflammation of lacrimal sac.
• Acute -
• Chronic-
41. REFERENCES
Wolff’s anatomy of eye and orbit (1968 ed.)
Jack J. Kanski – clinical ophthalmology.
Duke Elder –system of ophthalmology.
Parson’s diseases of eye.
A. K. Khurana- anatomy and physiology of eye.
H. V. Nema – anatomy of eye and its adenexa.
www.emedicine .com.
www.ophthalmology.com.