1. 1. LACRIMALAPPARaTUS DIFFERENT STRUCTURES, TEAR FILM AND LACRIMAL PUMP Suraj Chhetri B. Optometry 16th batch
2. 2. PRESENTATION LAYOUT Introduction Embryology Anatomy Secretory lacrimal apparatus Excretory lacrimal apparatus/ lacrimal passage Physiology Lacrimal pump mechanism & tear film Clinical co-relations 2/77
3. 3. INTRODUCTION Lacrimas in latin : a tear Lacrimal gland is exocrine gland Secretes aqueous component of tear It is located under the superotemporal orbital rim in a shallow fossa of the frontal bone. 3/77
4. 4. EMBROYOLOGY Lacrimal gland Starts to develop from multiple solid ectodermal buds arising from the basal cells of conjunctiva in the superotemporal region of fornix at 6th-7th weeks Mesenchyme surrounds these buds and proliferates to form the parenchyma of the lacrimal gland Buds branch and canalize to form ducts and alveoli 4/77
5. 5. At 5th month of gestation lateral horn of levator aponeurosis divides it into palpebral and orbital part Lacrimal glands do not function fully until approximately 6th week of life Accessory lacrimal glands are formed from ectodermal invagination of conjunctiva which detected at 6 to 7 months 5/77
6. 6. Lacrimal passages Developed along the line of cleft between lateral nasal & maxillary process at 32 days 6/77
7. 7. Nasolacrimal duct Maxillary process grows medially to override paraxial mesoderm of the nasolacrimal process Nasooptic fissure is thus formed Surface ectoderm within the fissure thickens in a cord-like fashion 7/77
8. 8. cords of epithelium invaginate at the upper and lower lid margins, eventually forming the canaliculi. These epithelial cords fuse to form the nasolacrimal drainage system. 8/77
9. 9. CONGENITAL ABNORMALITIES Dacryostenosis Absence of valves Congenital fistula of lacrimal sac Punctal agenesis Double puncta Atresia of canaliculi 9/77
10. 10. Anatomy of lacrimal apparatus Secretory lacrimal apparatus: Main lacrimal gland Accessory lacrimal gland: glands of Krause & glands of wolfring. Excretory lacrimal apparatus: Lacrimal punctum Lacrimal canaliculus Lacrimal sac Nasolacrimal duct 10/77
11. 11. Anatomy of lacrimal apparatus 11/77
12. 12. Main lacrimal gland (Tear gland) SITE- in lacrimal fossa formed by orbital plate of frontal bone in the anterolateral roof of orbit SHAPE-almond shaped TYPE-exocrine PART-superior orbital and inferior palpebral part Separated by lateral horn of aponeurosis of levator muscle. 12/77
13. 13. Structure of lacrimal gland Branched tubulo-alveolar gland Similar to salivary gland Microscopically, it has glandular tissue, stroma & septa. 1)Glandular tissue: consists of acini and ducts arranged in lobes and lobules. This lobules joins to form intralobular ducts which finally joins to form extralobular ducts. 13/77
14. 14. 2)Stroma: connective tissue, elastic tissue, lymphoid tissue, plasma cell, nerve terminals and blood vessels 3)Septa: fibrovascular in nature and separates lobes and lobules from each other 14/77
15. 15. Acinar unit (secretory unit) Columnar or pyramidal shaped secretory cells (luminal surface of the secretory cell has microvilli) Central lumen Surrounding basal layer of myoepithelial cells (aid in expulsion of secretion ) 15/77
16. 16. Clinical significance 1. Acute dacryoadenitis Inflammation of lacrimal gland. Develop as primary inflammation of the gland or secondary to some local infection as in trauma, conjuctivitis(especially gonococcal and staphylococcal) and orbital cellulitis or systemic infection like mumps, infleunza, measles. Clinical feature: inflammation of palpebral part, painful swelling in lateral part of upper lid, typical S- shaped curve of lid. 16/77
17. 17. 2. Chronic dacryoadenitis (mikuliczs syndrome) A chronic enlargement of lacrimal gland secondary to systemic disease and associated with salivary gland enlargment 17/77
18. 18. PLEOMORPHIC ADENOMA RE lacrimal gland malignant Mixed tumor (carcino sarcoma) 18/77
19. 19. Accessory Lacrimal gland Glands of Krause: In the subconj. tissue near fornices. About 40-42 in upper lid, 6-8 in lower lids. More numerous laterally. Supply aqueous phase of basal tear film. Glands of wolfring: Situated near upper border of superior tarsus plate, 2-5 in upper lid. lower border of inferior tarsus, 2-3 in lower lid Supply aqueous phase of the basal tear film. 19/77
20. 20. LACRIMAL DUCTS 10-12 lacrimal ducts 2-5from orbital portion 6-8 from palpebral portion The ducts from the orbital portion joins with the palpebral portion & finally open into the superior fornix approx.5mm above the lateral tarsus border Clinical importance: Removal or damage even only to the palpebral portion of the gland amounts to the excision of the entire gland as far as secretory function is concerned 20/77
21. 21. Clinical importance Lacrimal ductal cyst(dacryops) Cystic swelling , which occur due to retention of lacrimal secretion following blockage of the lacrimal ducts 21/77
22. 22. Blood supply: Supplied by lacrimal artery - ophthalmic artery internal carotid artery. Sometimes transverse facial artery & infraorbital artery supplies The lacrimal vein joins to the superior ophthalmic vein 22/77
23. 23. Lymphatic drainage Lymphatics from the gland passes to the conjunctival channels hence to the preauricular lymph nodes. 23/77
24. 24. Nerve supply Sensory: from lacrimal nerve ophthalmic branch of trigeminal nerve(fifth cranial nerve) Symphathetic: from carotid plexus of cervical symphathetics. Secretomotor: from superior salivary nucleus. 24/77
25. 25. Excretory Apparatus: Lacrimal puncta Lacrimal canaliculi Lacrimal sac Nasolacrimal duct 25/77
26. 26. Lacrimal punctum Small rounded or oval opening. In upper and lower eyelid at junction of ciliary and lacrimal portion of lid margin Upper-6mm and lower 6.5mm later to inner canthus On closure of eyelid punctum do not overlap 26/77
27. 27. Contd Each punctum sits on top of an elevated mound known as the papilla lacrimalis. They are relatively avascular in comparison to the surrounding tissue, giving them a pale appearance, which is accentuated with lateral traction of the lid. This pallor can be helpful in localizing a stenosed punctum. 27/77
28. 28. Lacrimal canaliculi LENGTH-Each are 8-12mm long LENGTHCOURSE-2mm vertical&8-10mm horizontal. UNION-90% they unite as a common canaliculus and in about 10% opens separately in lateral wall of the orbital sac. VALVE-Valve of Rosenmuller,a mucosal fold overhangs the junction between common canaliculi and prevents reflux. 28/77
29. 29. ANGLE- between the vertical and horizontal segments is approximately 90 degrees, and the canaliculi dilate at the junction to form the ampulla.. LININGS-by nonkeratinized stratified squamous epithelium and are surrounded by elastic tissue, which permits dilation to 2 or 3 times the normal diameter. CLINICAL SIGNIFICANCE An incompetent valve of rosenmullar is observe clinically as air escaping From the lacrimal puncta when the indivisual blows his or her nose 29/77
30. 30. Canaliculitis Inflammation of canalaiculi. Casuative agent: actinomyces israelii. Presentation: unilateral epiphora with chronic mocopurulent conjuctivitis. Signs: pouting punctum, pericanalicular inflammation, mucopurulent discharge on pressure over the canaliculus. Concretions consisting of sulphur granules can be expressed. 30/77
31. 31. Oedema and pouting of punctum Expressed concretions with sulphur granules 31/77
32. 32. LACRIMAL SAC Site lacrimal fossa: (anterior part of medial orbital part) where sac is encovered by lacrimal fasica (periorbita i.e periosteum lining of orbit) Length: 15mm Volume : 20cc Parts :fundus (3-5mm) , body (10-12mm) & neck Lining of double layer epithelium (upper is columnar and deeper is falter) 32/77
33. 33. Relations Medial to sac separated by periorbita and bone lie anterior ethmoidal sinuses Below it lies: nasal middle meatus Lateral to it lies skin ,part of orbicularis oculi, lacrimal fascia Anteriorly lies the medial palpebral ligament & angular vein Posterior to sac lies lacrimal fasica & septum orbitale 33/77
34. 34. CLINICAL SIGNIFICANCE Dacryocystitis Inflammation of lacrimal sac. Acute and chronic form. Usually is secondary to NLD obstruction. Also congenital which is secondary to NLD blockage. 34/77
35. 35. Acute dacryocystitis Chronic dacryocystitis presentation: subacute pain, redness and swelling at medial canthus. Sign: very tender, red, tense swelling,can be associated with mild preseptal cellulitis, abscess formation , fistula formation. Causative agent: streptococcus, pneomococcus and staphylococcus. Presentation:epiphora with mucocele Signs: painless swelling at inner canthus, mucoid fluid regurgitate on pressing the swelling area. Causative agent: satphylococci, streptococci, pneumococci 35/77
36. 36. Acute Dacryocystitis 1. 2. fistula formation 36/77 Cellulitis stage Fistula formation mucocele formation
37. 37. Chronic dacryocystis Painless swelling at inner canthus expression of mucopurulent discharge 37/77
38. 38. Nasolacrimal duct Length-18 mm Diameter-3mm Upper end- narrowest Direction- downwards, backward & laterally Parts-Intraosseous part 12.5mm & Intrameatal 5.5mm 38/77
39. 39. Contd Lower end- opens into the nose through an ostium under the inferior turbinate, covered by valve of Hasner. 39/77
40. 40. Blood supply and nerve supply to lacrimal passage Superior and inferior palpebral arteries (ophthalmic artery) and also by infraorbital artery , angular artery &branch of sphenopalatine artery Infratrochlear nerve ophthalmic division of trigeminal nerve and also by anterior superior alvolar nerve 40/77
41. 41. CLINICAL IMPORTANCE CNLDO (Congenital nasolacrimal duct obstruction)-failure of the canalization of the NLD after birth In fetus, the NLD is a solid cord of cells, which gets canalized at birth. In 30% of new borns canalization is delayed. This congenital NLD blockage causes epiphora predisposing to congenital dacryocystitis. PANDO (primary acquired nasolacrimal duct obstruction)-an entity of nasolacrimal duct obstruction caused by inflammation or fibrosis without any precipitating cause.. studies have revealed inflammation, vascular congestion, and edema of the nasolacrimal duct in the early phases and, ultimately, fibrosis with complete occlusion of the nasolacrimal duct's lumen in the late phases. 41/77
42. 42. SALDO(secondary acquired lacrimal drainage obstruction) has some etiology : infectious Bacteria such as Actinomyces Fusobacterium Bacteroides Mycobacterium Chlamydia 42/77
43. 43. Congenital nasolacrimal duct obstruction Epiphora and matting Infrequently acute dacryocystitis Massage of nasolacrimal duct and antibiotic drops 4 times daily Improvement by age 12 months in 95% of cases If no improvement - probe at 12-18 months Results - 90% cure by first probing and 6% by second Treatment 43/77
44. 44. Remnants of epithelium within the cords form inconsistent valve like folds which are diagrammatically represented . 1, valve of RosenMuller 2, valve of Krause 3, spiral valve of Hyrtl 4, valve of Taillefer 5, valve of Hasner or plica lacrimalis. 44/77
45. 45. Physiology of lacrimal appartus 45/77
46. 46. Secretion of tears Continously secreted through out the day by main &accessory lacrimal gland Rate of tear production -1.2microl/min tear vol.-7 micro lit 2 Components: Basic Secretors Reflex Secretors 46/77
47. 47. Basic Secretors mucin secreting goblet cell of conjunctiva Accessory lacrimal gland of krause & Wolfring tarsal gland Gland of Zeiss & Moll 47/77
48. 48. Reflex secretion due to irritation of 5th cranial nerve in response to sensation from cornea and conjunctiva.(mainly by lacrimal gland) 48/77
49. 49. Tears Lost Absorbtion from conjunctiva Evaporation Size of palpebral aperture Blink rate Ambient temperature and humidity Nasolacrimal drainage Any obstruction on pathway 49/77
50. 50. Lacrimal pump mechanism The secreted tear flows over the ocular surface and reaches marginal tear strip running along the ciliary margin of each eyelids and collects as lacrimal lacus in inner canthus. From there it is drained to nasal cavity via lacrimal excretory system by active lacrimal pump mechanism. 50/77
51. 51. Working of lacrimal pump mechanism Operates with the blinking movements. Performed by orbicularis muscle of eyelid. Two major events Eyelid closure eyelid open 51/77
52. 52. On eyelid closure following events occur concomitantly Contraction of pretarsal fibres of orbicularis compress the ampulla and shortens the canaliculi. This movement propels the tear fluid present in the ampulla and horizontal part of canaliculi toward the lacrimal sac Contraction of preseptal fibres pulls the lacrimal fascia and lateral wall of the sac laterally thus opening the normally closed lacrimal sac. This produces negative pressure and draws the tear from canaliculi to lacrimal sac. At the same time inferior portion closes more tightly thus preventing aspiration of air from nose. 52/77
53. 53. On eyelid opening following events occur concomitantly Relaxation of pretarsal fibres allows canaliculi to expand and reopen. This draws the tearfluid through the punctum from the lacrimal lake. Relaxation of preseptal fibres allows the lacrimal sac to collapse which inturn expels the fluid downard into open NLD. At the same time puncta moves laterally, canaliculi lengthens and is filled with tears. 53/77
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55. 55. Drainage into the nasal cavity Gravity Air current movement within the nose Final entry of tears into the nose :facilitated by opening of Valve of Hasner which widens synchronously with opening of lids 55/77
56. 56. Tear film It consist of three layars 1. Mucous layer: subconjunctival goblet cells 2. Aqueous layer: main and accessory lacrimal glands 3. Lipid layer :Meibomian gland Gland of Zeis and Moll 56/77
57. 57. Lipid layer Outermost layer Secreted by meibomian gland, zeiss and moll gland Thickness-0.1micrometre Consist of polar and nonpolar lipid This layer prevents the overflow of tear and also evaporation of tear 57/77
58. 58. Aqueous layer Middle layer. Secreted by lacrimal gland and accessory gland of krause. Thickness: 6.5-7.5 micrometre. Constitute main bulk of tear. Consist of inorganic salts, glucose, urea, and various biopolymers like proteins(Ig A), antibacterial agent( lysozyme, lactoferrin). This layer serves to provide atmospheric oxygen to epithelium,washes away debris and noxious agent, maintain the normal level of electrolyte over occular surface epithelium. 58/77
59. 59. Mucin layer Innermost layer Secreted by conjuctival goblet cells This layer makes the hydrophobic corneal surface hydrophilic overwhich the aqueous and lipid layer get adheres. Thus plays a vital role in stability of tear film Act as lubricant during eye movement 59/77
60. 60. Tear film abnormalities Dry Eye It is the state of abnormal tear film that can be caused by number conditions which alter its composition and affect stability. Normal tear Tear in dry eye 60/77
61. 61. Tear film abnormalities classification on the basis of physiological consideration: (holly and lemp ) Aqueous deficiency Mucin deficiency Lipid abnormality Impaired lid function epitheliopathy 61/77
62. 62. Tests for tear film adequacy Schirmer test: assess aqueous tear production. Performed with whatmann 41 filter paper. Two type: Schirmer I: without anesthesia Normal lower limit is 10mm of wetting after 5min Schirmer II: use of anesthesia Normal lower limit is 6mm after 5min 62/77
63. 63. Tear film break-up time Indicate adequacy of mucin component of tear It is the time interval between complete blink and appearance of first randomly distributed dry spot on cornea. Done by instillation of fluorescein drop 2% or impregnated fluoresceinstrip. Examined under cobalt blue light of slit lamp. TBUT value less than 10 sec is said to be dry eye. 63/77
64. 64. Clinical correlation of lacrimal apparatus Watering eye Implies overflow of the tears from conjuctival sac Occur due to : Excessive secretion of tears(hyperlacrimation) Obstruction of lacrimal passage 64/77
65. 65. Clinical evaluation of watering eye 1. External Ocular examination with slit lamp: Ectropion entropion Punctal obstruction by an eyelash Large carauncle displacing punctum away from globe Pouting punctum Any occular FB 65/77
66. 66. 2.Regurgitation test A steady pressure with index finger over lacrimal sac area is applied. Punctal reflux of mucopurulent material on compression indicates patent canalicular system with obstruction at lacrimal sac or NLD 66/77
67. 67. 3. Fluorescein dye disappearance test(FDDT) Performed with instillation of 2% fluorescein dye in both conjuctival fornices. Observations made after 2 min. No dye is seen in conjuctival sac-patent passage Retention of dye inadequate drainage due to atonia of sac or mechanical obstruction. 67/77
68. 68. 4. Lacrimal syringing test Local anesthetic(4% xylocaine) is instilled Punctum is dilated if narrow Gently curved, blunt tipped lacrimal cannula on a 2mm saline filled syringe is inserted into lower puncta and advanced few mm following the contour of the cannulus prior to irrigation 68/77
69. 69. Then after, normal saline is pushed into lacrimal sac . The following conditions are obtained: 1. Free passage of saline indicate patency of lacrimal passage. 2. Clear fluid from same puncta indicate same pucta block. 3. Clear fluid from opposite puncta indicate common camnalicular block. 4. Mucoid fluid from opposite puncta indicate NLD block. 69/77
70. 70. Probe test The hard stop and soft stop is encountered Hard stop indicates the patency of lacrimal canaliculi Occurs when cannula enters the lacrimal sac but comes to stop at the medial wall of sac Soft stop indicates the non-patency of canaliculi Occurs when cannula donot enter lacrimal sac and presses the soft tissue of common canaliculus 70/77
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72. 72. 5. Jones dye testing Performed in patients with suspected partial obstruction of the drainage system. Type: John testI: differentiate between watering due to partial obstruction and hypersecretion of tear. John test II: identifies probable site of partial obstruction. Done after John I. Two drops of 2% fluorescein dye is instilled in conjuctival sac and a cotton bud dipped in 1% xylocaine is placed in inferior meatus after 5 min. John test I: Positive: fluorescien is recovered from the nose indicating patency of drainage system. Watering is due to primary hypersecretion. Negative: no dye is recovered indicating a partial obstruction. In this case John II is recommended. 72/77
73. 73. John test II: Cotton bud is placed in inferior meatus and syringing is performed after application of anesthetic. Positive: fluorescein stained saline is recovered from nose. Here fluorescein has entered in sac thus conforming patency of upper lacrimal passage. Negative: unstained saline is recovered from the nose. It indicates no entry of dye in lacrimal sac and implies partial obstruction of puncta, canaliculi or common canaliculus. 73/77
74. 74. Introduction to obstruction of lacrimal passage Punctal obstruction: Primary punctal stenosis: caused in absence of punctal eversion e.g due to chronic blepharitis, herpes simplex, herpes zooster, cicatrizing conjuctivitis, trachoma etc Secondary punctal obstruction: caused by punctal eversion. 74/77
75. 75. Canalicular obstruction: Occurs due to congenital trauma, herpes simplex infection, drugs and chronic dacryocystitis. Nasolacrimal duct obstruction: Congenital,idioapthic, naso- orbital trauma,granulomatous disease like sarcoidosis,infiltration by nasophyrangeal tumors. Dacryoliathiasis: lacrimal stone in any part of lacrimal system. 75/77
76. 76. References 76/77
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78. 78. Birthday special Bikash