The document outlines the structure and function of the tear film, highlighting its three layers: mucus, aqueous, and lipid. It discusses dry eye conditions, their causes, clinical features, and diagnostic tests. Treatment methods for dry eye include tear substitutes, anti-inflammatory medication, and interventions to reduce tear evaporation.

1. TEAR FILM
AND
DRY EYEPRESENTER: SURAJKCMBBS
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2. Structure of tear film
• Wolff was the first to describe the detailed
structure.
• Named precorneal film
• Three layers:
1) mucus layer
2)aqueous layer
3) lipid layer
Posterior
To
Anterior
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3. 3

4. Layers of tear film
1. Mucus layer.
• innermost and thinnest stratum of the tear
film.
• consists of mucin secreted by conjunctival
goblet cells and glands of Manz.
• converts the hydrophobic corneal surface into
hydrophilic .
• Helps in lubrication
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5. Layers of tear film
2 . Aqueous layer:
• intermediate layer which consists of tears
secreted by the main and accessory lacrimal
glands.
• The tears mainly comprise of water and small
quantities of solutes such as sodium chloride,
sugar,urea and proteins.
• It also contains antibacterial substances like
lysozyme, betalysin and lactoferrin.
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6. Layers of tear film
3 Lipid or oily layer:
• This is the outermost layer of tear film formed
at air-tear interface
• Secreted by : Meibomian, Zeis, and Moll
glands.
• prevents the overflow of tears, retards their
evaporation and lubricates the eyelids
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7. Functions of tear film
• 1. Keeps the cornea and conjunctiva moist.
• 2. It provides oxygen to the corneal
epithelium.
• 3. Washes away debris and noxious irritants.
• 4. Prevents infection due to presence of
antibacterialsubstances.
• 5. Facilitates movements of the lids over the
globe.
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8. Dry eye
Dry eye occurs when there is inadequate tear
volume or function resulting in an unstable tear
film and ocular surface disease.
1 Keratoconjunctivitis sicca (KCS) refers to any eye
with some degree of dryness
2 Xerophthalmia describes a dry eye associated
with vitamin A deficiency.
3 Xerosis refers to the extreme ocular dryness
and keratinization that occurs in eyes with severe
conjunctival cicatrization.
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9. ETIOLOGY
 Accroding to International Dry Eye Workshop
report 2007 , causes can be divided into :
1) Aqueous deficiency dry eye
2) Evaporative dry eye
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10. Aqueous deficiency
dry eye
Sjogren’s
syndrome
Non sjogren’s
syndrome
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11. Sjogren’s syndrome
• Autoimmune inflammation and destruction of
lacrimal and salivary glands
• Occurs in women between 40- 50 years
• Primary sjogren’s : combonation of
keratoconjunctivitis sicca and xerostomia
• Secondary sjogrens : dry eye/ dry mouth and
autoimmune disease commonly rheumatoid
arthritis
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12. Non sjogrens syndrome
1) Primary age related hyposecretion
2) Lacrimal gland deficiencies
3) Duct obstruction : chemical burn , old
trachoma ,
4) Reflex hyposecretion : parkinsons disease ,
Riley day syndrome , reflex sensory block , 7th
cranial nerve damage , reduced corneal
sensation
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13. Evaporative dry eye
1. Meibomian gland dysfunction : chronic
posterior blepharitis , congenital absence of
meibomian
2. Lagophthalmus : facial nerve palsy , severe
ptosis , eyelid scarring , symblepharon
3. Defective blinking :
4. Vitamin A deficiency
5. Other factors affecting ocular surface : topical
drugs , contact lens , scarring disorder
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14. Clinical features
 Irritation
 foreign body sensation
Itching
Non specific ocular discomfort
Feeling of dryness
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15. Clinical features
Signs :
Tear film signs : stingy mucous , marginal tear
strip is reduced, froth in the tear
Conjunctival sign : lustureless , mild
congestion , xerosis and keratinisation may
occur
Corneal signs : punctuate epithelial erosion ,
filaments or mucus plaques ,
Signs of causative disease :
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16. Conjunctival
Signs
Hyperemia Bitot’s spots
Symblepheron
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17. CORNEAL
SIGNS
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18. Approach to dry eye
1 ) HISTORY
2) PHYSICAL EXAMINATION
3) INVESTIGATIONS
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19. 1. Tear film break-up (BUT).
 Interval between a complete blink and appearance
of first randomly distributed dry spot on the cornea.
 Noted after instilling a drop of fluorescein and
examining in acobalt-blue light of a slit-lamp.
 Indicator of adequacy of mucin component of tears.
 Normal values : 15 to 35 seconds.
 Values less than 10 seconds imply an unstable tear
film
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20. TEAR BREAK UP TIME
15-34 sec Normal
<10 sec Abnormal
5-9 sec Borderline Dry eye
<5 sec Severe Dry Eye
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21. Schirmer-I test
 measures total tear secretions.
 performed with the help of a 5 × 35 mm strip of
Whatman-41 filter paper which is folded 5 mm
from one end and kept in the lower fornix at the
junction of lateral one-third and medial two-
third.
Normal values of Schirmer-I test are more than
15 mm.
 Values of 5-10 mm are suggestive of moderate to
mild keratoconjunctivitis sicca (KCS) and less than
5 mm of severe KCS.
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22. 23

23. 3. Rose Bengal staining
PATTERN INDICATION
C mild or
early cases with fine punctate stains
B moderate cases with
extensive staining
A severe cases with
confluent staining of conjunctiva and
cornea
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24. 25

25. Treatment
1) Supplementation with tear substitute :
 available in drop , ointment
slow release inserts
 most available tear drop contains
either cellulose derivatives
( 0.25 – 0.7 methy cellulose )
or polyvinyl alcohol
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26. 2) Topical cyclosporine (0.05% , 0.1% ) :
reduces cell mediated inflammation of lacrimal
tissues
3) Mucolytics : 5% acetyl cystine
disperses the mucus thread and decreases the
tear viscosity
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27. 4) Preserving the existing tears :
reducing the
evaporation
decreasing the drainage
( punctal occlusion )
Decreasing room temperature Collagen implants
Use of moist chamber and protective
glass
Cyanoacrylate tissue adhesives ,
electrocauterisation
Argon laser occlusion
Surgical occlusion
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28. 29

29. 5) Treatment of causative disease :
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30. COMPLICATION
• Corneal vascularisation
• Corneal opacities
• Recurrent infections
• Ocular surface keratinisation
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31. REFERENCES
• A K khurana comprehensive ophthalmology
6TH
• Kanski clinical ophthalmology 7th edition
• Color atlas of ophthalmology
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32. THANKYOU
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