Dry eye syndrome is a highly prevalent disease characterized by loss of tear film homeostasis. It can be classified as aqueous-deficient or evaporative dry eye. Aqueous-deficient dry eye includes Sjögren's syndrome dry eye and non-Sjögren's syndrome dry eye. The pathophysiology involves tear hyperosmolarity, tear film instability, and inflammation of the ocular surface. Diagnosis is based on patient history, examination findings, tear break-up time, ocular surface staining, and tear secretion tests. Treatment depends on disease severity and may include artificial tears, anti-inflammatory medications, punctal plugs, and secretagogues.

1. DRY EYE SYNDROME
PRESENTER – DR.BEMNET T.
MODERATOR – DR.YARED A.(MD ,MPH,
ASSOCIATE PROFESSOR OF OPHTHALMOLOGY,
SUBSPECIALTY IN ANTERIOR SEGMENT AND CORNEAL
DISEASE)

2. Out line
Introduction
Definition
Classification
Pathophysiology
Presentation
Diagnosis
Treatment

3. INTRODUCTION
• Dry eye syndrome is a highly prevalent and multifactorial disease of the
tear film and ocular surface
• Can cause problems ranging from mildly irritating to impaired vision
• And also can affect the outcome of corneal, cataract and refractive
surgeries
• Mostly symptoms of dry eye improves with treatment but usually its not
curable

4. DEFINITION
• The definition of dry eye syndrome is still under continues revision
• According to 2017 TFOS DEWS II Dry eye is:
“A multifactorial disease of the ocular surface characterized by a loss
of homeostasis of the tear film and accompanied by ocular symptoms,
in which tear film instability and hyperosmolarity, ocular surface
inflammation and damage, and neuro sensory abnormalities play
etiological roles. ”

5. CLASSIFICATION
In 2007/2017 international dry eye workshop (DEWS),classify dry eye into:
 Aqueous-deficient – is due to lacrimal gland dysfunction
Sjögren syndrome dry eye (primary or secondary).
Non- Sjögren syndrome dry eye.
 Evaporative
Intrinsic
Extrinsic

7. Cont.…
Aqueous deficient dry eye
Sjögren syndrome dry eye
 Is an autoimmune disorder characterized by lymphocytic
inflammation
 Mainly involving lacrimal and parotid gland but it also can affect any
exocrine gland.
 Inflammation block release of neurotransmitters or impact the
cellular response to neuromediators.
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8. Cont..
 The classic clinical triad consists of dry eyes, dry mouth and parotid
gland enlargement
 It can present as:
 Primary – when it present in isolation
 Secondary – when it present with another autoimmune disorder.

9. Cont..
Non - Sjögren syndrome dry eye
It can be due to:
 Lacrimal deficiency:
 Primary (e.g. Age-related dry eye , congenital alacrima , familial
dysautonomia ) or
 Secondary (e.g. Inflammatory and neoplastic lacrimal gland
infiltration, acquired immunodeficiency syndrome (AIDS), graft-
versus-host disease, lacrimal gland or nerve ablation).
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10. Cont..
Lacrimal gland duct obstruction
E.g. Trachoma, cicatrical pemphigoid, chemical injury, Stevens–johnson
syndrome.
Reflex hypo secretion: sensory
E.g. Contact lens wear, diabetes, refractive surgery, neurotropic keratitis
or motor block (e.g. Seventh cranial nerve damage, systemic drugs).
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11. Cont.…
Evaporative
Intrinsic
 Meibomian gland deficiency,
E.G. Posterior blepharitis , rosacea.
 Disorders of lid aperture,
E.G. Excessive scleral show, lid retraction, proptosis , facial nerve palsy.
 Low blink rate
E.G. Parkinson disease, prolonged computer monitor use, reading, watching television.
 Drug action,
E.G. Antihistamines, beta-blockers, antispasmodics, diuretics.
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12. Cont..
Extrinsic
○ Vitamin A deficiency.
○ Topical drugs including the effect of preservatives.
○ Contact lens wear.
○ Ocular surface disease such as allergic conjunctivitis
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13. Pathophysiology
• The well accepted theory is based on the concept of LFU
• The LFU Consist :
Ocular surface – cornea , conjunctiva and meibomian gland
Main and accessory lacrimal gland
Eye lid
Neural network – CN V AND VII
• OSM

14. Cont.…
Over all function of the LFU are:
Tear-film integrity
Ocular surface health
The quality of the image projected onto the retina
Any disturbance in the LFU will result in dry eye
The core mechanisms of dry eye are believed to be driven by
Tear hyperosmolarity
Tear-film instability, and
Inflammation.

15. Cont.…
Tear hyperosmolarity
Is a condition featured by dehydration resulting in increased osmotic
concentration
It can be caused due to:
Tear secretory dysfunction – afferent , efferent , glandular or inflammation of OS
or gland
Increased evaporation – both intrinsic and extrinsic factors
Age, hormones and environmental conditions

16. Tear film instability
Could be secondary to hyperosmolarity or prime to it
Is caused by;
• Reduced tear production
• Delayed tear clearance
• Reduced quantity and quality of lipid
• OS Irregularity and inflammation

17. Cont.…
Inflammation
The osmotic stress on ocular surface will result in the release of : IL-1B ,TNF-a ,IL-
8, MMP
This cytokines will result in localized autoimmunity
They also obstruct tearing reflex
• By stimulating release of opioids
• By directly binding to receptors
Once inflammation occur it will result ocular surface damage

19. Ocular surface microenvironment change in dry eye
Cornea
Corneal scaring, opacification and degeneration
Corneal thinning
Epithelial microvilli reduction
Central endothelial density reduction
NV, pannus formation and ulcers

20. Conjunctiva
• Squamous metaplasia
• Goblet cell reduction
• Conjunctivochalasis
Lacrimal gland
• Loss of secretory acinar cells
• Fibrosis and gland atrophy

21. Meibomian gland
• MGD
Eyelids
• Keratinization, thickening and neovascularization
• Blepharitis
• Recurrent Chalazion

22. Tear film
• Tear Hyperosmolarity
• Tear film instability
• Delayed tear clearance
• Increased tear film evaporation
Immune cells
• CD4 T cells are common
• Th1 and Th17

23. Nerve supply to ocular surface
DED corneas are characterized by reduced nerve density and altered
morphology
Reduced neuronal stimuli transmission to secretory component
Excessive cytokines inhibit release of Ach
Autoantibodies block receptors
Vascular system
Lymphangiogenesis- is due to chronic inflammation that will result macrophages
• Infiltrate cornea and transdifferentiate to endothelial lymphatics or
• Stimulate VEGF
Heamangiogenesis

24. Clinical presentation
Aqueous tear deficiency
• Burning, a dry sensation, photophobia, and blurred vision.
• Symptoms tend to be worse :
• Toward the end of the day,
• With prolonged use of the eyes or
• With exposure to environmental extremes
Evaporative Dry Eye
• Burning
• Foreign-body sensation,
• Redness of the eyelids and conjunctiva, and
• Filmy vision that is worse in the morning.

25. DIAGNOSIS
The diagnosis of DED needs a proper hx, examination and different testes.
History
Symptoms and signs
Exacerbation condition
Duration
Ocular hx must include
Medication(topical or systemic)
Contact lens wear
Allergic conjunctivitis
Previous ocular surface disease – HSV,SJS,GVHD
Previous ocular surgery
Punctal surgery
Bells palsy

26. Medical hx
Smoking
Dermatologic conditions
Menopause
Atopy
Systemic inflammatory conditions
Trauma
Radiation of orbit
Neurologic condition
Dry mouth, dental cavity and ulcers

27. EXAMINATION
External examination
Skin – scleroderma, rosacea
Eyelid – position, blink rate ,discharge, inflammation , Entropion, Ectropion
Adnexa – lacrimal gland enlargement, parotid gland enlargement
Proptosis
CN examination
Hand

28. SLE
Tear film - Height of meniscus, any debris,
mucus strands and foam
Eyelash
Eyelid - Abnormality of meibomian gland,
vascularization, keratinization and scaring
Punctum
Conjunctiva
Inferior fornix and tarsal conj. – mucus
thread, scaring erythema follicles and
papillary rxn
Bulbar conj. – keratinization, localized
dryness, chemosis , chalasis and

29. Cornea
Interpalpebral drying
Punctate staining
Thinning
Infiltrates
Mucus plaque
Filaments
Keratinization
Pannus formation, scaring,
ulceration and NV

30. DIAGNOSTIC TESTES
Testes for patients with underlying systemic condition

31. Tear Break-Up Time – is an indication tear film stability
 Can be measured:
 Invasively - with the instillation of fluorescein
 Best observed with use of a blue exciter and yellow barrier filter
 Appearance of a dry spot in less than or equal to 7 seconds is considered
abnormal
 Noninvasively using a keratometer or xeroscope
 noninvasive break-up time (NIBUT) – is the time from opening the eyes to the
first sign of image distortion is measured in seconds
 normal range for the NIBUT is 40 to 60 seconds
N.B- TBUT decrease in KCS, mucin deficiency and MGD

32. Ocular surface staining
Fluorescein sodium
• Common stain in ophthalmology
• Stain areas where corneal or conjunctival surface
epithelial cells are loose or desquamated
• Fluorescein uptake graded after the cornea is
divided into 5 areas
• Each area is graded for punctate staining on a
scale of 0 to 3 (the van Bjisterveld grading system)
• Scores > 3 indicates unstable tear film

33. Rose Bengal
• Is more sensitive for conjunctival staining
• Less tolerated than fluorescein
• Stain devitalized epithelial cells
• In ATD interpalpebral area is the common staining area

34. Lissamine green
Have similar staining characteristic of Rose Bengal
Much better tolerated than Rose Bengal
In summery

35. Testes for tear secretion
SCHIRMER I
 Used to evaluate aqueous-deficient dry eye
 This is done by measuring reflex tear secretion in response to conjunctival
stimulation
 The test is performed without anesthesia
Steps in doing the test
A. Place whatman #41 paper at the junction of the middle and lateral thirds of the lower
eyelid of each eye
B. Ask the patient to look forward and blink normally while the strip is held in place for 5
minutes
C. Record amount of wetting in millimeter
Interpretation of results:
Anything less than 10 mm is considered diagnostic of aqueous tear deficiency
Drawback - sensory and psychological stimuli
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36. 12/31/2020 36

37. CONT..
SCHIRMER II
 Measures reflex tear secretion in response to nasal stimulation
 Done like schirmer I test but with nasal stimulation by a cotton-tipped applicator
Interpretation of results:
Wetting of less than 15 mm after 5 minutes is associated with a defect in reflex
secretion
Drawback with test is patient discomfort
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38. 12/31/2020 38

39. CONT..
Phenol red thread test
 Phenol red is a ph sensitive dye
 Indicate tear volume by a schirmer-like test
 Measured over a period of 15 seconds
Interpretation of results:
 <6 mm is diagnostic
Meniscometry
 Is a noninvasive way to assess tear volume indirectly
 This is done by measuring the tear meniscus radius
 Dry eye patients have significantly smaller menisci than normal 12/31/2020 39

40. Meniscometry
• Is a noninvasive way to assess tear volume indirectly
• This is done by measuring the tear meniscus radius
• Dry eye patients have significantly smaller menisci than normal
MMP-9
The normal level is 3- 40ng/mL
Is done using inflammDry test

41. Tear Film Osmolarity
1. Tear Film Osmolarity
- effective & sensitive for diagnosing dry eye
- requires expensive equipment & skilled person
- doesn’t differentiate b/n tear deficient & evaporative dry eye
2. Tear Ferning
- depends on the ratio of Na+ & K+ to Ca2+ Mg2+
- diffences in electrolyte concentration related to different ferning patterns
- dry eye patients show less ferning

43. Management
Is dependent on severity of DED
Mild DED
Education – cessation of smoking, regular breaks and increase blinking during reading
Environmental modification like using humidifier
Revise both topical and systemic medication
If the severity increase
Aqueous enhancement using artificial tear, gel or ointment
Treat contributing factor
Correction of lid abnormality

44. Tear substitutes
Preservative-free tear substitutes are recommended
In mild cases we can use them with preservative
If installation of drops is frequent its better to use preservative free in mild cases
Emulsions ,gels and ointments can be used
Treat contributing factors like blepharitis and meibomianitis
Correct eye lid abnormality

45. Moderate DED
Mild DED Management plus
1.Anti- inflammatory medications
Cyclosporine a
• Inhibits the T cell activation and act as immunosuppression
• Inhibits apoptosis of lacrimal and conjunctival epithelial cells
• Dose is 0.005%
• Therapy is often initiated in combination with a short course of topical steroids
Tacrolimus – is macrolide and have an immunosuppressive effect
• Can be used in patients with GVHD,SJS and intolerance to cyclosporine
• Is prepared as 0.03%

46. Corticosteroids
Are highly effective in suppressing OS inflammation
Have to be used in low dose and infrequently for short duration(2 -3 wk)
Doxycycline and azithromycin
Dietary supplementation
Omega-3 fatty acids has been shown to increase average tear production and
tear volume
It also block the proinflammatory eicosanoids and cytokines

47. 2.Punctal plugs
• Use to retain lubricants and
inhibit the natural tear
drainage
• Are effective in patient with
ATD
• Can be temporary, reversible
prolonged and permanent

48. 3. Use of eyeglass side shields
This is to decrease tear film evaporation
Moisture retaining goggles, swimming goggles and gas permeable scleral
lenses could be used

49. Sever DED
In addition of the above treatments for mild and moderate DED we have to add
Secretagogues
Topical
Aqueous Secretagogues – Diquafosol tetrasodium 3%,lacritin
Mucin Secretagogues – rebamipide suspension increase MUC1,4 and
16experession
Lipid stimulation – IGF -1, androgen
Oral medication –to improve tear secretion by stimulation of lacrimal gland by inducing
cholinergic signaling pathway
Pilocarpine
-5mg po QID
Cevimeline - Is also a muscarinic agent acting as agonist on M1 and M3

50. • Autologous serum drop
• Can induce proliferation, migration and restore tight junction of OS epithelia
• Can be prepared from 3 to 4 red toped blood drown tubes
• Topical EGF - is also being tried to stimulate integrity of epithelium and
improve tear stability
• Human amniotic membrane
• Anti MMP-9
• Mucolytic - acetylcysteine 10% qid is used in filamentary keratopathy
• Permanent Punctal occlusion
• Limited tarsoraphy

51. Prognosis and Follow up
Most patient who keep up with their regimen could function either symptom free
or with minimal difficulty
Frequency and extent of follow up depend on
Severity
Therapeutic approach and
Response
On follow up evaluation we have to monitor for any OS damage

54. REFERENCE
• BCSC ,Section 8
• KANSKI 8TH EDITION
• PRACTICAL OPHTHALMOLOGY FOR BEGINNERS
• DRY EYE SYNDROME PPP BY AAO
• INTERNATIONAL JOURNAL OF MOLECULAR SCIENCE
• eyewiki.com
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