Dry eye simplified

1. DRY EYES
Dr. NITISH

2. CONTENTS
• DEFINITIONS
• PHYSIOLOGY
• CLASSIFICATION
• CLINICAL FEATURES
• SPECAIAL INVESTIGATIONS
• TREATMENT

3. DEFINITION
• It is a non infectious ocular surface disorder due
to deficiency or absense of tear fluid.
• Ocular surface describes the entire epithelial
surface of the external eye,encompassing the
corneal epithelium as well as bulbar and
palpebral conjunctival epithelium.
• Ocular surface along with a normal tear film over
it forms a single functional unit.

4. THE TEAR FILM
• Has three layers
LIPID LAYER
AQUEOUS LAYER
MUCIN LAYER

5. LIPID LAYER
• Outermost layer of the tear film.
• Mainly secreted by meibomian glands
• Meibomian gland openings are situated on the lid
margin immediately behind the lash follicles.
• Lipid layer consist of waxes and cholesterol esters
with polar components
• FUNCTION-stabilise the tear film,help in uniform
spreading,and reduce evapoation of aqueous
layer

6. Aqueous layer
• Secreted by lacrimal glands(main as well as
acessory).Its secretion is modulated by sensory as
well as reflex arcs.
• Water makes 98% of tear volume.also contains
lysozyme,immunoglobulins,inorganic
salts,glucose,urea,trace elements.
• FUNCTIONS-provides hydration,lubrication,and
oxygen.helps in removing debris
constantly.provides protection against infection

7. Mucin layer
• Innermost layer.
• Secreted by goblet cells. Covers cornea and
conjunctiva.mucin comes to lie over the cornea
while blinking of the lids.
• Mucin is a glycoprotien and it converts a
hydrophobic corneal surface into hydrophilic one.
• Impression cytology provides information on
number and health of the goblet cells.
• FUNCTION-It provides surfactant and stability to
the aqueous film.

8. Normal blinking
• Is critically important in spreading freshly
secreted tears.
• Normal blink averages once every 5 sec.
• When eye remains open for a long time
discontinuity (dry spots ) develop over the
tear film.the time interval taken for the
discontinuity to develop is called tear film
break up time(TBUT)
• Normal TBUT is 10-40sec

9. Classifications
• Aqueous layer deficiency
-sjogren syndrome
-non sjogren syndrome
-dacroadenitis
• Mucin deficiency
-steven johnson syndrome
-ocular phemphigoid
-chemical burns/radiation damage

10. • Lipid abnormality
-meibomian gland dysfunction
-Posterior blepharitis
• Evaporative causes
-severe proptosis/increase palpebral fissure
-facial nerve palsy
-nocturnal lagophtalmos

11. • Other causes
-decrease corneal sensation
-hypovitaminosis a
-medicamentosa
-menopause
-post lasix
-environmental factors

12. Aqueous layer deficiency
Sjogren syndrome-it is a systemic autoimmune
condition characterised by lymphocytic
infiltration of exocrine glands and mucus
membranes resulting in reduction in
secretion leading to abn in tear film and
ocular surface disease
• Classified as primary when it exist in isolation
and secondary when asssociated with
diseases such as RA,SLE,systemic sclerosis

13. • Diagnostic criteria-symptomatic
It presents with dry eye symptoms along with dryness of
mouth(xerostomia)swollen salivary glands or freq need
to drink water.
Objective-objective evidence of kcs
-positive involvement of minor salivary gland on labial
biopsy
-salivary involvement demonstrated by sialography or
scintography
-lab evalun for extractable nuclear antigens,ANA ,RF

14. Hyposecretion is also seen in a rare congenital condition
called RILEY-DAY SYNDROME which affects the ANS
Non sjogren
-primary age related hyposecretion
-lacrimal tissue distruction by tumoror inflammation
-surgical removal or congenital absense of lac gland.
Dacroadenitis
-mumps,IM,sarcoidosis etc

15. Mucin layer deficiency
Stevens-johnson syndrome
Ocular manifestation-conjunctival bullae
formation,keratopathy,and sec infecn.in chr cases
subepithelial fibrosis takes place resulting in
fornix shortening,symblepharan,meibomian
gland compromise and keratinisation of
conjunctiva
Sev loss of goblet cells and dec in mucin secretion.
Corneal ep defect,neovas,stromal ulceration, and
scarring-blinding complications

16. • Ocular phemphigoid
-produces scarring of the conjunctiva and other
mucous membranes.
It is a cicatrizing process resulting in loss of
goblet cells,compomising lacrimal ductules,
and meibomian gland openings.
Sec complicns-trichiasis,ep defect formn,corneal
epitheliopathy & corneal vascularisn-
permanent tear film abn.

17. Burns/chemical injuries/radiation injury
-cornel opacity,severe inflammation and limbal
ischemia.there is severe loss of goblet cells
resulting in severe kcs.
Sequele-corneal opacity,conjunctivalization of
cornea,conjunctival scarring,fornix
foreshortening,lid deformities-lead to severe
ocular surface disorder.

18. Lipid layer deficiency
• Miebomian gland dysfunction-as a sequel or
in assocn with meibomitis.
In pts with mgd there is closure of meibomian
gland orifice.
Posterior blepharitis-has symptoms of kcs along
with lid margin irritation
o/e-crusting at the base of eyelashes

19. Evaporative states
• Increased evaporation can be sec to
meibomian gland dysfunction or increse
palpebral fissure.
• Pt c/o as the day progress
• Pt can have excess tearing as lacrimal gland is
functional.

20. Other causes
• Decrease corneal sensation-decreases tear
secretion and increases tear osmolarity.
• Medicamentosa-suspected in pts using e/d
wth preservatives for more than qid as the
preservative is toxic to the ocular
surface(goblet cells)

21. Clinical features
May be trivial like ithching or burning to serious
one like blindness.
Foreign body sensation,excessive
secretion,burning,redness,photophobia,inabili
ty to tear for irritation or emotion
Non specific symptoms like
tiredness,headache,haeviness of the eye.

22. Signs
Conjunctiva may show mild keratinization and
redness
Tear film-in the dry eye lipid-contaminated mucin
accumulates in the tear film as particles and
debris that move with each blink.
Tear meniscus becomes thin or absent.
Froth in the tear film or along the eyelid margin
occurs in mgd

23. • Cornea
Punctate epithelial erosions
Filaments consist of mucus strands lined with
epithelium attached at one end to the corneal
surface tat stain well with rose bengal
Mucus plaques consist of semi-
transparent,white-grey,slightly elevated
lesions of various sizes.

24. • Complications-peripheral superficial corneal
neovascularisation,epithelial brek
down,melting,perforation and bacterial keratitis

26. Diagnosis
• HISTORY
• EXAMINATION
• INVESTIGATIONS

27. EXAMINATIONS
• SLIT LAMP BIOMICROSCOPY-
Tear meniscus should be examined a the lid
margin.n=1mm,<0.5mm indicative of tear deff
Increased debris or mucin strands.
Irregular corneal surface.
Meibomian gland dysfunction or blepharitis.
symblepharan

28. • FLUORESCEIN STAINING
Shows area of denuded corneal epithelium and
punctate staining of cornea.
• ROSE BENGAL STAIN
Stains devitalized tissue.stains conjunctival and
cornea ep as well as mucus threads and
corneal filaments.

29. • TBUT
After staining the conjunctival film with
fluorescien,the pt is asked to blink and keep
eyes open.
Time interval b/w the last blink and first
appearnce of random dry spot is measured.
Time<10sec-mucin deff
N=30sec

30. Investigations
• SCHIRMER’S TEST-test devised to measure the
aqueous tear production or tear flow in dry eye
pts
• Done with a strip of filter paper(whatman no 41)
measuring 5mm by 35mm long.
• Schirmer’s test 1-with TA & measures basic
secretion
• Schirmer’s teat 2-without TA & with nasal
mucosal stimulation.measures basic + reflex tear
secretion.

32. • TEAR LYSOZYME ASSAY-produced by
tubuloacinar cells of main and acessory
lacrimal glands.
Reduced when tear formation is reduced.
LACTOFERRIN RADIAL IMMUNODIFFUSION
ASSAY-measures lactoferrin content of tears.it
closely relates to the tear secretion by the
lacrimal gland.

33. • FLUORESCEIN DILUTION TEST-the speed at
which 1.5 microlitre of 5% fluroscein gets
diluted give an idea abt tear flow.
• TEAR OSMOLARITY-297-309mosm/l
In kcs it is increased.
CONJUNCTIVAL SCRAPPING-stained with geimsa
stain.

34. • CONJUNCTIVAL IMPRESSION CYTOLOGY-tseng classified squamous
metaplasia into 6 stages
Stage 0-normal epithelium,mod no of goblet cells.
Stage1-early loss of goblet cells with no keratinization,dec GCD,N/C
ratio 1:2
Stage2-total loss of goblet cells without keratinization,ep cells mod
enlarged,N/C1:4
Stage3-early &mild keratinization,ep cell markedly
squamous,metachromaticchange in the cytoplasm,keratin filaments
visible in some ep cells,N/C ratio 1:6

35. • Stage 4-mod keratinization,large
metachromatic squamous ep cells,densely
packed keratin filaments,keratohyaline
granules & pyknotic granules,N/C 1:8
• Stage 5adv keratinization,shrunken
cytoplasm,and densely packed keratin
filaments in which nuclei markedly pyknotic or
enucleated

36. • TEAR FERN TEST-tears when dried on slide
show ferning.
• PHENOL RED THREAD TEST-uses a thread
impregnated with a ph sensitive dye.
• TEAR MENISCOMETRY-quantify the height n
thus volume of lower lid meniscus.

37. management
SUPPLEMENTATION OF TEARS
PRESERVATION OF TEARS
TREATMENT OF ASSOSIATED CONDITIONS

38. TEAR SUBSTITUTES
Ideal tear substitute-comfortable soothing effect
Proper wetting agent, buffer, and a preservative
Ph RANGE 7-8.5 & osmolarity around
300mosm/l
Should not produce epithelial toxicity

39. • Cellulose derivatives-are
viscous,transparent,non irritating,water
soluble compounds.
-carboxy methyl cellulose 1%(deposits on
eyelashes)
-hydroxy propyl methyl cellulose 0.3-0.5%(poor
contact time)
-hydroxy ethyl cellulose 0.44%(short duration)

40. • Carbomers-cling on eyelashes and lasts longer.
-carbomer 980 0.2%
-carbomer 974 0.25%
Polyvinyl alcohol-increases the persistence of
the tear film & useful in mucin deff
-PVA 1% & 1.4% drops

41. • Povidine-polyvinylpyrolidine 5%drops
• Lipids and oils-soft paraffin,liquid paraffin
ointments used at bed time
• Acetylcysteine 5%-mucolytic in nature.useful
in pts with corneal filaments and plaques
• Autologous serum can be used

42. Tearconservation
• Punctal occlusion
1. Temporary occlusion-inserting collegen plugs
into the canaliculi that desolves in 2-3 weeks
2. Reversible prolonged occlusion
3. Permanent occlusion-in severe dry eye with
repeated schirmer test values <5mm
• Reduction of room temperature and using
room humidifier
• Tarsorrhapy

44. Antinflammatory agents
• Low dose topical steriods
• Topical cyclosporine reduces t-cell mediated
inflammation of the lacrimal gland and
reversal of sq metaplasia and increase in GCD

45. Contact lenses
• Low water content HEMA lenses – moderately
dry eyes
• Silicone rubber lenses – contains no water and
ready transmits O2, effective in protecting the
cornea in extreme tear film deff
• Occlusive gas permeable scleral contact
lenses-provide reservoir of saline over the
cornea. Useful in xtremely dry eyes on
exposure

46. Surgical measures
• Conjunctival autograft
• Limbal transplantation-severe
chemical,thermal burns,stevens johnson
syndrome.
• Amniotic membrane transplant-severe ocular
surface disorder in which there is no ep
component & no tear supply.SJS

47. Treatment of blepharitis and MGD
• HOT COMPRESS WITH LID MASSAGE
• LID HYGIENE
• TETRACYCLINE-post blepharitis & MGD

48. Other options
• Botox inj into the lid
• Oral cholinergics
• Zidovudine
• Submandibular gland transplantation
• Retinoic acid

49. References
• Jack J Kanski-6th edition
• Mayron yanoff 2nd edition
• Dutta 2nd edition
• Sunitha agarwal
• Various internet sites