2. PREFACE
• The main aspect of this project is to show the
different tear function test to show any abnormality
in the tear film or tear film dysfunction.
• This give us a brief idea about the abnormality and
proper care to be taken in ocular surface disorders.
This project has been explained in simple and
illustrative manner about the different condition of
tear film dysfunction.
This project has explained about the different test that
has to be done to assess the tear film dysfunction.
3. ACKNOWLEDGEMENT
• THIS PROJECT HAS BEEN COMPLETED IN SUPPORT
OF MANY PEOPLE, OTHERWISE IT WAS NOT
POSSIBLE FOR ME TO PREPARE THIS PROJECT . I
WANT TO GIVE MY SINCERE THANKS TO
DR.AGRAWALS’ EYE HOSPITAL FOR ALLOWING ME
TO COMPLETE MY INTERNSHIP HERE.
• I WOULD LIKE TO THANK NSHM KNOWLEDGE
CAMPUS, DURGAPUR FOR GIVING ME SUPPORT.
• LAST BUT NOT THE LEAST I WOULD LIKE TO THANKS
MY FACULTIES, MY SENIORS , FRIENDS AND MY
COLLEAGUES FOR THEIR SUPPORT.
4. Tear Film- introduction
It covers the exposed part of
the globe i.e., the cornea
and the bulbar conjunctiva
It remains most directly in
contact with the
environment
Imp for protecting the eye
from external influences
aqueous
5. Function of Tear Film
For maintaining health of the underlying
structures
To maintain the optical stability
Antibacterial Function
Provides Corneal Nutrition
Mechanical function by flushing cellular debris, FB
from cornea & conjunctival sac & by lubricating the
surface
6. Structural components of Tear film:
Outer lipid layer
Middle aqueous layer
Inner mucin layer
To retard the evaporation of the aqueous
To lower the surface tension of the tear film
To lubricate the eyelids
To supply atmospheric O2 to the
avascular corneal epithelium
Antibacterial function
To wash away debris and allow the
passage of leucocytes after injury
Lubrication
Protection by covering FB with a
slippery coating
Converts hydrophobic into Hydrophilic
surface
7.
8. Physical properties of Tear film
98.2% H2O
1.8% solids
pH 7.3-7.7
310-334 mOsm
RI 1.37
11. Deficit aq.
production Evaporative
Sjogren’s
syndrome
Non Sjogren’s
syndrome
Meibomian
Gland Disease
Exposure
Keratopathy
CL
AbnormalityPrimary 2ndary
Lac. Gland
Disease
Lac. Gland
Obstruction
Loss of Reflex
Tearing
Ocular irritation
Tear film instability
Ocular surface
dysfunction
s
Age
Related
12. Lac glands
Brain
Neuronal feedback loop for tear production
Ocular surf
produces neural
stimulation
Secretomotor
nerve impulses
Ocular surfaceTear supports and
maintains ocular
surface
13. Change in the neuro-secretory arc/
Changes in immunomodulation of
the lac gland
Disruption of the
feedback loop
Diminution of neural tear
stimulus
Sensory nerves will adapt
to prolonged sureface
irritation
Decrease the
stimulus for
reflex tearing
Ocular surface
dessication
16. Chief C/O the patients with Tear Film
dysfunction
Burning or Itching
Fluctuating Vision
Foreign Body Sensation
Grittiness or irritation
Watering or excessive tearing
Sore or tired eyes
History of Styes
Ocular Discharge
Light sensitivity
Contact Lens Discomfort
17. History taking for a Dry Eye(DE) patient…..
Duration of reading or computer use
Whether using contact lens
Living in arid condition
Living in air conditioned environment
Frequent air traveling
Addiction to cigarettes
Exposure to environmental allergans or systemic
allergies
Any recent diagnosed hormonal change
Autoimmune diseases
CRx (sply oral antihistaminic, antidepressants,
hormone replacement therapy,etc.)
20. Diseases related to dysfunction in tear
film
Evaporative Dry Eye
Oil deficiency- secondary to
obstructive meibomian
gland dysfunction
Defective resurfacing of the
eye by the tear film (result
of poor blinking or
abnormal lid-globe
congruity)
21. Dry Eye: Multifactorial nature
Elderly woman
Contact lens
user
Post
menopausal
Taking
glaucoma
medications
Working for long
hours in front of
computer
Air-conditioned
environment
22. Diseases related to dysfunction in tear film
Lacrimation from
excess tearing
Obstructive
epiphoria as a
result of failure of
tear drainage
( Schirmer’s
value)
23.
24. Early Signs of Tear Dysfunction
Precorneal Tear Film
Presence of an increased amount of mucin strands and debris
In Chronic Dry Eye(CDE) lipid contaminated mucin
accumulates
Marginal Tear Strip
MTS is reduced in height (0.3mm)
Attains concave shape
In CDE it can be absent
25. Tear Film Break-up Time(BUT)
It is the difference b/w the
last blink and the first
randomly appearing dry
spots
Assessed with fluorescein
and cobalt blue filter in
broad beam
Avg of three reading is
taken
Suspect Dry Eye when
BUT<10secs
26. Causes of Tear Film Destability
Tear Film rupture occurs when hydrophobic lipid
diffuses from the superficial layer and contaminates
the underlying hydrophilic mucin layer
Epithelial change (like poor secretion of glycocalyx)
can cause poor adherence of tearfilm
27. Schirmer’s Test
Rate of tear formation is
estimated
Whatman filter paper no 41 is
used
Dimension 5mm X 35mm
5mm tab is folded at one end
The bent end is placed at the
junction of the lateral 1/3rd
and
medial 2/3rd
of the lower
conjunctival sac
The test is performed in dim
light with fans and ACs
switched off
28. Schirmer test
Without Anesthesia
Measures Reflex Tear
Secretion (dry eye = <
6mm wetting)
With Anesthesia
Measures Basal Tear
Secretion (dry eye =< 3mm
wetting)
29. Rose Bengal
staining
Rose Bengal solution 1%
placed into the conjunctival sac.
After a wait of 2 mins, degree of rose bengal staining on bulbar
conjunctiva and cornea is quantitated by microscopic exam.
Stains devitalized cells.
Also stains mucous strands (very often present in KCS)
J Am Optom Assoc 1991, 62:187-199
31. Phenol Red Thread test
A sterile cotton thread is draped
over the non-anesthetized lid
margin
It changes color upon aqueous
contact and the length of
colored thread is measured
This test is used to evaluate the
tear secretion quantity without
inducing significant reflex
tearing
The normative value is 13±4 mm
of wetting over a fifteen second
period
32. Impression cytology
Removal of superficial layers of conjunctival epithelium
Application of circular discs of cellulose acetate filter paper
for a certain period of time.
Obtained specimen observed under microscope for signs
and symptoms of squamous metaplasia or presence of
inflammatory cells.
In CDE conditions the cells appear fewer, irregular in size &
shape and takes up stain less uniformly
J Am Optom Assoc 1991, 62: 187-99
34. Lysozyme Assay
Hyposecretion of tears may be due to the reduction in the
concentration of lysozyme
Wetted filter strip is placed into an agar plate containing
specific bacteria
The plate is incubated for 24 hrs and the zone of lysis is
measured
The zone will be reduced if the concn of lysozyme in tears
is decreased
35. Tear Globulin Assay
Decreased tear formation may be due to dec
IgA
Performed on spl tripartigan immunodiffusion
plates containing specific agar gel in wells
Twenty microliters of tear samples is put into
these wells and the plates are incubated for 48
hrs
The diffusion of rings around wells are
measured to nearest 0.1mm with partigen ruler
The ring will be reduced if the concn of Iga in
tears is decreased
37. Jones-I (primary) test
Differentiates excessive watering due to blockage in lacrimal passage
with primary hypersecretion of tears
1 drop of 2% fluorescein in instilled in the conjunctival sac
After 5mins a cotton tipped bud (moistened with 4%proparacaine) is
inserted under the inferior turbanate
Fluorescein if recovered from the nose then the excretory system is
patent
Otherwise should go for Jones-II test
38. Jones-II (Secondary) Test
Helps to identify the probable site of partial obstruction
4% xylocaine in instilled in the conjunctival sac
Any residual fuorescein is washed out
NLD is irrigated with normal saline
The patient is positioned his/her down by 45deg
+ve –fluorescein stained saline recovered from the nose showing
functional patency of upper lac passage
-ve- unstained saline recovered from the nose shows block in the
upper lac passage or defective lacrimal pump mechanism
40. Tearscope
Assess patient's tear film quantity, quality and
stability
Non invasive method
Tear quantity is assessed with one full-length view
along the tear meniscus
Tear quality is assessed by matching the patient's
tear film with the equivalent pattern in the Guillon-
Keeler Tear Film Grading System, and by viewing the
tear film flow dynamics.
Tear stability is assessed by directly viewing the tear
film on the contact lens or corneal surface and
measuring the non invasive break up time
42. a) normal smooth tear film that is the most representative case, b) post-blink roughness
that usually lasts no longer than two seconds, c) bubbles, d) ridges produced by the
eyelids, e) unusually rough tear surface, f) tear break-up, g) and h) are typical rough tear
surface typical of contact lenses.
Tearscope- it
depends on the
principle of
INTERFERENC
E
43.
44. Take Home Messages…
Ocular surface disorders related to tear film
dysfunction is a complex condition
It requires careful observation, knowledge about
various diseases and their etiologies, and a
thorough ocular and systemic history
It is crucial to diagnose the correct disease
mechanism prior to considering management of
any kind
In many situations there may be multiple causes
and only careful assessment over multiple visits
will lead to the correct diagnosis and proper
treatment plan
