2. Definition :-
It is the procedure
performed to determine
the intraocular pressure
(IOP)
3. Def. of Glaucoma
It is the characteristic
and progressive condition
of the eye which is raised
the intraocular pressure
occurs progressively damage
the optic nerve fibers due
to gradually loss of vision.
4. Direct Indirect
Manometer
DIGITAL INDETATION
(Schiotz)
APPLANATION
(Goldman)
NCT
Types of
Tonometer
Perkin’s
5.
6. Procedure:-
-Cannula inserted into the the Eye
-Then connected to a tube of
calibrated in cm of water or mercury(mmhg)
Disadvantage :-
-Not clinical method
- Needs Anaesthesia
7.
8. Principle:-
-Based on Palpation By the Examiner
Procedure:-
-Pt looks Down
-Index finger of both hand used one
finger push eye ball above tarsal plate that
time other finger palpation the process.
10. Indentation tonometer
(Schiotz)
Principle:-
- Amount of the
indentation depends upon IOP
-The higher IOP the lesser
Indentation
-The lesser theIOP the
deeper the indentation
11. HENCE
-Less reading on scale ----
High IOP
-Scale reading have to be
converted to IOP by the help
of chart (Friedenwald
conversion table)
12. Base plate of
tonometer resting
on cornea
Plunger of
tonometer Indenting
the cornea
Fig.1 In this cornea is indented
14. Process :-
-Patient in supine position
- 4%lignocaine/proparacaine
-looking up at a fixation target
Advantage:-
- Fast
- Very good to camp screening
- Portable
- Cheep
- Easy to cleaning & maintenance
- No required Slit lamp / electricity
15. Disadvantage :-
- Reading effect by corneo
scleral rigidity
- Can not be done in injury
cases/early post-op
Cleaning& Mantanance:-
- Cleaning after the removed from
barrel with
> Alcohal
> Methylated spirt
16. Calibration:-
This instrument
should be calibrated before each
use by placing on pseudo cornea
and be sure checking scale
reading is zero.
17. Applanation tonometer
Principle:-
-Applanation tonometer
based on IMBERT FICK LAW
- Biprism tip flattens
- A Biprism convert
applantion area into half alignment of
2 half give the correct IOP reading
- Applanates a small
area of cornea central 3.06mm.
18.
19. F- Force
A- Flattening of the area
P- Pressure in side the
Eye
IMBERT FICK LAW
20. Parts of Applanation tonometer
Connects to the
slit lamp
Biprism
(measuring
prism)
Feeder
arm
Control weight insert
Housing
Adjusting knob
21. Equipment:-
-Housing control the prism
movement
-Neck
-Biprism plastic Biprism with a
mirror to slit corneal applantion image to 2
halves
22. Process:-
-slit lamp
-4% xylocaine
-Dark room
- Flurosceine stain of tear film
-Cobalt blue light
-Biprism applanation cornea with
knobs reading at (1)
-Reading read on knobs scale
multiplied by 10 ====IOP
23. Advantage:–
- Most accurate .
-No indentation so not
much force applied on cornea.
-Does not effect by
cornea scleral rigidity .
-Reading directly read
from knob .
-Can be done on post op
case /injury cases .
25. Calibration:-
◦ Appl, tonometer is calibrated with
calibration bar.
◦ It should be done once in a weekly or
monthly depend upon uses.
26. NON CONTACT TONOMETER
Principle :-
A puff of air creates a
constant force that momentarily
flattens the cornea and internal
reference point to the movement
of flattening is measured and
converted into IOP .Directly
reading on display.
29. ADVANTAGE ;-
-Quick .
-No anesthetic required .
-May be delegated .
-Nothing contact to the Eye .
30. DISADVANTAGE :-
-Expensive .
-Difficult on to obtain reading on
scarred cornea , soft Eye
-Not partable .
.
31. Perkins Tonometer
It uses the same biprism as the Goldmann
applanator.
The light source is powered by battery.
The readings are consistent and compare quite well
with the Goldmann applanator.
