Tonometer

1. TONOMETERY
Presented by :
B.OPTOM

2. Contents :
1. Introduction to Tonometery
2. What is IOP ?
3. Measurement of IOP
4. Classification of Tonometery
5. Clinical uses

3. INTRODUCTION :
TONOMETER –It is a device that measures the Intraocular
pressure.
•Most tonometers are calibrated to measure pressure in
millimeters of Mercury (mmHg).
•NORMAL IOP -: 10-20 mmHg

4. CLINICAL USES -:
1. Diagnosis and management
2. Abnormally high IOP.
3. Suggest the presence of Glaucoma.

5. TONOMETERY
DIRECT
Manometery
INDIRECT
1.Indentation
2.Applanation

6. MANOMETERY –
• measured by inserting a cannula directly into the
anterior chamber which is connected with manometer.
Disadvantage –
Needs general anesthesia.
• Not practical method for human beings.
Use –
•For experiment, research work on ANIMAL eye.

7. INDENTATION TONOMETER :
SCHIOTZ TONOMETER –
PRINCIPAL –
Based on principal that a plunger will indent a soft eye more than
a hard eye.

8. PROCEDURE-
•Sterilization.
•Paitent counseling
• Supine position.
•Topical anesthetic.
•Fixation target(Thumb).
•Place tonometer directly onto the cornea vertically.
•Note scale reading.
•Antibiotic.
ADVANTAGE – Cheap , Portable ,Very good for camp screening.
DISADVANTAGE- False reading , corneal abrassion.

10. APPLANATION TONOMETER
Contact
1.Goldman
2. Perkins
Non-Contact
1. Air puff
2. Pulse air

11. GOLDMAN TONOMETER :
•Concept was introduced by Goldman in 1954.
•Consists of double prism mounted on a standard slit lamp.
•BASED ON – Imbert- Fick Law.
P=W/A

12. PROCEDURE -:
•Paitent counselling .
•Pt comfortably positioned.
•Topical anesthesia.
•Place fluorescin strip in the lower fornix.
•Room light should be dimmed.
•Chin rest.
•Cornea and biprism is illuminated by cobalt blue filter light .
•These prisms are then advanced untill it just touches the apex of
cornea.
•At this point 2 semi circles are viwed.

13. Advantages
•Accurate reading
•No indentation
Disadvantages
•Need slit lamp
•Dark room procedure
•Staining light necessary

14. PERKIN’S HAND HELD:
•Same type of Goldman applanation tonometer.
•Used with pt in any position.
•The light source is powered by battery.
ADVANTAGE – Portable, usally used
infants and in children.

15. TONOPEN -:(Mackay-Marg)
1. Including its power source
• Wt only 60g.
• 185 mm long.
• 25 mm wide.
2. Fully portable
3. Pocket tonopen.
4. Held in any position
5. It converts IOP into electric wave.
Advantage – Portable, useful in pts with nystagmus, useful
in scarage cornea
Disadvangte- Costly ,Required in supine position.

16. NON CONTACT TONOMETER:
A]AIR PUFF -
•Applanates the cornea by means of jet of air.
•IOP readings compare favourably with goldman tonometery.
ADVANTAGE –Instrument is beneficial in mass Glaucoma
screenings .
•Requires no anesthetics with proper use.
•No risk of injuring the cornea.
B]PULSE AIR –
Non contact tonometer that can be used in any position.

17. THANKYOU