This presentation includes - ✓History of NCT ✓Introduction of NCT ✓Classification of NCT ✓Parts of NCT ✓Principles of NCT ✓Advantages and disadvantages of NCT ✓Errors of NCT

1. Presented by:
ATIKUR RAHMAN
Department of Optometry,
RIPANS

2. CONTENTS :
History of NCT
Introduction of Tonometry
Classification of Tonometry
NCT
NCT
Parts of NCT
Principle of NCT
Advantages & disadvantage of NCT
Errors of NCT
References

3. HISTORY:
 The first inventor of NCT was the German
ophthalmologist Erich Zeiss.
ophthalmologist Erich Zeiss.
 Goldman also developed a NCT in 1972.

4. INTRODUCTION
TONOMETRY :
• It is the procedure performed to determine intra-
ocular pressure (IOP).
ocular pressure (IOP).
 Tonometer is use in tonometry for measuring IOP.
 The normal range of IOP from 10 – 21 mmHg.

6. CLASSIFICATION OF TONOMETRY
 DIRECT TONOMETRY
Manomatry
 INDIRECT TONOMETRY
Digital tonometry
Digital tonometry
Indentation tonometry
Applanation tonometry
Non-contact tonometry

7. NON-CONTACT TONOMETER
 Basically it is an Applanation tonometer

8. PARTS OF NCT:
 Alignment system
 Optoelectronic applanation monitoring
system
system
 Pneumatic system

10. PRINCIPLE OF NCT
 It determine IOP by measuring time interval between
initial generation of air puff to the point where timing
device stop. It take less time for air puff to flatten a soft
eye than it does for a hard eye.
eye than it does for a hard eye.

11. ADVANTAGES OF NCT
Doesn’t require any anesthesia
Easy to perform
Require less time
No direct contact with the patient
No direct contact with the patient
Less chances for infection

12. DISADVANTAGES OF NCT
Accuracy of the instrument decrease with increase in
IOP.

13. VID-20230907-WA0004.mp4

14. ERRORS IN NCT
Corneal opacity
Hazy media
High astigmatism
Low visual acuity
Low visual acuity

15. REFERENCES
“Manual for Ophthalmic instruments & Clinical
procedures ” by Manjusha Lakshmi M
www.nilapublication.com
www.alamy.com
www.alamy.com
www.istockphoto.com
www.dreamstime.com

16. THANK YOU !
THANK YOU !