A Comparative Study Between the Goldmann Applanation Tonometer and the Non-Contact Air-Puff Tonometer (Huvitz HNT 7000) in Normal Eyes

Abstract

Objective

To assess whether the non-contact air-puff tonometer (NCT) is an appropriate alternative to the Goldmann applanation tonometer (GAT) for measuring intraocular pressure (IOP).

Patients and Methods

An observational, cross-sectional, and comparative study with a quantitative approach was carried out. Two techniques for IOP measurements using the standard GAT and the NCT were compared. A total of 180 eyes from 90 patients were included in the study.

Results

The total mean IOP according to NCT measurements was 14.12 mmHg, and the total mean IOP according to the GAT was 12.98 mmHg; these values were significantly different (p=0.0018). When dividing the participants into three groups according to the measurement range obtained and comparing the mean NCT and GAT measurements in each group, in Group 1 (10–15 mmHg), no statistically significant difference was found between the means of the two tonometers (p=0.3100), a difference was observed between Group 2 (16–19 mmHg) and Group 3 (20 mmHg or more) (p<0.001). When dividing the participants by age group, the means obtained by the two tonometers also differed significantly between Group 4 (40–59 years) and Group 5 (60 years or more) (p<0.0001). In all groups, the mean measurements by the NCT were higher than those by the GAT.

Conclusion

The NCT presented an approximate mean of the measures with the GAT in group 1 but was overestimated in the measurements of the groups 2 and 3.

Keywords:

• ocular tonometry
• glaucoma
• ocular hypertension
• intraocular pressure
• efficiency

Abbreviations

IOP, intraocular pressure; GAT, Goldmann applanation tonometer; NCT, Non-contact air-puff tonometer.

Ethics Approval

Ethics approval was obtained from the research ethics committee of the Universidade do Oeste de Santa Catarina by number 3,412,730.

Author Contributions

All authors made a significant contribution to the work reported, whether that is in the conception, study design, execution, acquisition of data, analysis and interpretation, or in all these areas; took part in drafting, revising or critically reviewing the article; gave final approval of the version to be published; have agreed on the journal to which the article has been submitted; and agree to be accountable for all aspects of the work.

Disclosure

The authors declare no conflicts of interest for this work.

Additional information

Funding

No funding was received.