Comparison Of Intraocular Pressure (IOP) Measured By Non-Contact (Air–Puff) Tonometer Compared With Goldmann Applanation Tonometer

Background: Measurement of intraocular pressure is one of the most important examination procedures in ophthalmic clinics, IOP is an important parameter in the diagnosis of glaucoma. There are numerous types of tonometers available, it is important to evaluate the differences in readings between different tonometers. Goldmann Applanation Tonometers and non-contact Air-Puff Tonometers are largely available in ophthalmic clinics.Aim: The purpose of this study is to evaluate the difference between IOP measurements taken by a GAT and those taken by an Air Puff Tonometer and to observe the reliability of Air Puff to be a screening tool.Material and Methods: This study was performed on 200 eyes from 100 study participants (including: Relatives of patients, medical students, nurses and patients complaining from errors of refraction). attending an ophthalmic outpatient clinic. visual acuity, Refraction, fundus examination, corneal thickness were assessed for each participant; Also, each patient’s IOP was measured using both GAT and Air-Puff tonometry, the difference in readings between the two methods were calculated.Result: The mean IOP measured by GAT was 14.48±2.29 mmHg, while that measured by Air Puff tonometer was 16.34±2.3 mmHg. The mean difference between the two methods of measurement was 1.855 mmHg. The readings obtained by Air Puff tonometer were higher than those obtained by GAT and highly statistically significant.Conclusion: The non-contact, air puff, tonometer produces IOP measurements which are similar & consistent to that of gold standard GAT. Our study indicated that there is a good consistency between the non-contact Air-Puff tonometer and GAT.