Materials and Methods: 130 eyes of 65 cases were included in the study. CCT values were measured for each eye, and IOP values were then measured using NCT and OBF-pneumotonometer devices. IOP measurements obtained with both devices were compared statistically.

Results: Mean CCT value of the eyes in the study was 524.08±33.95 μ (433-607). Mean IOP values measured using NCT and OBFpneumotonometer were 15.57±3.25 (9.1-22.4) and 17.77±3.73 (9-23.9) mmHg, respectively. Although the differences in IOP measurements between the devices were statistically significant (p<0.001), the two devices exhibited a high degree of correlation with one another (r=0.8, p<0.001) and at Bland-Altman analysis the differences in IOP values were generally within±2SD. In addition, IOP values measured using both devices were affected by CCT values (r=0.385, p<0.001; r=0.435, p<0.001, respectively). For each 10-micron increase in CCT values, an increase of 0.37 mmHg for IOP values measured using NCT and a 0.48 mmHg increase for IOP values measured using OBF-pneumotonometer were observed.

Conclusion: Results from NCT and OBF-pneumotonometer are proportional to one another. The OBF-pneumotonometer generally produces higher IOP values than NCT. However, this variation is not affected by CCT values. Interchangeable use of the two devices is not recommended in clinical practice. It is important that CCT values be borne in mind in assessing IOP values measured using the two devices. Keywords : Cornea, corneal pachymetry, glaucoma, ıntraocular pressure, tonometry, ocular